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Simple TCP Chat Client Code Review and Questions

I am relatively new to programming and I took it upon myself to make a simple chat application; think AIM from back in the day. This is more of a request for a code review than a list of questions. For the most part, the application works with a few minor errors which I will highlight below. Please see the code from the project: https://github.com/N8STROMO/Basic-Chat-Tcp as well as the code listed below. Questions are embedded along the way. Thanks for any help you may be able to provide!
Here is the Server Code: Server.cs
namespace Server
{
public class Server
{
// This is the port that the server will be listening on
const int PORT = 500;
// This is where the usernames and their connections will be held
readonly Dictionary<string, ServerUserConnection> userToConnections = new Dictionary<string, ServerUserConnection>();
readonly TcpListener listener;
public static void Main()
{
// Constructor for the ChatServer
Server server = new Server();
while(true)
{
Thread.Sleep(1); // Temp to keep alive
}
}
/// <summary>
/// Listens for data from clients
/// </summary>
public Server()
{
listener = TcpListener.Create(PORT);
listener.Start();
WaitForConnections();
}
/// <summary>
/// Begins an asynchronous operation to accept an incoming connection attempt
/// </summary>
private void WaitForConnections()
{
listener.BeginAcceptTcpClient(OnConnect, null);
}
/// <summary>
/// This method is executed asynchronously
/// Connects the client to the server
/// Broadcasts the user to client to be displayed on the chatform
/// Then waits for another connection to be established
/// </summary>
/// <param name="ar"></param>
void OnConnect(IAsyncResult ar)
{
//Asynchronously accepts an incoming connection attempt and creates a new TcpClient to handle remote host communication.
TcpClient client = listener.EndAcceptTcpClient(ar);
Console.WriteLine("Connected");
ReceiveUser(client);
BroadcastUserList();
WaitForConnections();
}
/// <summary>
/// Connects a user to the server and adds them to the dictionary userToConnections
/// </summary>
/// <param name="client"></param>
public void ReceiveUser(TcpClient client)
{
ServerUserConnection connection = new ServerUserConnection(this, client); // Constructor
userToConnections.Add(connection.userName, connection);
}
/// <summary>
/// For each user that is connected append the userList to include that user
/// TODO Do not need to keep a running list of users; send the user over then throw it away
/// </summary>
void BroadcastUserList()
{
string userList = "";
foreach(var connection in userToConnections)
{
userList += $"{connection.Value.userName},";
}
SendMsgToAll(MessageType.UserList, null, userList);
}
/// <summary>
/// Pushes out messages to the connected clients
/// </summary>
/// <param name="type"></param>
/// <param name="user"></param>
/// <param name="message"></param>
public void SendMsgToAll(MessageType type, ServerUserConnection user, string message)
{
Console.WriteLine($"{user?.userName}: {message}");
foreach(var connection in userToConnections)
{
Console.WriteLine($"Sending to {connection.Value.userName}");
Utils.SendInformation(type, connection.Value.stream, message);
}
}
}
}
Here is the ServerUserConnection.cs: I am having trouble understanding how the inheritance here works and what the base keyword does.
namespace Server
{
public class ServerUserConnection : UserConnection
{
readonly Server server;
/// <summary>
/// Facilitates connection
/// </summary>
/// <param name="server"></param>
/// <param name="client"></param>
public ServerUserConnection(Server server, TcpClient client) : base(client, GetUsername(client)) // Inherits from UserConnection()
{
this.server = server;
}
private static string GetUsername(TcpClient client)
{
NetworkStream stream = client.GetStream();
if(stream.CanRead)
{
// Receives infromation from the stream, determines MessageType, and returns username
string userName = Utils.ReceiveInformation(stream, client, out MessageType type);
Console.WriteLine(userName);
return userName;
}
return null;
}
/// <summary>
///
/// </summary>
/// <param name="type"></param>
/// <param name="message"></param>
protected override void OnRead(MessageType type, string message)
{
if(type != MessageType.ChatMessage)
{
return;
}
server.SendMsgToAll(MessageType.ChatMessage, this, $"{userName} {message}");
}
}
}
Here is the Client Code: Client.cs
namespace Client
{
public class ChatClient
{
private const int PORT = 500;
TcpClient client = new TcpClient();
public ChatForm chatForm;
public ClientUserConnection userConnection;
string data;
[STAThread]
public static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
var client = new ChatClient();
var form = new ConnectForm(client);
Application.Run(form);
}
/// <summary>
/// This is called when the ConnectForm btnSubmit is pressed.
/// </summary>
/// <param name="ipAddress"></param>
/// <param name="userName"></param>
public void ConnectToServer(string ipAddress, string userName)
{
client.Connect(ipAddress, PORT);
SendUserName(userName);
}
/// <summary>
/// Sends user to the server
/// </summary>
public void SendUserName(string user)
{
userConnection = new ClientUserConnection(client, this, user);
Utils.SendInformation(MessageType.Connect, client.GetStream(), user);
}
/// <summary>
/// Sends a message to the server
/// </summary>
/// <param name="msg"></param>
public void SendMessage(string msg)
{
Utils.SendInformation(MessageType.ChatMessage, userConnection.stream, msg);
}
}
}
Here is the ClientUserConnection.cs: Is there a way to refactor or optimize this so that instead of keeping a running list of messages just send the message over and throw it away? Again, the same question about inheritance.
public class ClientUserConnection : UserConnection
{
public readonly Client.ChatClient chatClient;
public string message = "";
public string userListText;
/// <summary>
///
/// </summary>
/// <param name="client"></param>
/// <param name="chatClient"></param>
/// <param name="userName"></param>
public ClientUserConnection(TcpClient client, Client.ChatClient chatClient, string userName) : base(client, userName) // Inherits from UserConnection()
{
this.chatClient = chatClient;
}
/// <summary>
/// When the data is reads determine what kind of message it is
/// Parse/split out the message and user; display only relevant data
/// TODO Do not need to keep a running list of messages; send the message over then throw it away
/// </summary>
/// <param name="type"></param>
/// <param name="message"></param>
protected override void OnRead(MessageType type, string message)
{
if(type == MessageType.ChatMessage)
{
int iSpace = message.IndexOf(" ");
if(iSpace < 0)
{
// if error
return;
}
string from = message.Substring(0, iSpace);
string chatMessage = message.Substring(iSpace + 1, message.Length - iSpace - 1);
this.message += $"[{from}]: {chatMessage}{Environment.NewLine}";
}
else if(type == MessageType.UserList)
{
string[] userList = message.Split(',');
string userListText = "";
for(int i = 0; i < userList.Length; i++)
{
userListText += $"{userList[i]}{Environment.NewLine}";
}
this.userListText = userListText;
}
}
}
There are also three files within a class library that are used within this project:
This is the MessageType.cs:
public enum MessageType
{
Connect, UserList, ChatMessage
}
This is the UserConnection.cs: I still need to deal with disconnecting users. If one of the chat forms is closed, it crashes the application.
public abstract class UserConnection
{
public readonly TcpClient client;
public readonly NetworkStream stream;
public readonly string userName;
byte[] data;
/// <summary>
///
/// </summary>
/// <param name="client"></param>
/// <param name="userName"></param>
public UserConnection(TcpClient client, string userName)
{
this.client = client;
this.userName = userName;
stream = client.GetStream();
data = new byte[client.ReceiveBufferSize];
WaitForData();
}
/// <summary>
///
/// </summary>
private void WaitForData()
{
Console.WriteLine("Wait");
stream.BeginRead(data, 0, data.Length, OnReadData, null);
}
/// <summary>
/// SocketException: An existing connection was forcibly closed by the remote host
/// </summary>
/// <param name="ar"></param>
void OnReadData(IAsyncResult ar)
{
Console.WriteLine("Read");
int result = stream.EndRead(ar); // TODO disconnect & error handling
Console.WriteLine("Read done");
if(result <= 0)
{
Console.WriteLine("Error reading");
return;
}
string message = Utils.ReceiveInformation(data, result, out MessageType type);
OnRead(type, message);
WaitForData();
}
/// <summary>
///
/// </summary>
/// <param name="type"></param>
/// <param name="message"></param>
protected abstract void OnRead(MessageType type, string message);
}
This is the Utils.cs: I am having trouble understanding how there are two methods called ReceiveInformation() and how they interact with each other
public class Utils
{
/// <summary>
///
/// </summary>
/// <param name="stream"></param>
/// <param name="connection"></param>
/// <param name="type"></param>
/// <returns></returns>
public static string ReceiveInformation(NetworkStream stream, TcpClient connection, out MessageType type)
{
byte[] bytes = new byte[connection.ReceiveBufferSize];
int length = stream.Read(bytes, 0, bytes.Length);
return ReceiveInformation(bytes, length, out type);
}
/// <summary>
///
/// </summary>
/// <param name="bytes"></param>
/// <param name="length"></param>
/// <param name="type"></param>
/// <returns></returns>
public static string ReceiveInformation(byte[] bytes, int length, out MessageType type)
{
string data = Encoding.ASCII.GetString(bytes, 0, length);
int iSpace = data.IndexOf(' ');
if(iSpace < 0)
{
// TODO
}
string typeString = data.Substring(0, iSpace);
type = (MessageType)Enum.Parse(typeof(MessageType), typeString);
string message = data.Substring(iSpace + 1, data.Length - iSpace - 1);
return message;
}
/// <summary>
///
/// </summary>
/// <param name="type"></param>
/// <param name="stream"></param>
/// <param name="message"></param>
public static void SendInformation(MessageType type, NetworkStream stream, string message)
{
Byte[] sendBytes = Encoding.UTF8.GetBytes($"{type} {message}");
stream.Write(sendBytes, 0, sendBytes.Length);
}
}

how to create a text file in c# using visual studio?

I have been trying to add a Write text file section to this project but i keep getting told that lots of things 'dont exist in the current context'.
The text tile is meant to be created my documents showing 'First line,new line 1, new line 2'
This should work alongside the kinect sample.
I am sorry that i am very new to this and may be doing it completely wrong.
// --------------------------------------------------------------------------------------------------------------------
// <copyright file="MainWindow.xaml.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// --------------------------------------------------------------------------------------------------------------------
namespace Microsoft.Samples.Kinect.HDFaceBasics
{
using System;
using System.ComponentModel;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Media3D;
using Microsoft.Kinect;
using Microsoft.Kinect.Face;
using System.IO;
/// <summary>
/// Main Window
/// </summary>
public partial class MainWindow : Window, INotifyPropertyChanged, IDisposable
{
// Create a string array with the lines of text
string text = "First line" + Environment.NewLine;
// Set a variable to the My Documents path.
string mydocpath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
// Write the text to a new file named "WriteFile.txt".
File.WriteAllText(mydocpath + #"\WriteFile.txt", text);
// Create a string array with the additional lines of text
string[] lines = { "New line 1", "New line 2" };
// Append new lines of text to the file
File.AppendAllLines(mydocpath + #"\WriteFile.txt", lines);
/// <summary>
/// Currently used KinectSensor
/// </summary>
private KinectSensor sensor = null;
/// <summary>
/// Body frame source to get a BodyFrameReader
/// </summary>
private BodyFrameSource bodySource = null;
/// <summary>
/// Body frame reader to get body frames
/// </summary>
private BodyFrameReader bodyReader = null;
/// <summary>
/// HighDefinitionFaceFrameSource to get a reader and a builder from.
/// Also to set the currently tracked user id to get High Definition Face Frames of
/// </summary>
private HighDefinitionFaceFrameSource highDefinitionFaceFrameSource = null;
/// <summary>
/// HighDefinitionFaceFrameReader to read HighDefinitionFaceFrame to get FaceAlignment
/// </summary>
private HighDefinitionFaceFrameReader highDefinitionFaceFrameReader = null;
/// <summary>
/// FaceAlignment is the result of tracking a face, it has face animations location and orientation
/// </summary>
private FaceAlignment currentFaceAlignment = null;
/// <summary>
/// FaceModel is a result of capturing a face
/// </summary>
private FaceModel currentFaceModel = null;
/// <summary>
/// FaceModelBuilder is used to produce a FaceModel
/// </summary>
private FaceModelBuilder faceModelBuilder = null;
/// <summary>
/// The currently tracked body
/// </summary>
private Body currentTrackedBody = null;
/// <summary>
/// The currently tracked body
/// </summary>
private ulong currentTrackingId = 0;
/// <summary>
/// Gets or sets the current tracked user id
/// </summary>
private string currentBuilderStatus = string.Empty;
/// <summary>
/// Gets or sets the current status text to display
/// </summary>
private string statusText = "Ready To Start Capture";
/// <summary>
/// Initializes a new instance of the MainWindow class.
/// </summary>
public MainWindow()
{
this.InitializeComponent();
this.DataContext = this;
}
/// <summary>
/// INotifyPropertyChangedPropertyChanged event to allow window controls to bind to changeable data
/// </summary>
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// Gets or sets the current status text to display
/// </summary>
public string StatusText
{
get
{
return this.statusText;
}
set
{
if (this.statusText != value)
{
this.statusText = value;
// notify any bound elements that the text has changed
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs("StatusText"));
}
}
}
}
/// <summary>
/// Gets or sets the current tracked user id
/// </summary>
private ulong CurrentTrackingId
{
get
{
return this.currentTrackingId;
}
set
{
this.currentTrackingId = value;
this.StatusText = this.MakeStatusText();
}
}
/// <summary>
/// Gets or sets the current Face Builder instructions to user
/// </summary>
private string CurrentBuilderStatus
{
get
{
return this.currentBuilderStatus;
}
set
{
this.currentBuilderStatus = value;
this.StatusText = this.MakeStatusText();
}
}
/// <summary>
/// Called when disposed of
/// </summary>
public void Dispose()
{
this.Dispose(true);
GC.SuppressFinalize(this);
}
/// <summary>
/// Dispose based on whether or not managed or native resources should be freed
/// </summary>
/// <param name="disposing">Set to true to free both native and managed resources, false otherwise</param>
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
if (this.currentFaceModel != null)
{
this.currentFaceModel.Dispose();
this.currentFaceModel = null;
}
}
}
/// <summary>
/// Returns the length of a vector from origin
/// </summary>
/// <param name="point">Point in space to find it's distance from origin</param>
/// <returns>Distance from origin</returns>
private static double VectorLength(CameraSpacePoint point)
{
var result = Math.Pow(point.X, 2) + Math.Pow(point.Y, 2) + Math.Pow(point.Z, 2);
result = Math.Sqrt(result);
return result;
}
/// <summary>
/// Finds the closest body from the sensor if any
/// </summary>
/// <param name="bodyFrame">A body frame</param>
/// <returns>Closest body, null of none</returns>
private static Body FindClosestBody(BodyFrame bodyFrame)
{
Body result = null;
double closestBodyDistance = double.MaxValue;
Body[] bodies = new Body[bodyFrame.BodyCount];
bodyFrame.GetAndRefreshBodyData(bodies);
foreach (var body in bodies)
{
if (body.IsTracked)
{
var currentLocation = body.Joints[JointType.SpineBase].Position;
var currentDistance = VectorLength(currentLocation);
if (result == null || currentDistance < closestBodyDistance)
{
result = body;
closestBodyDistance = currentDistance;
}
}
}
return result;
}
/// <summary>
/// Find if there is a body tracked with the given trackingId
/// </summary>
/// <param name="bodyFrame">A body frame</param>
/// <param name="trackingId">The tracking Id</param>
/// <returns>The body object, null of none</returns>
private static Body FindBodyWithTrackingId(BodyFrame bodyFrame, ulong trackingId)
{
Body result = null;
Body[] bodies = new Body[bodyFrame.BodyCount];
bodyFrame.GetAndRefreshBodyData(bodies);
foreach (var body in bodies)
{
if (body.IsTracked)
{
if (body.TrackingId == trackingId)
{
result = body;
break;
}
}
}
return result;
}
/// <summary>
/// Gets the current collection status
/// </summary>
/// <param name="status">Status value</param>
/// <returns>Status value as text</returns>
private static string GetCollectionStatusText(FaceModelBuilderCollectionStatus status)
{
string res = string.Empty;
if ((status & FaceModelBuilderCollectionStatus.FrontViewFramesNeeded) != 0)
{
res = "FrontViewFramesNeeded";
return res;
}
if ((status & FaceModelBuilderCollectionStatus.LeftViewsNeeded) != 0)
{
res = "LeftViewsNeeded";
return res;
}
if ((status & FaceModelBuilderCollectionStatus.RightViewsNeeded) != 0)
{
res = "RightViewsNeeded";
return res;
}
if ((status & FaceModelBuilderCollectionStatus.TiltedUpViewsNeeded) != 0)
{
res = "TiltedUpViewsNeeded";
return res;
}
if ((status & FaceModelBuilderCollectionStatus.Complete) != 0)
{
res = "Complete";
return res;
}
if ((status & FaceModelBuilderCollectionStatus.MoreFramesNeeded) != 0)
{
res = "TiltedUpViewsNeeded";
return res;
}
return res;
}
/// <summary>
/// Helper function to format a status message
/// </summary>
/// <returns>Status text</returns>
private string MakeStatusText()
{
string status = string.Format(System.Globalization.CultureInfo.CurrentCulture, "Builder Status: {0}, Current Tracking ID: {1}", this.CurrentBuilderStatus, this.CurrentTrackingId);
return status;
}
/// <summary>
/// Fires when Window is Loaded
/// </summary>
/// <param name="sender">object sending the event</param>
/// <param name="e">event arguments</param>
private void Window_Loaded(object sender, RoutedEventArgs e)
{
this.InitializeHDFace();
}
/// <summary>
/// Initialize Kinect object
/// </summary>
private void InitializeHDFace()
{
this.CurrentBuilderStatus = "Ready To Start Capture";
this.sensor = KinectSensor.GetDefault();
this.bodySource = this.sensor.BodyFrameSource;
this.bodyReader = this.bodySource.OpenReader();
this.bodyReader.FrameArrived += this.BodyReader_FrameArrived;
this.highDefinitionFaceFrameSource = new HighDefinitionFaceFrameSource(this.sensor);
this.highDefinitionFaceFrameSource.TrackingIdLost += this.HdFaceSource_TrackingIdLost;
this.highDefinitionFaceFrameReader = this.highDefinitionFaceFrameSource.OpenReader();
this.highDefinitionFaceFrameReader.FrameArrived += this.HdFaceReader_FrameArrived;
this.currentFaceModel = new FaceModel();
this.currentFaceAlignment = new FaceAlignment();
this.InitializeMesh();
this.UpdateMesh();
this.sensor.Open();
}
/// <summary>
/// Initializes a 3D mesh to deform every frame
/// </summary>
private void InitializeMesh()
{
var vertices = this.currentFaceModel.CalculateVerticesForAlignment(this.currentFaceAlignment);
var triangleIndices = this.currentFaceModel.TriangleIndices;
var indices = new Int32Collection(triangleIndices.Count);
for (int i = 0; i < triangleIndices.Count; i += 3)
{
uint index01 = triangleIndices[i];
uint index02 = triangleIndices[i + 1];
uint index03 = triangleIndices[i + 2];
indices.Add((int)index03);
indices.Add((int)index02);
indices.Add((int)index01);
}
this.theGeometry.TriangleIndices = indices;
this.theGeometry.Normals = null;
this.theGeometry.Positions = new Point3DCollection();
this.theGeometry.TextureCoordinates = new PointCollection();
foreach (var vert in vertices)
{
this.theGeometry.Positions.Add(new Point3D(vert.X, vert.Y, -vert.Z));
this.theGeometry.TextureCoordinates.Add(new Point());
}
}
/// <summary>
/// Sends the new deformed mesh to be drawn
/// </summary>
private void UpdateMesh()
{
var vertices = this.currentFaceModel.CalculateVerticesForAlignment(this.currentFaceAlignment);
for (int i = 0; i < vertices.Count; i++)
{
var vert = vertices[i];
this.theGeometry.Positions[i] = new Point3D(vert.X, vert.Y, -vert.Z);
}
}
/// <summary>
/// Start a face capture on clicking the button
/// </summary>
/// <param name="sender">object sending the event</param>
/// <param name="e">event arguments</param>
private void StartCapture_Button_Click(object sender, RoutedEventArgs e)
{
this.StartCapture();
}
/// <summary>
/// This event fires when a BodyFrame is ready for consumption
/// </summary>
/// <param name="sender">object sending the event</param>
/// <param name="e">event arguments</param>
private void BodyReader_FrameArrived(object sender, BodyFrameArrivedEventArgs e)
{
this.CheckOnBuilderStatus();
var frameReference = e.FrameReference;
using (var frame = frameReference.AcquireFrame())
{
if (frame == null)
{
// We might miss the chance to acquire the frame, it will be null if it's missed
return;
}
if (this.currentTrackedBody != null)
{
this.currentTrackedBody = FindBodyWithTrackingId(frame, this.CurrentTrackingId);
if (this.currentTrackedBody != null)
{
return;
}
}
Body selectedBody = FindClosestBody(frame);
if (selectedBody == null)
{
return;
}
this.currentTrackedBody = selectedBody;
this.CurrentTrackingId = selectedBody.TrackingId;
this.highDefinitionFaceFrameSource.TrackingId = this.CurrentTrackingId;
}
}
/// <summary>
/// This event is fired when a tracking is lost for a body tracked by HDFace Tracker
/// </summary>
/// <param name="sender">object sending the event</param>
/// <param name="e">event arguments</param>
private void HdFaceSource_TrackingIdLost(object sender, TrackingIdLostEventArgs e)
{
var lostTrackingID = e.TrackingId;
if (this.CurrentTrackingId == lostTrackingID)
{
this.CurrentTrackingId = 0;
this.currentTrackedBody = null;
if (this.faceModelBuilder != null)
{
this.faceModelBuilder.Dispose();
this.faceModelBuilder = null;
}
this.highDefinitionFaceFrameSource.TrackingId = 0;
}
}
/// <summary>
/// This event is fired when a new HDFace frame is ready for consumption
/// </summary>
/// <param name="sender">object sending the event</param>
/// <param name="e">event arguments</param>
private void HdFaceReader_FrameArrived(object sender, HighDefinitionFaceFrameArrivedEventArgs e)
{
using (var frame = e.FrameReference.AcquireFrame())
{
// We might miss the chance to acquire the frame; it will be null if it's missed.
// Also ignore this frame if face tracking failed.
if (frame == null || !frame.IsFaceTracked)
{
return;
}
frame.GetAndRefreshFaceAlignmentResult(this.currentFaceAlignment);
this.UpdateMesh();
}
}
/// <summary>
/// Start a face capture operation
/// </summary>
private void StartCapture()
{
this.StopFaceCapture();
this.faceModelBuilder = null;
this.faceModelBuilder = this.highDefinitionFaceFrameSource.OpenModelBuilder(FaceModelBuilderAttributes.None);
this.faceModelBuilder.BeginFaceDataCollection();
this.faceModelBuilder.CollectionCompleted += this.HdFaceBuilder_CollectionCompleted;
}
/// <summary>
/// Cancel the current face capture operation
/// </summary>
private void StopFaceCapture()
{
if (this.faceModelBuilder != null)
{
this.faceModelBuilder.Dispose();
this.faceModelBuilder = null;
}
}
/// <summary>
/// This event fires when the face capture operation is completed
/// </summary>
/// <param name="sender">object sending the event</param>
/// <param name="e">event arguments</param>
private void HdFaceBuilder_CollectionCompleted(object sender, FaceModelBuilderCollectionCompletedEventArgs e)
{
var modelData = e.ModelData;
this.currentFaceModel = modelData.ProduceFaceModel();
this.faceModelBuilder.Dispose();
this.faceModelBuilder = null;
this.CurrentBuilderStatus = "Capture Complete";
}
/// <summary>
/// Check the face model builder status
/// </summary>
private void CheckOnBuilderStatus()
{
if (this.faceModelBuilder == null)
{
return;
}
string newStatus = string.Empty;
var captureStatus = this.faceModelBuilder.CaptureStatus;
newStatus += captureStatus.ToString();
var collectionStatus = this.faceModelBuilder.CollectionStatus;
newStatus += ", " + GetCollectionStatusText(collectionStatus);
this.CurrentBuilderStatus = newStatus;
}
}
}

create a method that you can call that will allow you to create as well as append to the file
private static void WriteAndOrAppendText(string path, string strText)
{
using (StreamWriter fileStream = new StreamWriter(path, true))
{
fileStream.WriteLine(strText);
fileStream.Flush();
fileStream.Close();
}
}
// Set a variable to the My Documents path.
string mydocpath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
// Write the text to a new file named "WriteFile.txt".
WriteAndOrAppendText(mydocpath + #"\WriteFile.txt", text);
string[] lines = { "New line 1", "New line 2" };
WriteAndOrAppendText(mydocpath , string.Join(",", lines.ToArray()));

Wpf application on .NET 4.5 to .NET 4.0

I'm in face on the following problem: An application developed on Microsoft Visual Studio 2013 in .NET 4.5, needs to work in Window XP Platforms. I'm rebuild the software using .NET 4.0 and make some modifications to add compatibility, but when i click in a button the app crash and don't show a clear error message and the Trace resource don't log anything. On application start i had a little window that ask user to put your name, and this feature works fine. Anybody have any suggestion of what can i do ?
EDIT 1:
The follow code is the root of problems, this code was compiled using .NET 4.0:
SerialManager.cs
using System;
using System.Windows;
using TestSat;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.IO.Ports;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Threading;
using System.Text.RegularExpressions;
using System.Diagnostics;
namespace TestSat.DataModel
{
/// <summary>
///
/// </summary>
public class SerialManager : INotifyPropertyChanged
{
#region Events
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
///
/// </summary>
/// <param name="propertyName"></param>
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
/* [AttributeUsage(AttributeTargets.Parameter, AllowMultiple = false, Inherited = true)]
public sealed class CallerMemberNameAttribute : Attribute
{
}*/
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="field"></param>
/// <param name="value"></param>
/// <param name="propertyName"></param>
/// <returns></returns>
protected bool SetField<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
{
if (EqualityComparer<T>.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(propertyName);
return true;
}
#endregion
#region Private Fields
private static SerialPort PortaSerial;
private ObservableCollection<String> mPorts;
private String mSelectedPort;
private int mBaudRate = 115200;
private int mDataBits = 8;
#endregion
#region Public Fields
public StringBuilder logText;
#endregion
#region Properties
/// <summary>
///
/// </summary>
public ObservableCollection<String> COMPorts
{
get { return mPorts; }
set { SetField(ref mPorts, value); }
}
/// <summary>
///
/// </summary>
public String TextoLog
{
get { return logText.ToString(); }
set
{
if (logText.Length >= logText.MaxCapacity)
{
logText.Clear();;
logText.Append(value);
}
else
{
logText.Append(value);
//MainWindow.last = value;
}
OnPropertyChanged("TextoLog");
}
}
/// <summary>
///
/// </summary>
public String SelectedPort
{
get { return mSelectedPort; }
set {SetField(ref mSelectedPort, value); }
}
#endregion
#region Construtors
/// <summary>
///
/// </summary>
public SerialManager()
{
InitComponents();
}
/// <summary>
///
/// </summary>
private void InitComponents()
{
RefreshPorts();
/*Initialize the log variable*/
logText = new StringBuilder();
/* Update selected port */
SelectedPort = COMPorts.Count > 0 ? COMPorts[0] : "";
}
#endregion
#region Public Methods
/// <summary>
///
/// </summary>
public void RefreshPorts()
{
// Update ports
string[] pPorts = SerialPort.GetPortNames();
// Sort alphabetically
Array.Sort(pPorts);
// Sort by string length
Array.Sort(pPorts, (x, y) => x.Length.CompareTo(y.Length));
// Create collection
COMPorts = new ObservableCollection<string>(pPorts);
}
/// <summary>
///
/// </summary>
/// <param name="mSelectedPort"></param>
public void ConnectSerial(String mSelectedPort)
{
PortaSerial = new SerialPort();
PortaSerial.PortName = mSelectedPort;
PortaSerial.BaudRate = mBaudRate;
PortaSerial.Parity = Parity.None;
PortaSerial.DataBits = mDataBits;
PortaSerial.StopBits = StopBits.One;
PortaSerial.Handshake = Handshake.None;
PortaSerial.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandler);
Trace.WriteLine("DataReceived definida");
try
{
PortaSerial.Open();
}
catch (SystemException)
{
MessageBox.Show("A porta serial esta sendo usada em outra aplicação.", "Erro", MessageBoxButton.OK);
throw new SystemException();
}
}
/// <summary>
///
/// </summary>
public void DesconnectSerial()
{
if (PortaSerial.IsOpen)
{
PortaSerial.Close();
}
}
/// <summary>
///
/// </summary>
public void writeSerial(String text)
{
if (PortaSerial.IsOpen)
{
if (text.Length > 0)
{
/* char[] array = text.ToCharArray(0,text.Length);
foreach(char ch in array)
{
PortaSerial.Write(ch.ToString());
Thread.Sleep(50);
}*/
PortaSerial.WriteLine(text);
}
else
{
PortaSerial.WriteLine("");
}
}
else
{
MessageBox.Show("Porta serial não esta aberta.", "Erro", MessageBoxButton.OK);
Console.WriteLine("Porta serial não esta aberta");
}
}
/// <summary>
///
/// </summary>
public bool IsOpen()
{
return PortaSerial.IsOpen;
}
/// <summary>
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void DataReceivedHandler(object sender, SerialDataReceivedEventArgs e)
{
MainWindow.StartRawData = true;
SerialPort sp = (SerialPort)sender;
string indata = sp.ReadExisting();
TextoLog = indata;
/*Omited code only logical operation*/
}
#endregion
}
}
If i don't do any instance or reference to serial port the applications don't crashes. Exist a way to force this part of code compiled by .NET 3.5? Or exist another suggestion of solution for this problem?

The solution i found at http://blogs.msdn.com/b/bclteam/p/asynctargetingpackkb.asp , Issue 8. Installing the .NET 4.0 update the problems don't occured anymore.

WatiN unreliable for repeated downloads?

WatiN seems to not handle repeated download dialogs consistently:
foreach (string file in lstFiles)
{
// continue if no download link
if (!ie.Element([search criteria]).Exists) continue;
var btnDownload = ie.Element([search criteria]);
string fullFilename = workingDir + "\\" + file;
FileDownloadHandler download = new FileDownloadHandler(fullFilename);
using (new UseDialogOnce(ie.DialogWatcher, download))
{
btnDownload.ClickNoWait();
download.WaitUntilFileDownloadDialogIsHandled(30);
download.WaitUntilDownloadCompleted(150);
ie.RemoveDialogHandler(download);
}
}
Basically, I loop through a list of filenames that I expect to be available and click the download button. This usually works, but after so many downloads (it varies, sometimes everything that's available downloads, sometimes nothing) it will hang while waiting to handle the dialog. The button's identified correctly, the download dialog appears, it just isn't detected and handled. It isn't site-specific as similar methods on other sites are also met with variable success. Anyone encounter this before and know of a resolution?
edit: Repeated downloads do not work whatsoever in Server 2008. In Win7, this happens randomly after one or more successful repeated downloads.

The problem appears because IE File Download Dialog consist of 2 windows. WatiN DialogWatcher gets all the system windows and tries to handle them in foreach loop. After handling first correct dialog window DialogWatcher gets the next window wich has the same properties and is a valid Download Dialog. DialogWatcher starts waiting until this window is visible but it closes immediately after previos window is handled.
My solution is to return from foreach loop after any dialog is handled:
#region WatiN Copyright (C) 2006-2011 Jeroen van Menen
//Copyright 2006-2011 Jeroen van Menen
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#endregion Copyright
using System;
using System.Collections.Generic;
using System.Threading;
using WatiN.Core.Exceptions;
using WatiN.Core.Interfaces;
using WatiN.Core.Logging;
using WatiN.Core.Native.InternetExplorer;
using WatiN.Core.Native.Windows;
using WatiN.Core.UtilityClasses;
namespace WatiN.Core.DialogHandlers
{
/// <summary>
/// This class handles alert/popup dialogs. Every second it checks if a dialog
/// is shown. If so, it stores it's message in the alertQueue and closses the dialog
/// by clicking the close button in the title bar.
/// </summary>
public class DialogWatcher : IDisposable
{
private static IList<DialogWatcher> dialogWatchers = new List<DialogWatcher>();
private bool _keepRunning = true;
private readonly IList<IDialogHandler> _handlers;
private readonly Thread _watcherThread;
private bool _closeUnhandledDialogs = Settings.AutoCloseDialogs;
public Window MainWindow { get; private set; }
/// <summary>
/// Gets the dialog watcher for the specified (main) internet explorer window.
/// It creates new instance if no dialog watcher for the specified window exists.
/// </summary>
/// <param name="mainWindowHwnd">The (main) internet explorer window.</param>
/// <returns></returns>
public static DialogWatcher GetDialogWatcher(IntPtr mainWindowHwnd)
{
var window = new Window(mainWindowHwnd);
Logger.LogDebug("GetDialogWatcher mainhwnd: " + window.Hwnd + ", " + window.Title);
var toplevelWindow = window.ToplevelWindow;
Logger.LogDebug("GetDialogWatcher mainhwnd: " + toplevelWindow.Hwnd + ", " + toplevelWindow.Title);
CleanupDialogWatcherCache();
var dialogWatcher = GetDialogWatcherFromCache(toplevelWindow);
// If no dialogwatcher exists for the ieprocessid then
// create a new one, store it and return it.
if (dialogWatcher == null)
{
dialogWatcher = new DialogWatcher(toplevelWindow);
dialogWatchers.Add(dialogWatcher);
}
return dialogWatcher;
}
public static DialogWatcher GetDialogWatcherFromCache(Window mainWindow)
{
// Loop through already created dialogwatchers and
// return a dialogWatcher if one exists for the given processid
foreach (var dialogWatcher in dialogWatchers)
{
if (dialogWatcher.MainWindow.Equals(mainWindow))
{
return dialogWatcher;
}
}
return null;
}
public static void CleanupDialogWatcherCache()
{
var cleanedupDialogWatcherCache = new List<DialogWatcher>();
foreach (var dialogWatcher in dialogWatchers)
{
if (!dialogWatcher.IsRunning)
{
dialogWatcher.Dispose();
}
else
{
cleanedupDialogWatcherCache.Add(dialogWatcher);
}
}
dialogWatchers = cleanedupDialogWatcherCache;
}
/// <summary>
/// Initializes a new instance of the <see cref="DialogWatcher"/> class.
/// You are encouraged to use the Factory method <see cref="DialogWatcher.GetDialogWatcherFromCache"/>
/// instead.
/// </summary>
/// <param name="mainWindow">The main window handle of internet explorer.</param>
public DialogWatcher(Window mainWindow)
{
MainWindow = mainWindow;
_handlers = new List<IDialogHandler>();
// Create thread to watch windows
_watcherThread = new Thread(Start);
// Start the thread.
_watcherThread.Start();
}
/// <summary>
/// Increases the reference count of this DialogWatcher instance with 1.
/// </summary>
public void IncreaseReferenceCount()
{
ReferenceCount++;
}
/// <summary>
/// Decreases the reference count of this DialogWatcher instance with 1.
/// When reference count becomes zero, the Dispose method will be
/// automatically called. This method will throw an <see cref="ReferenceCountException"/>
/// if the reference count is zero.
/// </summary>
public void DecreaseReferenceCount()
{
if (ReferenceCount > 0)
{
ReferenceCount--;
}
else
{
throw new ReferenceCountException();
}
if (ReferenceCount == 0)
{
Dispose();
}
}
/// <summary>
/// Adds the specified handler.
/// </summary>
/// <param name="handler">The handler.</param>
public void Add(IDialogHandler handler)
{
lock (this)
{
_handlers.Add(handler);
}
}
/// <summary>
/// Removes the specified handler.
/// </summary>
/// <param name="handler">The handler.</param>
public void Remove(IDialogHandler handler)
{
lock (this)
{
_handlers.Remove(handler);
}
}
/// <summary>
/// Removes all instances that match <paramref name="handler"/>.
/// This method determines equality by calling Object.Equals.
/// </summary>
/// <param name="handler">The object implementing IDialogHandler.</param>
/// <example>
/// If you want to use RemoveAll with your custom dialog handler to
/// remove all instances of your dialog handler from a DialogWatcher instance,
/// you should override the Equals method in your custom dialog handler class
/// like this:
/// <code>
/// public override bool Equals(object obj)
/// {
/// if (obj == null) return false;
///
/// return (obj is YourDialogHandlerClassNameGoesHere);
/// }
/// </code>
/// You could also inherit from <see cref="BaseDialogHandler"/> instead of implementing
/// <see cref="IDialogHandler"/> in your custom dialog handler. <see cref="BaseDialogHandler"/> provides
/// overrides for Equals and GetHashCode that work with RemoveAll.
/// </example>
public void RemoveAll(IDialogHandler handler)
{
while (Contains(handler))
{
Remove(handler);
}
}
/// <summary>
/// Removes all registered dialog handlers.
/// </summary>
public void Clear()
{
lock (this)
{
_handlers.Clear();
}
}
/// <summary>
/// Determines whether this <see cref="DialogWatcher"/> contains the specified dialog handler.
/// </summary>
/// <param name="handler">The dialog handler.</param>
/// <returns>
/// <c>true</c> if [contains] [the specified handler]; otherwise, <c>false</c>.
/// </returns>
public bool Contains(IDialogHandler handler)
{
lock (this)
{
return _handlers.Contains(handler);
}
}
/// <summary>
/// Gets the count of registered dialog handlers.
/// </summary>
/// <value>The count.</value>
public int Count
{
get
{
lock (this)
{
return _handlers.Count;
}
}
}
/// <summary>
/// Gets or sets a value indicating whether unhandled dialogs should be closed automaticaly.
/// The initial value is set to the value of <cref name="Settings.AutoCloseDialogs" />.
/// </summary>
/// <value>
/// <c>true</c> if unhandled dialogs should be closed automaticaly; otherwise, <c>false</c>.
/// </value>
public bool CloseUnhandledDialogs
{
get
{
lock (this)
{
return _closeUnhandledDialogs;
}
}
set
{
lock (this)
{
_closeUnhandledDialogs = value;
}
}
}
/// <summary>
/// Gets the (main) internet explorer window handle this dialog watcher watches.
/// </summary>
/// <value>The process id.</value>
public IntPtr MainWindowHwnd
{
get { return MainWindow.Hwnd; }
}
/// <summary>
/// Called by the constructor to start watching popups
/// on a separate thread.
/// </summary>
private void Start()
{
while (_keepRunning)
{
if (MainWindow.Exists())
{
var winEnumerator = new WindowsEnumerator();
var windows = winEnumerator.GetWindows(win => true);
foreach (var window in windows)
{
if (!_keepRunning) return;
if(HandleWindow(window))
break;
}
// Keep DialogWatcher responsive during 1 second sleep period
var count = 0;
while (_keepRunning && count < 5)
{
Thread.Sleep(200);
count++;
}
}
else
{
_keepRunning = false;
}
}
}
public bool IsRunning
{
get { return _watcherThread.IsAlive; }
}
public int ReferenceCount { get; private set; }
/// <summary>
/// Get the last stored exception thrown by a dialog handler while
/// calling the <see cref="IDialogHandler.HandleDialog"/> method of the
/// dialog handler.
/// </summary>
/// <value>The last exception.</value>
public Exception LastException { get; private set; }
/// <summary>
/// If the window is a dialog and visible, it will be passed to
/// the registered dialog handlers. I none if these can handle
/// it, it will be closed if <see cref="CloseUnhandledDialogs"/>
/// is <c>true</c>.
/// </summary>
/// <param name="window">The window.</param>
/// <returns>
/// <c>true</c> if dialog is handled by one of handlers; otherwise, <c>false</c>.
/// </returns>
public bool HandleWindow(Window window)
{
if (!window.IsDialog()) return false;
if (!HasDialogSameProcessNameAsBrowserWindow(window)) return false;
// This is needed otherwise the window Style will return a "wrong" result.
WaitUntilVisibleOrTimeOut(window);
// Lock the thread and see if a handler will handle
// this dialog window
lock (this)
{
foreach (var dialogHandler in _handlers)
{
try
{
if (dialogHandler.CanHandleDialog(window, MainWindow.Hwnd))
{
if (dialogHandler.HandleDialog(window)) return true;
}
}
catch (Exception e)
{
LastException = e;
Logger.LogAction((LogFunction log) => { log("Exception was thrown while DialogWatcher called HandleDialog: {0}",e.ToString()); });
}
}
// If no handler handled the dialog, see if the dialog
// should be closed automatically.
if (!CloseUnhandledDialogs || !MainWindow.Equals(window.ToplevelWindow)) return false;
Logger.LogAction((LogFunction log) => { log("Auto closing dialog with title: '{0}', text: {1}, style: ", window.Title, window.Message, window.StyleInHex); });
window.ForceClose();
}
return false;
}
private bool HasDialogSameProcessNameAsBrowserWindow(Window window)
{
var comparer = new Comparers.StringComparer(window.ProcessName, true);
return comparer.Compare(MainWindow.ProcessName);
}
private static void WaitUntilVisibleOrTimeOut(Window window)
{
// Wait untill window is visible so all properties
// of the window class (like Style and StyleInHex)
// will return valid values.
var tryActionUntilTimeOut = new TryFuncUntilTimeOut(TimeSpan.FromSeconds(Settings.WaitForCompleteTimeOut));
var success = tryActionUntilTimeOut.Try(() => window.Visible);
if (!success)
{
Logger.LogAction((LogFunction log) => { log("Dialog with title '{0}' not visible after {1} seconds.", window.Title, Settings.WaitForCompleteTimeOut); });
}
}
#region IDisposable Members
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or
/// resetting unmanaged resources.
/// </summary>
public void Dispose()
{
lock (this)
{
_keepRunning = false;
}
if (IsRunning)
{
_watcherThread.Join();
}
Clear();
}
#endregion
}
}

My team ran into this as well while automating IE8 with WatiN. The problem seems to be with IE, possibly doing some time consuming house-cleaning. The work-around we ultimately used was to invoke a new instance of IE within the outer loop, disposing of it each iteration and then waiting for 5 seconds for whatever was going on in the background to resolve. It was a hack but got the job done.
foreach (var file in lstFiles)
{
string fullFilename = workingDir + "\\" + file;
using (var browser = new IE(fullFilename))
{
//page manipulations...
FileDownloadHandler download = new FileDownloadHandler(fullFilename);
using (new UseDialogOnce(browser.DialogWatcher, download))
{ //lnkFile.ClickNoWait();
download.WaitUntilFileDownloadDialogIsHandled(15);
download.WaitUntilDownloadCompleted(150);
}
}
Thread.Sleep(5000);
}

Who should log an error/exception

I am trying to figure out the best practices when loggin exceptions.
So far, I am logging every time I catch an exception. But when a lower lever class catches an exception (say, from the database layer), and wraps it in our own application exception - should I also log the original exception there, or should I just let the upper lever class log all the details?
And what about locations where my lower level class decides to throw an exception because of bad input parameters? Should it log the exception there also, or, once again, just let the catching code log it?

Mainly you should avoid logging it in both a lower-level catch and a higher-level catch, as this bloats the log with redundant information (not to mention takes up additional IO resources to write to the log).
If you are looking for general best practice information on exception handling, this link is handy.

You can get away with logging only once at the very top level of your app, as long as your logging code (a) logs the stack trace of an exception, and (b) logs the entire chain of inner exceptions as well.
The Microsoft Exception Handling Application Block takes care of both of those things for you. I guess other logging frameworks would do the same.

In my winform's applications i created some Observer for logging. Observer has subscribers, which can write log somewhere, or process it.
It's look:
public static class LoggingObserver
{
/// <summary>
/// Last getted log message
/// </summary>
public static string LastLog;
/// <summary>
/// Last getted exception
/// </summary>
public static Exception LastException;
/// <summary>
/// List of log's processors
/// </summary>
public static List<BaseLogging> loggings = new List<BaseLogging>();
/// <summary>
/// Get Exception and send for log's processors
/// </summary>
/// <param name="ex">Exception with message</param>
public static void AddLogs(Exception ex)
{
LastException = ex;
LastLog = string.Empty;
foreach (BaseLogging logs in loggings)
{
logs.AddLogs(ex);
}
}
/// <summary>
/// Get message log for log's processors
/// </summary>
/// <param name="str">Message log</param>
public static void AddLogs(string str)
{
LastException = null;
LastLog = str;
foreach (BaseLogging logs in loggings)
{
logs.AddLogs(str);
}
}
/// <summary>
/// Close all processors
/// </summary>
public static void Close()
{
foreach (BaseLogging logs in loggings)
{
logs.Close();
}
}
}
Subscriber's abstract class:
public abstract class BaseLogging
{
/// <summary>
/// Culture (using for date)
/// </summary>
public CultureInfo culture;
/// <summary>
/// Constructor
/// </summary>
/// <param name="culture">Culture</param>
public BaseLogging(CultureInfo culture)
{
this.culture = culture;
}
/// <summary>
/// Add log in log system
/// </summary>
/// <param name="str">message of log</param>
public virtual void AddLogs(string str)
{
DateTime dt = DateTime.Now;
string dts = Convert.ToString(dt, culture.DateTimeFormat);
WriteLine(String.Format("{0} : {1}", dts, str));
}
/// <summary>
/// Add log in log system
/// </summary>
/// <param name="ex">Exception</param>
public virtual void AddLogs(Exception ex)
{
DateTime dt = DateTime.Now;
string dts = Convert.ToString(dt, culture.DateTimeFormat);
WriteException(ex);
}
/// <summary>
/// Write string on log system processor
/// </summary>
/// <param name="str">logs message</param>
protected abstract void WriteLine(string str);
/// <summary>
/// Write string on log system processor
/// </summary>
/// <param name="ex">Exception</param>
protected abstract void WriteException(Exception ex);
/// <summary>
/// Close log system (file, stream, etc...)
/// </summary>
public abstract void Close();
}
And implementation for logging to file:
/// <summary>
/// Logger processor, which write log to some stream
/// </summary>
public class LoggingStream : BaseLogging
{
private Stream stream;
/// <summary>
/// Constructor.
/// </summary>
/// <param name="stream">Initialized stream</param>
/// <param name="culture">Culture of log system</param>
public LoggingStream (Stream stream, CultureInfo culture)
: base(culture)
{
this.stream = stream;
}
/// <summary>
/// Write message log to stream
/// </summary>
/// <param name="str">Message log</param>
protected override void WriteLine(string str)
{
try
{
byte[] bytes;
bytes = Encoding.ASCII.GetBytes(str + "\n");
stream.Write(bytes, 0, bytes.Length);
stream.Flush();
}
catch { }
}
/// <summary>
/// Write Exception to stream
/// </summary>
/// <param name="ex">Log's Exception</param>
protected override void WriteException(Exception ex)
{
DateTime dt = DateTime.Now;
string dts = Convert.ToString(dt, culture.DateTimeFormat);
string message = String.Format("{0} : Exception : {1}", dts, ex.Message);
if (ex.InnerException != null)
{
message = "Error : " + AddInnerEx(ex.InnerException, message);
}
WriteLine(message);
}
/// <summary>
/// Closing stream
/// </summary>
public override void Close()
{
stream.Close();
}
private string AddInnerEx(Exception exception, string message)
{
message += "\nInner Exception : " + exception.Message;
if (exception.InnerException != null)
{
message = AddInnerEx(exception.InnerException, message);
}
return message;
}
}
Using:
//initialization
FileStream FS = new FileStream(LogFilePath, FileMode.Create);
LoggingObserver.loggings.Add(new LoggingStream(FS, Thread.CurrentThread.CurrentCulture));
//write exception
catch (Exception ex) {
LoggingObserver.AddLog(new Exception ("Exception message", ex));
}
//write log
LoggingObserver.AddLog("Just a log");

log where you catch, If you're wrapping then you should. If the lower wrapper doesn't then you have a reason (for debugability) to do so. However don't swallow the exception unless you know its benign or you can handle it.
I'd suggest
try{
.
.
.
} catch(Exception ex){
... log ....
throw;
}
if you need to log and pass the exception on.