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Changing Textbox.text within a method; For loop not looping due to Return

Below is a button, when pressed it calls a function that pings a bunch of IP addresses. If the IP address returns a response, it adds the IP address to the output_networkSearch.Text.
private void button_networkSearch_Click(object sender, RoutedEventArgs e)
{
output_networkSearch.Text = networkSearch(Convert.ToInt32(input_searchLimit.Text));
}
Below isn't the whole method, just the part that I can't get to work. The for loop starts at whatever the last digit on the users default gateway IP address is, and stops at whatever limit they have inputed (1 - 255).
// i is equal to the last digit in the default gateway IP, if it was 192.168.0.1 then i = 1.
for (int i = Convert.ToInt32(splitGatewayIP[3]); i <= searchLimit; i = i + 1)
{
// If the method receieves a ping reply...
if (PingHostSweep(gatewayIPRebuild + i))
{
// Returns 192.168.0. + i + ACTIVE
string response = gatewayIPRebuild + i + " ACTIVE";
return response;
}
else
{
string response = gatewayIPRebuild + i + " CLOSED";
return response;
}
}
This worked on a console application but for a WPF application it seems to run through the loop once and stop due to the return statement.
My idea to work around this would be to remove the Return Response statements and try and access the TextBox (output_networkSearch) directly.
So I would do something like:
for (int i = Convert.ToInt32(splitGatewayIP[3]); i <= searchLimit; i = i + 1)
{
// If the method receieves a ping reply...
if (PingHostSweep(gatewayIPRebuild + i))
{
// Returns 192.168.0. + i + ACTIVE
string response = gatewayIPRebuild + i + " ACTIVE";
output_networkSearch.Text = reponse;
}
else
{
string response = gatewayIPRebuild + i + " CLOSED";
output_networkSearch.Text = reponse;
}
}
HOWEVER, I can't access the textbox within the method for some reason. I've only just started learning C# so I'm not entirely familiar with how it works.
Here's an image of a partially working concept. As you can see the limit is set at 10, so it should ping IP address 1 through 10 and give an ACTIVE or CLOSED response. This did work in my console application version.
WPF version
Console version

This might do the trick for you
List<string> responses = new List<string>();
string response;
for (int i = Convert.ToInt32(splitGatewayIP[3]); i <= searchLimit; i = i + 1)
{
if (PingHostSweep(gatewayIPRebuild + i))
{
response = gatewayIPRebuild + i + " ACTIVE";
}
else
{
response = gatewayIPRebuild + i + " CLOSED";
}
responses.Add(response)
}
Now after the loop the list which is responses would have the list of all the IPs which are active and closed. Like the way you do had in the console Application.

i think you need use threading, there are need many child threading work in backend to scan, when they finish them work then response the result to MainForm, so i write some code hope can help you!
using System.Threading;
using System.Threading.Tasks;
public void Start(string ip)
{
Task.Factory.StartNew(() =>
{
// If the method receieves a ping reply...
string response;
if (PingHostSweep(ip))
{
// Returns 192.168.0. + i + ACTIVE
response = ip + " ACTIVE";
}
else
{
response = ip + " CLOSED";
}
this.Invoke((MethodInvoker)(() => { textBox1.AppendText("\r\n" + response); }));
});
}
private void button1_Click(object sender, EventArgs e)
{
for (int i = 1; i <= 255; i++)
{
Start(String.Format("192.168.100.{0}", i));
}
}

The previous answer was correct (though it didn't touch on a more advanced point that you will ultimately need to learn ... delegation and invocation ... long story ... won't bore you now).
What you wrote distills to this:
// SIDE NOTE: you cannot actually treat an IPv4 address as four "pure" quads (but that's not your question)
var notNecessarilyAHost = splitGatewayIP[3];
var searchStart = Convert.ToInt32(notNecessarilyAHost);
for (var i = searchStart; i <= searchLimit; ++i)
{
if (PingHostSweep(gatewayIPRebuild + i))
{
return $"{gatewayIPRebuild}{i} ACTIVE";
}
else
{
return $"{gatewayIPRebuild}{i} CLOSED";
}
}
...and if you (mentally) step through what you wrote it's fairly straightforward to see that the loop will only ever cycle once. Upon entry to the loop i will be equal to whatever searchStart is. Then you enter the if test. If that test is true, you fall into the true side of the branch (i.e., "...ACTIVE"). Otherwise, you'll drop into the else branch (i.e., "...CLOSED". FROM THERE...
You ALWAYS return. That will exit the loop (and the function that contains it). You will never cycle the loop again. "break" and "return" (and plausibly goto ... but that's for a different day) will ALWAYS exit the current scope (scope being a block of code wrapped by '{' and '}' (be they explicitly or implicitly written).
Following?
The previous answer was correct. It adjusts your code so that the loop adds the string you're composing with each iteration to a list of strings. Then, when you exit the loop (because i reaches searchLimit) that list of strings will contain N many, well, strings. You probably want to return or continue working that.
All that said, you can't (technically you can but you SHOULDN'T) do any of this inside a UI thread. If you do, the UI will block (and become 100% unresponsive to the user) while the loop runs (and the network calls that it makes run), etc.

Simple Chat Client-Server Encryption

I wanted to make a chat client server, very simple, but at the same time very safe, using AES-256bit. I have thought so, tell me if I'm wrong, of course.
The various client enter in a "secure" textbox the passwords (which must be the same everywhere) and in the sending functions (of the client program), clients encrypt messages that I put in another ordinary textbox, using the password and send them to the server; the receiving function always decrypts always using the same key. The server should instead do nothing at the encryption level.
I tried, but I do not know if it doesn't work because of at the code level.
Here's how I modified both the sending and receiving functions on the client: send function
// send the message to the server
private void SendMessage()
{
if (txtMessage.Lines.Length >= 1)
{
byte[] passwordBytes = GetPasswordBytes();
encrypted_message = AES.Encrypt(txtMessage.Text, passwordBytes);
swSender.WriteLine(encrypted_message);
swSender.Flush();
txtMessage.Lines = null;
}
txtMessage.Text = "";
}
receiving function:
private void ReceiveMessages()
{
// Receive the response from the server
srReceiver = new StreamReader(tcpServer.GetStream());
// If the first character of the response is 1, connection was successful
string ConResponse = srReceiver.ReadLine();
// If the first character is a 1, connection was successful
if (ConResponse[0] == '1')
{
// Update the form to tell it we are now connected
this.Invoke(new UpdateLogCallback(this.UpdateLog), new object[] { "Connessione avvenuta con successo!" });
}
else // If the first character is not a 1 (probably a 0), the connection was unsuccessful
{
string Reason = "Non connesso: ";
// Extract the reason out of the response message. The reason starts at the 3rd character
Reason += ConResponse.Substring(2, ConResponse.Length - 2);
// Update the form with the reason why we couldn't connect
this.Invoke(new CloseConnectionCallback(this.CloseConnection), new object[] { Reason });
// Exit the method
return;
}
// While we are successfully connected, read incoming lines from the server
while (Connected == true)
{
try
{
// Show the messages decrypted in the log TextBox
this.Invoke(new UpdateLogCallback(this.MessageUpdateLog), new object[] { srReceiver.ReadLine() });
}
catch
{
try
{
this.Invoke(new UpdateLogCallback(this.UpdateLog), new object[] { srReceiver.ReadLine() });
}
catch { }
}
}
}
// This method is called from a different thread in order to update the log TextBox
private void UpdateLog(string strMessage)
{
txtLog.AppendText(strMessage + "\r\n");
}
//Decrypt the messages incoming from the other client
private void MessageUpdateLog(string strMessage_de)
{
byte[] passwordBytes = GetPasswordBytes();
strMessage_de = AES.Decrypt(strMessage_de, passwordBytes);
// Append text also scrolls the TextBox to the bottom each time
txtLog.AppendText(strMessage_de + "\r\n");
}
not to make the job hard, I thought of exchange encryption passwords (keys) via voice, since it would be a chat room for personal use.

Terminating a function after a specified time

Im working on an EConnect integration Windows form app in C#. Im having a lot of trouble testing my connection string. Basically I give the user the option to change the connection string so I want to be able to test it. As far as I know EConnect doesnt have any built in functions that test the connection so I'm writing a pretty crude function to do it myself. Just for everyones information the connection string consists of a server name that the GP databases are located on and a database name.
The particulars of the actual test function I dont think are that important but the main issue is within that function I call an eConnect method called getEntity, this method uses the connection string and if the connection string is right it will pull information. If the database name is wrong the getEntity method will return an eConnect exception which is easy enough to catch, however if the server name is wrong the getEntity method will just spin and my app gets stuck.
Im trying to write something where I can possibly run my test function asynchronously and simultaneously check for a timeout or the econnect exception. This is where I get stuck, I cant for the life of me get it to work. Here is the first thing I tried (this is in my TestConnection method):
task = Task.Factory.StartNew(() => requester.GetEntity(GPCongfigSettings.GPConnectionString, myXmlDocument.OuterXml), token);
try
{
if (!task.Wait(timeOut, token))
{
Console.WriteLine("The server name is incorrect - task timed out");
return false;
}
}
catch (ThreadInterruptedException)
{
return false;
}
catch (AggregateException ae)
{
ae.Handle((x) =>
{
if (x is eConnectException) // This we know how to handle.
{
Console.WriteLine("Incorrect Database Name! -- " + x.Message);
return false;
}
return false; // Let anything else stop the application.
});
}
This would catch the cases where the server was wrong and if my econnect method would just time out. But it never caught the eConnect exception, Visual Studio would break the app and tell me I had an unhandled exception.
Here is what Im trying now, this is the full class I have for my form. Here I'm trying to use IAsyncResult and using a WaitHandle to check to see if the function completes or times out. This seems to work sometimes, it works for a correct string and for when the database is wrong, and sometimes it works for when the server is wrong, but once I test for a wrong server name it doesnt work correctly for anything else anymore. Is there something I'm missing or is there a better way to run the getentity method in TestGPConnection and check to see if it hasnt completed after a certain time period and if it hasnt kill that method and have the user reenter a server name?
public partial class UpdateGPConnection : Form
{
Task task;
AsyncCallback cb;
public delegate string startProcessToCall();
startProcessToCall sp2c;
public UpdateGPConnection()
{
InitializeComponent();
this.txtDatasourceName.Text = ConfigurationManager.AppSettings.Get("GPDataServer");
this.txtDatabaseName.Text = ConfigurationManager.AppSettings.Get("GPDatabase");
cb = new AsyncCallback(startProcessCallback);
sp2c = new startProcessToCall(TestGPConnection);
}
public void startProcessCallback(IAsyncResult iar)
{
startProcessToCall mc = (startProcessToCall)iar.AsyncState;
bool result = mc.EndInvoke(iar);
Console.WriteLine("Function value = {0}", result);
}
private void btnUpdate_Click(object sender, EventArgs e)
{
var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
config.AppSettings.Settings["GPDataServer"].Value = txtDatasourceName.Text.ToUpper();
config.AppSettings.Settings["GPDatabase"].Value = txtDatabaseName.Text.ToUpper();
config.Save(ConfigurationSaveMode.Modified);
ConfigurationManager.RefreshSection("appSettings");
GPCongfigSettings.GPConnectionString = #"data source=" + txtDatasourceName.Text.ToUpper() + ";initial catalog=" + txtDatabaseName.Text.ToUpper() + ";integrated security=SSPI;persist security info=False;packet size=4096";
IAsyncResult asyncResult = null;
asyncResult = sp2c.BeginInvoke(cb, null);
timer1.Enabled = true;
Thread.Sleep(0);
bool test = asyncResult.AsyncWaitHandle.WaitOne(15000);
if (test)
{
try
{
string testResult = sp2c.EndInvoke(asyncResult);
}
catch (Exception exc)
{
Console.WriteLine(exc.Message);
}
}
bool result = asyncResult.IsCompleted;
asyncResult.AsyncWaitHandle.Close();
this.Close();
}
public string TestGPConnection()
{
eConnectMethods requester = new eConnectMethods();
try
{
// Create an eConnect document type object
eConnectType myEConnectType = new eConnectType();
// Create a RQeConnectOutType schema object
RQeConnectOutType myReqType = new RQeConnectOutType();
// Create an eConnectOut XML node object
eConnectOut myeConnectOut = new eConnectOut();
// Populate the eConnectOut XML node elements
myeConnectOut.ACTION = 1;
myeConnectOut.DOCTYPE = "GL_Accounts";
myeConnectOut.OUTPUTTYPE = 2;
myeConnectOut.FORLIST = 1;
myeConnectOut.WhereClause = "(ACTNUMST = '99-9999-99-999')";
// Add the eConnectOut XML node object to the RQeConnectOutType schema object
myReqType.eConnectOut = myeConnectOut;
// Add the RQeConnectOutType schema object to the eConnect document object
RQeConnectOutType[] myReqOutType = { myReqType };
myEConnectType.RQeConnectOutType = myReqOutType;
// Serialize the eConnect document object to a memory stream
MemoryStream myMemStream = new MemoryStream();
XmlSerializer mySerializer = new XmlSerializer(myEConnectType.GetType());
mySerializer.Serialize(myMemStream, myEConnectType);
myMemStream.Position = 0;
// Load the serialized eConnect document object into an XML document object
XmlTextReader xmlreader = new XmlTextReader(myMemStream);
XmlDocument myXmlDocument = new XmlDocument();
myXmlDocument.Load(xmlreader);
string reqDoc = requester.GetEntity(GPCongfigSettings.GPConnectionString, myXmlDocument.OuterXml);
return "Correct Connection";
}
catch (eConnectException exc)
{
Console.WriteLine(exc.Message);
return "eConnect Excpetion";
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
return "Excpetion";
}
}
private void btnExit_Click(object sender, EventArgs e)
{
this.Close();
}
}

You are not handling the eConnectException. You are showing a message in the Console and then essentially rethrowing the exception by returning false.
If you do handle an exception then you should return true to avoid rethrowing it:
catch (AggregateException ae)
{
ae.Handle((x) =>
{
if (x is eConnectException) // This we know how to handle.
{
Console.WriteLine("Incorrect Database Name! -- " + x.Message);
}
return x is eConnectException; //rethrow anything that is not an eConnectException
});
}

blocking listen prevents disconnect

Overview of Problem:
I need to connect to an IRC Server. Once connected, the program will send a message to the channel, and a response will occur over multiple lines back. I need to read these lines and store in a variable for later use. A special character at the end of the message (]) will define the end of the message over multiple lines. Once we have received this character, the IRC session should disconnect and processing should continue.
Situation:
I am using the Smartirc4net library. Calling irc.Disconnect() takes about 40 seconds to disconnect the session. Once we've received the ] character, the session should be disconnected, Listen() should not be blocking, and the rest of the program should continue to run.
Research:
I have found this: smartirc4net listens forever, can't exit thread, and I think it might be the same issue, however, I am unsure of what I need to do to resolve the problem.
Code:
public class IrcCommunicator
{
public IrcClient irc = new IrcClient();
string data;
public string Data { get { return data; } }
// this method we will use to analyse queries (also known as private messages)
public void OnQueryMessage(object sender, IrcEventArgs e)
{
data += e.Data.Message;
if (e.Data.Message.Contains("]"))
{
irc.Disconnect(); //THIS TAKES 40 SECONDS!!!
}
}
public void RunCommand()
{
irc.OnQueryMessage += new IrcEventHandler(OnQueryMessage);
string[] serverlist;
serverlist = new string[] { "127.0.0.1" };
int port = 6667;
string channel = "#test";
try
{
irc.Connect(serverlist, port);
}
catch (ConnectionException e)
{
// something went wrong, the reason will be shown
System.Console.WriteLine("couldn't connect! Reason: " + e.Message);
}
try
{
// here we logon and register our nickname and so on
irc.Login("test", "test");
// join the channel
irc.RfcJoin(channel);
irc.SendMessage(SendType.Message, "test", "!query");
// here we tell the IRC API to go into a receive mode, all events
// will be triggered by _this_ thread (main thread in this case)
// Listen() blocks by default, you can also use ListenOnce() if you
// need that does one IRC operation and then returns, so you need then
// an own loop
irc.Listen();
// when Listen() returns our IRC session is over, to be sure we call
// disconnect manually
irc.Disconnect();
}
catch (Exception e)
{
// this should not happen by just in case we handle it nicely
System.Console.WriteLine("Error occurred! Message: " + e.Message);
System.Console.WriteLine("Exception: " + e.StackTrace);
}
}
}
IrcBot bot = new IrcBot();
bot.RunCommand();
ViewBag.IRC = bot.Data;
As you can see, once this
Thank you for your time to look at this code and read my problem description. If you have any thoughts, or other suggestions, please let me know.
Mike

I was able to successfully disconnect straight away by calling RfcQuit() within OnQueryMessage(), before irc.Disconnect();

NetworkStream Equivelant

I have been trying to create a metro application but there is a problem: StreamSocket doesn't really do what I want to do (I think)
Here is an excerpt my code from .Net that works:
try
{
TCP = new TcpClient(server, port);
Stream = TCP.GetStream();
Read = new StreamReader(Stream);
Write = new StreamWriter(Stream);
}
catch (Exception e)
{
Console.WriteLine("Error connecting to " + server + ": " + e);
return;
}
// Identify
Write.WriteLine("LOGIN " + Username);
Write.Flush();
while (Connected)
{
try
{
if ((line = Read.ReadLine()) != null && Connected)
I can't get StreamSocket to work... it requires you to know the length of the string that's coming in and I don't know what it will be - it varies. Is there any way to do this that will work?
This is what I have but it doesn't work:
try
{
// Connect to the server (in our case the listener we created in previous step).
await Socket.ConnectAsync(new HostName("example.com"), "1111");
}
catch (Exception exception)
{
// If this is an unknown status it means that the error is fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
}
// Create a DataWriter if we did not create one yet. Otherwise use one that is already cached.
Writer = new DataWriter(Socket.OutputStream);
Listener = new DataReader(Socket.InputStream);
Debug.WriteLine(Socket.Information.RemoteAddress.CanonicalName); //Check if IP is correct
SendRaw("LOGIN " + Nickname);
string line = "";
Connected = true;
while (Connected)
{
if (Listener.UnconsumedBufferLength != 0)
{
line = Listener.ReadString(Listener.UnconsumedBufferLength);
Debug.WriteLine(line);
}
}
}
async public void SendRaw(string str)
{
Writer.WriteString(str);
// Write the locally buffered data to the network.
try
{
await Writer.StoreAsync();
}
catch (Exception exception)
{
// If this is an unknown status it means that the error if fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
}
}
Any help would be appreciated!

First things first: your original code is a DOS attack waiting to happen. If possible, I would recommend changing the protocol to include a length prefix before every string so you can tell how big it will be before allocating memory for it.
Second things second: the DataReader class must read a number of bytes into its internal buffer before it can interpret them. You read into this buffer by calling LoadAsync.
However, if you want to read a string of arbitrary length, you'll have to read into a buffer and scan for your newline yourself, resizing the buffer (or adding new buffers) as necessary if the newline isn't found, up to some maximum size.
Update:
Set InputStreamOptions to Partial; the you can call LoadAsync with an arbitrary large buffer size (e.g. 1024). After getting data, call ReadString(UnconsumedBufferLength). Each time you do this, you may get part of a line, a line, or more than a line. So you'll have to build up a string and then Split by \n, keeping any partial line at the end for the next time through the loop.