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Console and form in one and data transfer?

There is a code represents Console Application where I've done new Thread for the form and displaying a CustomForm on our new thread, I've also tried some kind of data transfer but I haven't successed.
Program.cs code ...
class Program {
public static CustomForm _customForm {
get {
return customForm;
}
set {
customForm = value;
customForm.Show();
}
}
private static CustomForm customForm;
/// <summary>
/// Static method which constains all the magic for the console!
/// </summary>
/// <param name="args"></param>
static void Main(string[] args) {
// Declaring Thread for the FormThread.
Thread formThread = new Thread(new ThreadStart(FormThread));
// Fires out the work of the thread.
formThread.Start();
Console.ReadKey();
// And console is still running?
// Thread formThread is still running too, thats the reason bruh!
}
/// <summary>
/// Static method which constains all the magic for the form!
/// </summary>
static void FormThread() {
customForm.lbl.Text = "Yolo, it wurks!";
Application.Run(new CustomForm());
}
}
CustomForm.cs code ...
public partial class CustomForm : Form {
public string lblText {
get {
return lbl.Text;
}
set {
lbl.Text = value;
}
}
/// <summary>
/// Just initializer, something what we'll never understand.
/// </summary>
public CustomForm() {
InitializeComponent();
}
/// <summary>
/// When the form is loaded.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void OnLoad(object sender, EventArgs e) {
Program._customForm = this;
}
}
The only thing I want to do is call the lbl's text property and set some value in a program.cs, not in the customform.cs
Sometimes form wont to show or the lbl in the form isn't changed.

customForm.lbl.Text = "Yolo, it wurks!"; executes before you are creating CustomForm.
Probably, you need to create your form in the main and pass it into Application.Run(CustomForm);
static void Main(string[] args) {
// Declaring Thread for the FormThread.
Thread formThread = new Thread(new ThreadStart(FormThread));
// Fires out the work of the thread.
customForm = new CustomForm();
formThread.Start();
Console.ReadKey();
// And console is still running?
// Thread formThread is still running too, thats the reason bruh!
}
Also, you can't change a control property from other threads. In order to change property from other thread use Invoke method.
public partial class CustomForm : Form {
public string lblText
{
get
{
return lbl.Text;
}
set
{
if (lbl.InvokeRequired)
lbl.Invoke((MethodInvoker) (() => lbl.Text = value));
else
lbl.Text = value;
}
}
}

Fire Event on Background Thread [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 10 years ago.
My apologies I was not accurate in my question and effort. I am developing Console application which has different components. Now I have decoupled them and want them to interact them using asynchronous Publisher/Subscriber way; similar to WPF. So in this case I will have one Master thread which will always be there and depending on request it will invoke event e.g. DataRequested which would be fired on background thread. Once Background thread completes process it will fire event again e.g. DataCompleted which should come back to the calling thread i.e. Master thread. I hope I am clear in my explanation.
So far I have coded below; where I have EventBroker.
public class EventBroker
{
public static event EventHandler SubscriptionAdded;
public static event EventHandler SubscriptionRemoved;
private static volatile EventBroker instance;
private static object syncRoot = new Object();
private static Dictionary<string, List<Delegate>> subscriptions;
/// <summary>
/// Initializes a new instance of the <see cref="T:EventBroker"/> class.
/// </summary>
private EventBroker()
{
}
/// <summary>
/// Gets the instance.
/// </summary>
/// <value>The instance.</value>
public static EventBroker Instance
{
get
{
if (instance == null)
{
lock (syncRoot)
{
if (instance == null)
{
instance = new EventBroker();
subscriptions = new Dictionary<string, List<Delegate>>();
}
}
}
return instance;
}
}
/// <summary>
/// Gets or sets the internal subscriptions dictionary.
/// </summary>
/// <value>The subscriptions.</value>
private static Dictionary<string, List<Delegate>> Subscriptions
{
get { return EventBroker.subscriptions; }
set
{
lock (syncRoot)
{
EventBroker.subscriptions = value;
}
}
}
/// <summary>
/// Raises the subscription added event.
/// </summary>
/// <param name="e">The <see cref="T:System.EventArgs"/> instance containing the event data.</param>
private static void OnSubscriptionAdded(EventArgs e)
{
if (SubscriptionAdded != null)
SubscriptionAdded(instance, e);
}
/// <summary>
/// Raises the subscription removed event.
/// </summary>
/// <param name="e">The <see cref="T:System.EventArgs"/> instance containing the event data.</param>
private static void OnSubscriptionRemoved(EventArgs e)
{
if (SubscriptionRemoved != null)
SubscriptionRemoved(instance, e);
}
/// <summary>
/// Subscribe method to the specified event.
/// </summary>
/// <param name="id">The id.</param>
/// <param name="method">The method Delegate to be invoked when Event fires.</param>
public static void Subscribe(string id, Delegate method)
{
//Check if there is a existing event
List<Delegate> delegates = null;
if (Subscriptions == null)
Subscriptions = new Dictionary<string, List<Delegate>>();
if (Subscriptions.ContainsKey(id))
{
delegates = subscriptions[id];
}
else
{
delegates = new List<Delegate>();
Subscriptions.Add(id, delegates);
}
delegates.Add(method);
OnSubscriptionAdded(new EventArgs());
}
/// <summary>
/// Unsubscribe method from event notifications
/// </summary>
/// <param name="id">The id.</param>
/// <param name="method">The method.</param>
public static void Unsubscribe(string id, Delegate method)
{
if (Subscriptions.ContainsKey(id))
{
if (Subscriptions[id].Contains(method))
{
Subscriptions[id].Remove(method);
OnSubscriptionRemoved(new EventArgs());
}
if (Subscriptions[id].Count == 0)
Subscriptions.Remove(id);
}
}
/// <summary>
/// Fire the specified event by and pass parameters.
/// </summary>
/// <param name="id">The id.</param>
/// <param name="args">The args.</param>
public static void Execute(string id, object sender, EventArgs e)
{
if (Subscriptions.ContainsKey(id))
{
for (int i = 0; i < Subscriptions[id].Count; i++)
{
Delegate x = Subscriptions[id][i];
DynamicInvoke(id, x, sender, e);
if (!Subscriptions.ContainsKey(id))
break;
}
}
}
/// <summary>
/// Checks to see if target of invocation is still a valid
/// (non-disposed objects). Then it dinamicly invokes Delegate.
/// </summary>
/// <param name="id">Event ID</param>
/// <param name="x">Delegate to invoke</param>
/// <param name="args">Object array of arguments</param>
private static void DynamicInvoke(string id, Delegate x, object sender, EventArgs e)
{
if (x.Method != null)
{
if (x.Target is Control)
{
Control ctl = (Control)x.Target;
if (ctl.IsDisposed)
{
Unsubscribe(id, x);
return;
}
}
if (x.Target == null)
{
Unsubscribe(id, x);
return;
}
x.DynamicInvoke(sender, e); ***//this becomes blocking call untill EventHandle is completed and hangs Master Thread***
}
}
}
I use this EventBroker to keep track of my Subscribers and once Publisher comes I invoke certain delegate. But it gets invoked only on Master thread and it gets hanged. I want to invoke EventHandler on separate thread.
public class MasterClass
{
public MasterClass()
{
EventBroker.Subscribe("Topic2", new EventHandler<EventArgs<string>>(CallBackfromWorker));
}
public void InvokeTest()
{
EventArgs<string> EventArgs = new EventArgs<string>("Test");
EventBroker.Execute("Topic1", null, EventArgs); //I want both of this to be asynchronous.
}
public void CallBackfromWorker(object sender, EventArgs<string> e)
{
Debug.Pring("Get Called Asynchronously from Worker thread through Event");
}
}
**//Worker Class**
public class WorkerClass
{
public WorkerClass()
{
EventBroker.Subscribe("Topic1", new EventHandler<EventArgs<string>>(HandleRapRequest1));
}
public void HandleRapRequest1(string RAPRequest)
//public void HandleRapRequest1(object sender, EventArgs<string> e)
{
Logger.LogToDisplay("WorkerClass Request" + RAPRequest);
Logger.LogToDisplay("AsyncClient : " + System.Threading.Thread.CurrentThread.IsBackground);
Logger.LogToDisplay("AsyncClient : " + System.Threading.Thread.CurrentThread.ManagedThreadId);
Logger.LogToDisplay("Going to Sleep");
System.Threading.Thread.Sleep(10000); ***//Hangs my Master Thread***
EventBroker.Execute("Topic2", null, EventArgs); //I want both of this to be asynchronous.
}
}
So bottom line is I am looking for Asynchronous Eventbased Publisher/Subscriber in Console application...similar to CAB event sin SCSF and in WPF...
Thanks

This is simple enough to do:
public class Foo
{
public event Action MyEvent;
public void FireEvent()
{
Action myevent = MyEvent;
if (myevent != null)
{
Task.Factory.StartNew(() => myevent())
.ContinueWith(t =>
{
//TODO code to run in UI thread after event runs goes here
}, CancellationToken.None
, TaskContinuationOptions.None
, TaskScheduler.FromCurrentSynchronizationContext());
}
}
}
If you're using C# 5.0 you can use await which simplifies this code:
public class Foo
{
public event Action MyEvent;
public async Task FireEvent()
{
Action myevent = MyEvent;
if (MyEvent != null)
{
await Task.Run(() => myevent());
//TODO code to run in UI thread after event runs goes here
}
}
}
If you don't need the code running in the UI thread to start after the event handlers are all completed, and it can instead keep going on the UI thread at the same time, you can also simplify the code to just:
public class Foo
{
public event Action MyEvent;
public void FireEvent()
{
Action myevent = MyEvent;
if (MyEvent != null)
{
Task.Factory.StartNew(() => myevent());
//TODO code to run in UI thread while event handlers run goes here
}
}
}

Ensuring execution order between multiple threads

I am having a kinda annoying problem mostly due to my low skill level/experience in C# multithreading.
Here is the background. In my framework, I have a static class named WaitFormHelper, which has two static methods (well... actually more but we don't care here), Start() and Close()
The Start() method initializes and starts a thread which will acquire a lock on the locker object and create a WaitForm (which is a small loading control with a custom message and a progress bar)
In my current project, I have a method which starts a WaitForm, performs calculations, then closes the WaitForm. Nothing fancy at all.
The method looks like the following, I simplified it as much as possible:
public void PerformCalculations()
{
try
{
WaitFormHelper.Start("Title", "message", false);
if (this.CalculationsParameters.IsInvalid)
{
return;
}
// Perform all those lengthy calculations here
}
// catch whatever exception I may have to catch, we don't care here
finally
{
WaitFormHelper.Close();
}
}
Here are the Start() and Close() methods with related methods & attributes, simplified as well:
private static Thread instanceCaller;
private static WaitForm instance;
private static AutoResetEvent waitFormStarted = new AutoResetEvent(false);
private static object locker = new object();
/// <summary>
/// Initializes WaitForm to start a single task
/// </summary>
/// <param name="header">WaitForm header</param>
/// <param name="message">Message displayed</param>
/// <param name="showProgressBar">True if we want a progress bar, else false</param>
public static void Start(string header, string message, bool showProgressBar)
{
InitializeCallerThread(showProgressBar, header, message);
instanceCaller.Start();
}
/// <summary>
/// Initializes caller thread for executing a single command
/// </summary>
/// <param name="showProgressBar"></param>
/// <param name="header"></param>
/// <param name="message"></param>
private static void InitializeCallerThread(bool showProgressBar, string header, string message)
{
waitFormStarted.Reset();
instanceCaller = new Thread(() =>
{
lock (locker)
{
instance = new WaitForm()
{
Header = header,
Message = message,
IsProgressBarVisible = showProgressBar
};
waitFormStarted.Set();
}
instance.ShowDialog();
});
instanceCaller.Name = "WaitForm thread";
instanceCaller.SetApartmentState(ApartmentState.STA);
instanceCaller.IsBackground = true;
}
/// <summary>
/// Closes current form
/// </summary>
public static void Close()
{
lock (locker)
{
if (instance != null && !instance.IsClosed)
{
waitFormStarted.WaitOne();
instance.FinalizeWork();
instance.Dispatcher.Invoke(
new Action(() =>
{
instance.Close();
}));
}
}
}
Now let's get to the problem
This usually works fine, except in this case:
If this.CalculationsParameters.IsInvalid is true (ie. as you probably already understood, I can't perform calculations for some reason, such as "user entering crap in my forms"), the execution directly closes my WaitForm.
However in this case, the main thread will reach the Close method and acquire a lock on the locker object before the thread fired by the Start() method.
What happens is that: Close acquires lock, tries to close the form but instance is still null because the Thread created in InitializeCallerThread is still waiting for the lock to actually create it. Close releases lock, InitializeCallerThread acquires it and... shows a WaitForm which will not close.
Now I know that I can simply fix this problem by testing if the calculation parameters are invalid before actually starting the WaitForm, but well, problem is this WaitForm is supposed to be used by all applications of our framework (which includes 40+ different apps used and maintained in 4 countries), so ideally I'd rather prefer seeing my WaitForm working at all cases.
Do you have any idea on how could I synchronize this to make sure the starter thread is definitely called and executed first?
As you can see I already use an AutoResetEvent for this matter, but if I listen to it before the test if (instance != null) I will end up stuck in my case.
Hope this is clear enough! Thank you!

You need some mechanism to make a "queue control", coordinating steps according to the order you want them occurring.
Recently I have needed to implement something like this to force a specific order in the execution of several threads in a unit test.
Here is my suggestion:
QueueSynchronizer:
/// <summary>
/// Synchronizes steps between threads.
/// </summary>
public class QueueSynchronizer
{
/// <summary>
/// Constructor.
/// </summary>
/// <param name="minWait">Minimum waiting time until the next try.</param>
/// <param name="maxWait">Maximum waiting time until the next try.</param>
public QueueSynchronizer(Int32 minWait, Int32 maxWait)
{
}
private Mutex mx = new Mutex();
/// <summary>
/// Minimum waiting time until the next try.
/// </summary>
private Int32 minWait = 5;
/// <summary>
/// Maximum waiting time until the next try.
/// </summary>
private Int32 maxWait = 500;
int currentStep = 1;
/// <summary>
/// Key: order in the queue; Value: Time to wait.
/// </summary>
private Dictionary<int, int> waitingTimeForNextMap = new Dictionary<int, int>();
/// <summary>
/// Synchronizes by the order in the queue. It starts from 1. If is not
/// its turn, the thread waits for a moment, after that, it tries again,
/// and so on until its turn.
/// </summary>
/// <param name="orderInTheQueue">Order in the queue. It starts from 1.</param>
/// <returns>The <see cref="Mutex"/>The mutex that must be released at the end of turn.
/// </returns>
public Mutex Sincronize(int orderInTheQueue)
{
do
{
//while it is not the turn, the thread will stay in this loop and sleeping for 100, 200, ... 1000 ms
if (orderInTheQueue != this.currentStep)
{
//The next in queue will be waiting here (other threads).
mx.WaitOne();
mx.ReleaseMutex();
//Prevents 100% processing while the current step does not happen
if (!waitingTimeForNextMap.ContainsKey(orderInTheQueue))
{
waitingTimeForNextMap[orderInTheQueue] = this.minWait;
}
Thread.Sleep(waitingTimeForNextMap[orderInTheQueue]);
waitingTimeForNextMap[orderInTheQueue] = Math.Min(waitingTimeForNextMap[orderInTheQueue] * 2, this.maxWait);
}
} while (orderInTheQueue != this.currentStep);
mx.WaitOne();
currentStep++;
return mx;
}
}
Start() and Close() with QueueSynchronizer:
//synchronizer
private static QueueSynchronizer queueSynchronizer;
private static Thread instanceCaller;
private static WaitForm instance;
private static AutoResetEvent waitFormStarted = new AutoResetEvent(false);
private static object locker = new object();
/// <summary>
/// Initializes WaitForm to start a single task
/// </summary>
/// <param name="header">WaitForm header</param>
/// <param name="message">Message displayed</param>
/// <param name="showProgressBar">True if we want a progress bar, else false</param>
public static void Start(string header, string message, bool showProgressBar)
{
queueSynchronizer = new QueueSynchronizer();
InitializeCallerThread(showProgressBar, header, message);
instanceCaller.Start();
}
/// <summary>
/// Initializes caller thread for executing a single command
/// </summary>
/// <param name="showProgressBar"></param>
/// <param name="header"></param>
/// <param name="message"></param>
private static void InitializeCallerThread(bool showProgressBar, string header, string message)
{
waitFormStarted.Reset();
instanceCaller = new Thread(() =>
{
lock (locker)
{
//Queuing to run on first.
Mutex mx = queueSynchronizer.Sincronize(1);
try
{
instance = new WaitForm()
{
Header = header,
Message = message,
IsProgressBarVisible = showProgressBar
};
}
finally
{
//I think is here that ends the first step!?
mx.ReleaseMutex();
}
waitFormStarted.Set();
}
instance.ShowDialog();
});
instanceCaller.Name = "WaitForm thread";
instanceCaller.SetApartmentState(ApartmentState.STA);
instanceCaller.IsBackground = true;
}
/// <summary>
/// Closes current form
/// </summary>
public static void Close()
{
//Queuing to run on second.
Mutex mx = queueSynchronizer.Sincronize(2);
try
{
lock (locker)
{
if (instance != null && !instance.IsClosed)
{
waitFormStarted.WaitOne();
instance.FinalizeWork();
instance.Dispatcher.Invoke(
new Action(() =>
{
instance.Close();
}));
}
}
}
finally
{
mx.ReleaseMutex();
}
}

You need to Join on the thread that you created. By joining on a thread you'll block at that point until the thread has finished executing.
public static void Close()
{
lock (locker)
{
instanceCaller.Join();
if (instance != null && !instance.IsClosed)
{
waitFormStarted.WaitOne();
instance.FinalizeWork();
instance.Dispatcher.Invoke(
new Action(() =>
{
instance.Close();
}));
}
}
}

C# While Loop in Worker Thread for listening command and response

Overview of the problem:
I try to use a thread (while..loop) to listen a command from user. If user send a command, it will assign new value in the global variable which is in the class (LoopingWorkerThread).
I don't understand if I don't put the thread sleep value lower than 10 milliseconds, and I wouldn't get any response (it is in the ListenCommand method) . Look like the global parameter is being overwritten "_CommandReceived" in the method, probably the processor run to fast and ignore the value of the parameter had changed ("_CommandReceived").
Kindly comment if there is any better mechanism. I had lock it in the ListenCommand while loop.
The following are the codes:
public class LoopingWorkerThread
{
/// <summary>
/// Local main thread for LoopingWorkerThread
/// </summary>
private Thread t;
/// <summary>
/// Local parameter to identify the LoopingWorkerThread Is On
/// </summary>
private bool _IsOn;
/// <summary>
/// Local parameter to store command received from user
/// </summary>
private int _CommandReceived;
/// <summary>
/// Local object to use for locking the LoopingWorker Thread
/// </summary>
private object _LockListenCommand = new object();
/// <summary>
/// Properties of LoopingWorker Thread Is On
/// </summary>
public bool IsOn
{
get { return _IsOn; }
set { _IsOn = value; }
}
/// <summary>
/// Property of storing the command received from user
/// </summary>
public int CommandReceived
{
get { return _CommandReceived; }
set { _CommandReceived = value; }
}
/// <summary>
/// Delegate for OnResponse Event Handler
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public delegate void OnResponseHandler(object sender, ResponseArg e);
/// <summary>
/// Event of OnResponse
/// </summary>
public event OnResponseHandler OnResponse;
/// <summary>
/// Constructor of LoopingWorkerThread Class
/// </summary>
public LoopingWorkerThread()
{
_IsOn = false;
}
/// <summary>
/// Method of LoopingWorkerThread Function
/// </summary>
private void ListenCommand()
{
lock (_LockListenCommand)
while (_IsOn)
{
switch (_CommandReceived)
{
case 0:
// Ignore default command
break;
case 1:
FireOnResponse("Received cmd 1, response [Hello One]");
break;
case 2:
FireOnResponse("Received cmd 2, response [Hello Two]");
break;
default:
FireOnResponse("Error. Received unidentified command - " + _CommandReceived.ToString());
break;
}
//Console.WriteLine("ThreadProc: Cmd:[{0}] - Response:{1}", _CommandReceived.ToString(), ReaderResponse);
// Reset or Clear the Command Received
_CommandReceived = 0;
// If the sleep less than 10 millisecond, it always don't catch the
// command received which assigned to 1 or 2. Don't understand, or is there
// any better method.
**Thread.Sleep(10);**
}
}
/// <summary>
/// Function of firing response event back to user
/// </summary>
/// <param name="message"></param>
private void FireOnResponse(string message)
{
ResponseArg myarg = new ResponseArg(message);
if (OnResponse != null)
OnResponse(this, myarg);
}
/// <summary>
/// Method of starting the LoopingWorkerThread
/// </summary>
public void Start()
{
_IsOn = true;
FireOnResponse("Main thread: Started.");
// The constructor for the Thread class requires a ThreadStart
// delegate that represents the method to be executed on the
// thread. C# simplifies the creation of this delegate.
t = new Thread(new ThreadStart(ListenCommand));
// Start ThreadProc. Note that on a uniprocessor, the new
// thread does not get any processor time until the main thread
// is preempted or yields. Uncomment the Thread.Sleep that
// follows t.Start() to see the difference.
t.Start();
//Thread.Sleep(0);
FireOnResponse("Main thread: Call Start().");
}
/// <summary>
/// Method of stopping the LoopingWorkerThread
/// </summary>
public void Stop()
{
_IsOn = false;
t.Join();
//t.Abort();
FireOnResponse("LoopingWorker Thread is stopped.");
}
/// <summary>
/// Method of sending command to the LoopingWorkerThread
/// </summary>
/// <param name="readercmd"></param>
public void SendCommand(int readercmd)
{
_CommandReceived = readercmd;
}
}

Your code works because Thread.Sleep produces the necessary memory barrier required to read _commandReceived correctly. If you remove the Thread.Sleep call then you also remove the implicit memory barrier. Obviously, this is not a good mechanism to rely on though.
More importantly you are going about this the wrong way. What you should be using is the producer-consumer pattern. This is pretty easy with the BlockingCollection class since it blocks the consumer on Take while the queue is empty.
public class Example
{
private BlockingCollection<int> commands = new BlockingCollection<int>();
public Example()
{
var thread = new Thread(Run);
thread.IsBackground = true;
thread.Start();
}
public void SendCommmand(int command)
{
commands.Add(command);
}
private void Run()
{
while (true)
{
int command = commands.Take();
ProcessCommand(command);
}
}
private void ProcessCommand(int command)
{
// Process the command here.
}
}
BlockingCollection is available for 3.5 as part of the Reactive Extensions download.

Try declaring the variable volatile. More about this on http://msdn.microsoft.com/en-us/library/x13ttww7.aspx

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);
}