Can anyone tell me why this code behaves the way it does? See comments embedded in the code... Am I missing something really obvious here? using System; namespace ConsoleApplication3 { public class Program { static void Main(string[] args) { var c = new MyChild(); c.X(); Conso...
Just wondering what the difference between BeginInvoke() and Invoke() are? Mainly what each one would be used for. EDIT: What is the difference between creating a threading object and calling invoke on that and just calling BeginInvoke() on a delegate? or are they the same thing? Thanks ...
Does a System.Windows.Threading.Dispatcher work on the UI-thread of a WinForms application? If yes, why? It is coming from WindowsBase.dll which seems to be a WPF component. If not, how can I invoke work units back onto the UI-thread? I've found Control.BeginInvoke(), but it seems clumsy to create a control only to reference the origin...
On a web page, I am calling a third party who does not allow me to set timeout programatically. I call BeginInvoke and use the AsyncWaitHandle.WaitOne to wait a specified amount of time. If the call times out, I move on and forget about the thread call I began. My question is, do I still have to call EndInvoke somehow in a timeout sit...
I can't seem to figure out why I am getting an InvalidCastException running the following code: var item = new KeyValuePair<string, string>("key", "value"); Action<KeyValuePair<string, string>> kvrAction = kvr =>Console.WriteLine(kvr.Value); var result = kvrAction.BeginInvoke(item, null, null); kvrAction.EndInvoke(result); Exce...
Hi all, Here's my old code from WinForms: private void ValueChanged(double inValue1, double inValue2) { //only manual mode for this driver, so that's easy. if (ValueLabel.InvokeRequired) { ValueLabel.Invoke(new MethodInvoker(delegate { ValueLabel.Text = (inValue1* inValue2/ 1000).ToString...
Hi i've made a C# winforms application. Now i have a form which has lots of buttons, which call huge number crunching functions whose output i update in a textbox. I call the textbox.begininvoke() method to which i pass a delegate to the function which updates the text in the textbox, however when the text is huge, the form is non respon...
Why can't you pass an anonymous method as a parameter to the BeginInvoke method ? I have the following code: private delegate void CfgMnMnuDlg(DIServer svr); private void ConfigureMainMenu(DIServer server,) { MenuStrip mnMnu = PresenterView.MainMenu; if (mnMnu.InvokeRequired) { mnMnu.Begin...
Hello all, I am doing some refactoring on a piece of code to transform all blocking operations to their async counterparts. My code is in C# and is doing an UPnP query followed by an HTTP query. For this, I use the APM methods of UdpClient and WebClient (BeginReceive, and so on). My single method is now a succession of Call_1 -> Callba...
We have some code running in a background thread which needs to pop a dialog or some other user interaction, so we do the usual Invoke call on to the UI thread: Control.Invoke(SomeFunction); void SomeFunction() { ... } But, we came across a bug, our UI thread is sometimes not immediately responding to the Invoke call - we tracked i...
This page in the MS documentation, covering asynchrony in Windows Forms applications, states: You can call EndInvoke to retrieve the return value from the delegate, if neccesary, but this is not required. (emphasis added) This page covering the general case of asynchronous delegates, states something different: No matter whic...
I am trying to get my head around the use of the Action delegate type for use in forcing a timeout when methods called in a 3rd party COM dll hang up. After much searching I find that I can use Action<> or Func<> and pass up to 4 generic parameters depending on whether the method called returns a parameter or not. For this instance I wi...
I have the following: ThreadStart startThread = delegate { mySocket.StartListen(); }; mySocket is now looping on a Listen() when I: new Thread(startThread).Start(); Here is StartListen: public void StartListen() { Object locker = new Object(); // Lock resources lock (locker) { S = new System.N...
Is it possible to use Control.BeginInvoke in anything other than a "fire & forget" manner? I want to change the following request to delegate a callback method so that i can do something when each of my asynchronous calls complete. this.BeginInvoke(new RefreshRulesDelegate(RefreshRules), new object[] { ctrl, ctrl.DsRules, ctrl.CptyId })...
I need to know whether Control.BeginInvoke and Control.Invoke calls will execute in the order they are called. I have the following scenario: UI thread is blocked WCF thread calls Control.BeginInvoke WCF thread calls Control.Invoke (or possibly BeginInvoke again) UI thread is unblocked ?? The execution order of step 1-4 is guarantee...
Greetings, I am developing some application in C#. At the moment I'm dealing with threading and I have a question that I have in my mind. What is the difference between Invoke and BeginInvoke? I read some thread and I found some useful information here: here However what is the difference between Invoke and BeginInvoke in the following...
I want to display a progress bar while doing some work, but that would hang the UI and the progress bar won't update. I have a WinForm ProgressForm with a ProgressBar that will continue indefinitely in a marquee fashion. using(ProgressForm p = new ProgressForm(this)) { //Do Some Work } Now there are many ways to solve the issue, like...
Hello everyone I have got a C# user control, which has got it's own background worker thread. This worker thread is started in the constructor of the control and stopped when the control is disposed. The thread periodically calls the BeginInvoke-Method with a delegate, but sometimes the exception "Invoke or BeginInvoke cannot be called...
I have the following code to send a query to youtube and send the total result to a textbox. If I just alert the result, it's OK but I can't assign the result to a textbox. Please explain to me why? private void SearchVideo(string keyword) { string orderBy = ""; switch (cboSortBy.SelectedIndex) { case 1: orderBy = "p...
Hello everybody, hope you're well. I'm facing a curious problem with BeginInvoke and I really really need your help ! I have a class Reporting which contains multiple instances of type Report Class Reporting : UserControl { //Reports are inherited from UserControl Report _report1; Report _report2; Report _report3; //Instanc...