control.BeginInvoke() 调用委托失败

Question

I noticed that control.BeginInvoke(delegate) some times fail to call the delegate. I understand that BeginInvoke just creates a PostMessage and that message is handled by the application later (post message limit by default is 10,000). Given that our application is not very complex, Is there any other reason why it can fail to execute the delegate? My code is something like below.

class MyClass : Form{

    private bool executing = false;
    private delegate void DelegateBar(string info, int total, bool status, object obj);
    private void Bar(string info, int total, bool status, object obj){
        log("Enterning Bar");
        // Update something on UI
        executing = false;
        log("Exiting Bar");
    }
    public void foo(){
        log("Entering Foo");
        executing = true;
            try{
            // do something over the network
            }catch(Exception e){
                // probably network down. Lets not worry about it
            }
        DelegateBar barPtr = new DelegateBar(Bar);
        // Update UI .. call on form : form is a control
        this.BeginInvoke(barPtr, new object[] {"someInfo", 3, false, null});
        log("Exiting Fool");
    }

    public void callMeEveryFiveSeconds(){
        if(!executing) foo();
    }

    private delegate void DelegateCallMe();

    // execute every 5 seconds.
    private void timer1_Tick(object sender, EventArgs e)
    {
        Delegate del = new DelegateCallMe(callMeEveryFiveSeconds);
        // appoligies if syntax is not right, it to convey the idea that callMeEveryFiveSeconds is called on the main thread (asynchronously)
        this.beginInvoke(del, new object[]{});
    }
}

Answer 1

The code looks fine to me as posted. If this does not match your code in use then I would suggest looking for one of the following:

1) If your consuming task takes longer then the FiveSeconds method to give the appearance of not being called every time

2) If the combination of the consuming task and Updating the UI results in the appearance of the method not being called every time

3) If any of the code not shown in the consuming task could alter the value of executing (or exit the method because it can be set to false)