unexpected code execution

Sanju Singh

11y1.4k

hello, in the following code

private void Window_Loaded(object sender, RoutedEventArgs e)

{

// check if any kinect is available

if (Sensors.Count == 0)

{

MessageBox.Show("no sensor is available for listening !!");

Application.Current.Shutdown();

}

///

PromptBuilder pb1 = new PromptBuilder();

pb1.AppendText("HELLO", System.Speech.Synthesis.PromptVolume.Loud);

this.speaker(pb1);

}

the last three lines are executed even though the ' if ' condition is satisfied! can anyone explain me why ? i think the application should shutdown .

13 Replies

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Vulpes11y ago
Accepted answer
You can also use the 'return' statement to prevent the code following the 'if' block from executing:

private void Window_Loaded(object sender, RoutedEventArgs e)
{
// check if any kinect is available
if (Sensors.Count == 0)
{
MessageBox.Show("no sensor is available for listening !!");
Application.Current.Shutdown();
return;
}
///
///

PromptBuilder pb1 = new PromptBuilder();
pb1.AppendText("HELLO", System.Speech.Synthesis.PromptVolume.Loud);
this.speaker(pb1);

}

I tend to prefer this to using 'else' if there would be a lot of code to indent as I like to keep indentation to a minimum. However, with just 3 lines it's a matter of taste which you use.
Sanju Singh11y ago
vulpes return statement is working fine now.
Sanju Singh11y ago
vulpes, thanks for that valuable reply. I am not saying that Application.Current.ShowDown() is not working.The application do get shut down if code outside the if condition block is executed without any error. If you get some hint on this then please share.For now i am using if-else block to avoid this. thank you
Vulpes11y ago
In theory, calling Application.Current.Shutdown() should close the application as long as:

1. It is called from the main UI thread; and

2. There are no other foreground threads running.

I thought at first that, for some unknown reason, it was allowing the current method to complete execution before shutting down.

However, I'm totally mystified as to why 'return' is not working if both Sensors.Count is zero and the MessageBox is showing :-/

You can always rely on Environment.Exit(1) and the equally brutal Environment.Failfast(message) to stop an application as it kills the process and all running threads in it (foreground or not) stone dead.

In contrast, Application.Current.ShowDown() stops the application in an orderly fashion and raises the Application.Exit event which you can handle to perform any clean-up needed.

Personally, I'm never too happy about having to resort to Environment.Exit to kill a WF or WPF application as there's always the worry that whatever is preventing normal shutdown will come back to bite you in a different way.

If I were you, I'd try to debug why Application.Current.Shutdown is not working, particularly as the whole Window_Loaded handler seems to be working in a very strange way.
Manish Kumar Choudhary11y ago
No id don't think so. just dispose the thread properly.
Sanju Singh11y ago
Environment.Exit(1) works.thanks Manish. Are there any disadvantages of using this statement?
Manish Kumar Choudhary11y ago
To stop the application running, first try:

Application.Exit();

and, if that doesn't work:

Environment.Exit(1);

Before calling either of these close all connections manually and releasing unmanaged resources by calling Dispose() on any object still in scope which implements IDisposable.
Sanju Singh11y ago
hi vulpes. return is not working. It still executes the remaining lines. well, application.current.shutdown() ; does it not terminate the execution?
Sanju Singh11y ago
break doesn't work. says there is no enclosing loop out of which to break or continue.
Manish Kumar Choudhary11y ago
use break;
private void Window_Loaded(object sender, RoutedEventArgs e)
{
// check if any kinect is available
if (Sensors.Count == 0)
{
   MessageBox.Show("no sensor is available for listening !!");
   Application.Current.Shutdown();
        break;
}
///
///

PromptBuilder pb1 = new PromptBuilder();
pb1.AppendText("HELLO", System.Speech.Synthesis.PromptVolume.Loud);
this.speaker(pb1);

}
Sanju Singh11y ago
is there something i am missing ?
Sanju Singh11y ago
well this is what i would have done in the c and c++ or java(i am new to c#).but here inside if block i am shutting down the application itself.i expect the execution to stop there itself.
Manish Kumar Choudhary11y ago
Hi sanju singh,
private void Window_Loaded(object sender, RoutedEventArgs e)

{

// check if any kinect is available

if (Sensors.Count == 0)

{

   MessageBox.Show("no sensor is available for listening !!");

   Application.Current.Shutdown();

}

///

///

else{

PromptBuilder pb1 = new PromptBuilder();

pb1.AppendText("HELLO", System.Speech.Synthesis.PromptVolume.Loud);

this.speaker(pb1);
}

}

Now it will not execute actually you did not put those condition inside else block so whenever if condition over after that last three lines will execute. The execution process is top to Bottom so after finishing the if block execution those three line will execute