Generated Program.cs uses special way of disposing native resource

[Guest]

Hi,

To properly clean up native resources, one should always use "using (Blah
blah = new Blah())" for types "Blah" that implement IDisposable. It seems to
me that the code generated by Visual Studio in Program.cs doesn't live by
this rule? A form is always IDisposable, so who calls the .Dispose() method
on the form?

[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MyForm());
}


And what about, if I change the code into this (below):

[STAThread]
static void Main()
{
MyForm myForm = new MyForm();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(myForm);
myForm.DoSomethingThatUsesTheFormObjectExtensivly();
}

The reason why I'm asking about this is because I'm having trouble with
system tray icons that are left after my application exits. Normally this
works fine, but when I stopped using Application.Run() things got hairy. I'm
not sure the normal Application.Run() because I'm trying to use
Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run()
instead, in order to get a clean implementation of "single instance
application".

My question is, why isn't the Form1() instance in the generated code wrapped
into some kind of "using" statement? Is there some kind of special case going
on here?


Regards,
Martin

 

[Mehdi]

[STAThread]
static void Main()
{
MyForm myForm = new MyForm();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(myForm);
myForm.DoSomethingThatUsesTheFormObjectExtensivly();
}

The reason why I'm asking about this is because I'm having trouble with
system tray icons that are left after my application exits. Normally this
works fine, but when I stopped using Application.Run() things got hairy. I'm
not sure the normal Application.Run() because I'm trying to use
Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run()
instead, in order to get a clean implementation of "single instance
application".

I'm not sure what you mean by "I stopped using Application.Run()". Anyway,
i had a similar problem a while ago with system tray icons sticking in the
system tray after the application exited and I think that i solved the
problem by disposing the tray icon object manually before the app exited.

My question is, why isn't the Form1() instance in the generated code wrapped
into some kind of "using" statement? Is there some kind of special case going
on here?

Because the documentation of Application.Run states that the form's Dispose
method will be called before Run() returns.

 

[Guest]

Thanks Mehdi.

What I meant by "not using Application.Run()" is that instead of calling
this method I call
theMicrosoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run().
However, I'm not sure whether
Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run()
will actually call Application.Run() or not.

As you say the documentation for Application.Run() says that the form will
be disposed. When the form is disposed the notify icon will also be disposed
automatically. When I switched from using Application.Run() to
Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run()
it seems like the form (and thus also the notify icon) was no longer being
disposed correctly. I find this to be quite confusing, I wish they didn't
call dispose from application.run() but instead used the "using-statement"
because having a call to dispose inside application.run() is quite subtle.

Anyway, again thanks for replying!



Regards,
Martin

[STAThread]
static void Main()
{
MyForm myForm = new MyForm();
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(myForm);
myForm.DoSomethingThatUsesTheFormObjectExtensivly();
}

The reason why I'm asking about this is because I'm having trouble with
system tray icons that are left after my application exits. Normally this
works fine, but when I stopped using Application.Run() things got hairy. I'm
not sure the normal Application.Run() because I'm trying to use
Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run()
instead, in order to get a clean implementation of "single instance
application".

I'm not sure what you mean by "I stopped using Application.Run()". Anyway,
i had a similar problem a while ago with system tray icons sticking in the
system tray after the application exited and I think that i solved the
problem by disposing the tray icon object manually before the app exited.

My question is, why isn't the Form1() instance in the generated code wrapped
into some kind of "using" statement? Is there some kind of special case going
on here?

Because the documentation of Application.Run states that the form's Dispose
method will be called before Run() returns.