EnumChildWindows (Win32 error 127) (c#)

[Ryan Ross]

Hello,

I am having the oddest error with the EnumChildWindows function. Below are
the imports, and the methods.

[DllImport("user32.dll", SetLastError=true)]

public static extern int EnumChildWindows(IntPtr hWndParent, EnumChildProc
callback, int lParam);

public delegate int EnumChildProc(IntPtr hwnd, long lParam);

public void M_initChildWindows()

{

if(WindowObject_Basic_GDI_Handle != IntPtr.Zero)

{

try

{

User32.EnumChildWindows(WindowObject_Basic_GDI_Han dle, new
User32.EnumChildProc(M_addChildWindows), 0);

}

catch(Exception e)

{

System.Diagnostics.Debug.WriteLine("Child Window failure: " +
e.Message);

}

}
}

private int M_addChildWindows(IntPtr Window, long Data)

{
if(Window != IntPtr.Zero)

{

ChildWindowObject_Basic c_WindowObject_Basic = new
ChildWindowObject_Basic(Window);

c_WindowObject_Basic_Array.Add(c_WindowObject_Basi c);

}


return 1;

}

I keep getting a 127 error, even though it appears to enumerate the windows.
I placed it within a try statement to continue working other things, but
it's coming back to bite me in the ass.

Anyone have any ideas?

Thanks,

Ryan

[Nicholas Paldino [.NET/C# MVP]]

Ryan,

Your declaration of the callback delegate and function is incorrect. It
should be:

[DllImport("user32.dll", SetLastError=true)]
public static extern int EnumChildWindows(IntPtr hWndParent, EnumChildProc
callback, IntPtr lParam);

public delegate int EnumChildProc(IntPtr hwnd, IntPtr lParam);

LPARAM translates to an IntPtr.

Also, as an aside, you might want to check your publicly exposed method
names. They violate the public naming convention (M_initChildWindows, for
example).

Hope this helps.

--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Ryan Ross" <ry***@nni.com> wrote in message
news:5O********************@nni.com...

Hello,

I am having the oddest error with the EnumChildWindows function. Below are
the imports, and the methods.

[DllImport("user32.dll", SetLastError=true)]

public static extern int EnumChildWindows(IntPtr hWndParent, EnumChildProc
callback, int lParam);

public delegate int EnumChildProc(IntPtr hwnd, long lParam);

public void M_initChildWindows()

{

if(WindowObject_Basic_GDI_Handle != IntPtr.Zero)

{

try

{

User32.EnumChildWindows(WindowObject_Basic_GDI_Han dle, new
User32.EnumChildProc(M_addChildWindows), 0);

}

catch(Exception e)

{

System.Diagnostics.Debug.WriteLine("Child Window failure: " +
e.Message);

}

}
}

private int M_addChildWindows(IntPtr Window, long Data)

{
if(Window != IntPtr.Zero)

{

ChildWindowObject_Basic c_WindowObject_Basic = new
ChildWindowObject_Basic(Window);

c_WindowObject_Basic_Array.Add(c_WindowObject_Basi c);

}


return 1;

}

I keep getting a 127 error, even though it appears to enumerate the
windows. I placed it within a try statement to continue working other
things, but it's coming back to bite me in the ass.

Anyone have any ideas?

Thanks,

Ryan