Question

See the following code.

The MyEnumProc runs only one time with the following code. But if I commented out the IsWindowVisible(wnd);, it runs many times.

Why IsWindowVisible make this happened(run only one time)? I thought IsWindowVisible just a function to check the wnd’s attributes?

codes of test.c:

#include <windows.h>
#include <stdio.h>
BOOL CALLBACK MyEnumProc( HWND wnd, LPARAM lParam )
{
    printf("run\n");
    IsWindowVisible(wnd);
}

int main( void )
{
    EnumDesktopWindows( NULL, MyEnumProc, 0 );
    printf("end\n");
    return 0;
}

My environment is:

Windows XP SP3.

gcc 3.4.6(mingw)

compiled option is: gcc -o test.exe test.c

I did the compile and run the test.exe in the cmd.exe.

Answer 1

EnumDesktopWindows expects you to return a value from your MyEnumProc:

return TRUE;

Read the documentation for more information.