GetWindowLong(int hWnd, GWL_STYLE) return weird numbers in c#

Question

I used GetWindowLong window api to get current window state of a window in c#.

    [DllImport("user32.dll")]
    static extern int GetWindowLong(IntPtr hWnd, int nIndex);


    Process[] processList = Process.GetProcesses();
    foreach (Process theprocess in processList)
    {

        long windowState = GetWindowLong(theprocess.MainWindowHandle, GWL_STYLE);

        MessageBox.Show(windowState.ToString());

    }

I expected to get numbers on http://www.autohotkey.com/docs/misc/Styles.htm, but I get numbers like -482344960, -1803550644, and 382554704.

Do I need to convert windowState variable?? if so, to what?

Answer 1

What is weird about those values? For example, 482344960 is equivalent to 0x1CC00000 which looks like something you might expect to see as a window style. Looking at the styles reference you linked to, that is WS_VISIBLE | WS_CAPTION | 0xC000000.

If you wanted to test for WS_VISIBLE, for example, you would do something like:

int result = GetWindowLong(theprocess.MainWindowHandle, GWL_STYLE);
bool isVisible = ((result & WS_VISIBLE) != 0);