How to Override Maximize Button in WPF?

Question

I want to override maximize button of window in WPF to resize width and height more than one monitor. How to do it? Thanks!

Answer 1

Check this: https://stackoverflow.com/a/52035623/9912441

You need to find total width and height of all monitor with the monitor info.

[DllImport("user32")]
internal static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);

[DllImport("User32")]
internal static extern IntPtr MonitorFromWindow(IntPtr handle, int flags);

/// </summary>
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public class MONITORINFO
{
     /// <summary>
     /// </summary>            
     public int cbSize = Marshal.SizeOf(typeof(MONITORINFO));

     /// <summary>
     /// </summary>            
     public RECT rcMonitor = new RECT();

     /// <summary>
     /// </summary>            
     public RECT rcWork = new RECT();

     /// <summary>
     /// </summary>            
     public int dwFlags = 0;
}

void Maximize(HWND hWnd, HMONITOR hMonitor)
{
    // access monitor info
    MONITORINFO monitorInfo = { sizeof(MONITORINFO) };
    GetMonitorInfo(hMonitor, &monitorInfo);

    // restore window to normal size if it is not yet
    ShowWindow(hWnd, SW_RESTORE);

    // move window to the monitor
    SetWindowPos(hWnd, nullptr, monitorInfo.rcMonitor.left, 
    monitorInfo.rcMonitor.top, 0, 0, SWP_NOZORDER | SWP_NOSIZE);

    // maximize window
    ShowWindow(hWnd, SW_MAXIMIZE);    
}