I am pretty late to the club, but I believe someone coming after me may benefit out of it.
I tried several solutions but most of them failed to work in multiple displays. So, I am sharing a solution that worked perfectly for me in a commercial application.
I registered SourceInitialized event. And in the callback for the event, I added the following code,
private void Window_SourceInitialized (object sender, EventArgs e)
{
WindowSizing.WindowInitialized(this);
}
While following is the code for WindowSizing class,
public static class WindowSizing
{
const int MONITOR_DEFAULTTONEAREST = 0x00000002;
#region DLLImports
[DllImport("shell32", CallingConvention = CallingConvention.StdCall)]
public static extern int SHAppBarMessage (int dwMessage, ref APPBARDATA pData);
[DllImport("user32", SetLastError = true)]
static extern IntPtr FindWindow (string lpClassName, string lpWindowName);
[DllImport("user32")]
internal static extern bool GetMonitorInfo (IntPtr hMonitor, MONITORINFO lpmi);
[DllImport("user32")]
internal static extern IntPtr MonitorFromWindow (IntPtr handle, int flags);
#endregion
private static MINMAXINFO AdjustWorkingAreaForAutoHide (IntPtr monitorContainingApplication, MINMAXINFO mmi)
{
IntPtr hwnd = FindWindow("Shell_TrayWnd", null);
if ( hwnd == null )
return mmi;
IntPtr monitorWithTaskbarOnIt = MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
if ( !monitorContainingApplication.Equals(monitorWithTaskbarOnIt) )
return mmi;
APPBARDATA abd = new APPBARDATA();
abd.cbSize = Marshal.SizeOf(abd);
abd.hWnd = hwnd;
SHAppBarMessage((int) ABMsg.ABM_GETTASKBARPOS, ref abd);
int uEdge = GetEdge(abd.rc);
bool autoHide = System.Convert.ToBoolean(SHAppBarMessage((int) ABMsg.ABM_GETSTATE, ref abd));
if ( !autoHide )
return mmi;
switch ( uEdge )
{
case (int) ABEdge.ABE_LEFT:
mmi.ptMaxPosition.x += 2;
mmi.ptMaxTrackSize.x -= 2;
mmi.ptMaxSize.x -= 2;
break;
case (int) ABEdge.ABE_RIGHT:
mmi.ptMaxSize.x -= 2;
mmi.ptMaxTrackSize.x -= 2;
break;
case (int) ABEdge.ABE_TOP:
mmi.ptMaxPosition.y += 2;
mmi.ptMaxTrackSize.y -= 2;
mmi.ptMaxSize.y -= 2;
break;
case (int) ABEdge.ABE_BOTTOM:
mmi.ptMaxSize.y -= 2;
mmi.ptMaxTrackSize.y -= 2;
break;
default:
return mmi;
}
return mmi;
}
private static int GetEdge (RECT rc)
{
int uEdge = -1;
if ( rc.top == rc.left && rc.bottom > rc.right )
uEdge = (int) ABEdge.ABE_LEFT;
else if ( rc.top == rc.left && rc.bottom < rc.right )
uEdge = (int) ABEdge.ABE_TOP;
else if ( rc.top > rc.left )
uEdge = (int) ABEdge.ABE_BOTTOM;
else
uEdge = (int) ABEdge.ABE_RIGHT;
return uEdge;
}
public static void WindowInitialized (Window window)
{
IntPtr handle = (new System.Windows.Interop.WindowInteropHelper(window)).Handle;
System.Windows.Interop.HwndSource.FromHwnd(handle).AddHook(new System.Windows.Interop.HwndSourceHook(WindowProc));
}
private static IntPtr WindowProc (System.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam, ref bool handled)
{
switch ( msg )
{
case 0x0024:
WmGetMinMaxInfo(hwnd, lParam);
handled = true;
break;
}
return (IntPtr) 0;
}
private static void WmGetMinMaxInfo (IntPtr hwnd, IntPtr lParam)
{
MINMAXINFO mmi = (MINMAXINFO) Marshal.PtrToStructure(lParam, typeof(MINMAXINFO));
IntPtr monitorContainingApplication = MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
if ( monitorContainingApplication != System.IntPtr.Zero )
{
MONITORINFO monitorInfo = new MONITORINFO();
GetMonitorInfo(monitorContainingApplication, monitorInfo);
RECT rcWorkArea = monitorInfo.rcWork;
RECT rcMonitorArea = monitorInfo.rcMonitor;
mmi.ptMaxPosition.x = Math.Abs(rcWorkArea.left - rcMonitorArea.left);
mmi.ptMaxPosition.y = Math.Abs(rcWorkArea.top - rcMonitorArea.top);
mmi.ptMaxSize.x = Math.Abs(rcWorkArea.right - rcWorkArea.left);
mmi.ptMaxSize.y = Math.Abs(rcWorkArea.bottom - rcWorkArea.top);
mmi.ptMaxTrackSize.x = mmi.ptMaxSize.x; //maximum drag X size for the window
mmi.ptMaxTrackSize.y = mmi.ptMaxSize.y; //maximum drag Y size for the window
mmi.ptMinTrackSize.x = 800; //minimum drag X size for the window
mmi.ptMinTrackSize.y = 600; //minimum drag Y size for the window
mmi = AdjustWorkingAreaForAutoHide(monitorContainingApplication, mmi); //need to adjust sizing if taskbar is set to autohide
}
Marshal.StructureToPtr(mmi, lParam, true);
}
public enum ABEdge
{
ABE_LEFT = 0,
ABE_TOP = 1,
ABE_RIGHT = 2,
ABE_BOTTOM = 3
}
public enum ABMsg
{
ABM_NEW = 0,
ABM_REMOVE = 1,
ABM_QUERYPOS = 2,
ABM_SETPOS = 3,
ABM_GETSTATE = 4,
ABM_GETTASKBARPOS = 5,
ABM_ACTIVATE = 6,
ABM_GETAUTOHIDEBAR = 7,
ABM_SETAUTOHIDEBAR = 8,
ABM_WINDOWPOSCHANGED = 9,
ABM_SETSTATE = 10
}
[StructLayout(LayoutKind.Sequential)]
public struct APPBARDATA
{
public int cbSize;
public IntPtr hWnd;
public int uCallbackMessage;
public int uEdge;
public RECT rc;
public bool lParam;
}
[StructLayout(LayoutKind.Sequential)]
public struct MINMAXINFO
{
public POINT ptReserved;
public POINT ptMaxSize;
public POINT ptMaxPosition;
public POINT ptMinTrackSize;
public POINT ptMaxTrackSize;
};
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public class MONITORINFO
{
public int cbSize = Marshal.SizeOf(typeof(MONITORINFO));
public RECT rcMonitor = new RECT();
public RECT rcWork = new RECT();
public int dwFlags = 0;
}
[StructLayout(LayoutKind.Sequential)]
public struct POINT
{
public int x;
public int y;
public POINT (int x, int y)
{
this.x = x;
this.y = y;
}
}
[StructLayout(LayoutKind.Sequential, Pack = 0)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
}
This works like a magic for many scenarios, like maximizing the window with no border covers the task bar as well. This solution keeps the taskbar uncovered as well.
Regards,
Umar
