C# Signature:
[DllImport("User32.dll", SetLastError=true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, uint uFlags);
Check the SWP definition on Enums.
VB.Net Signature:
<DllImport("User32.dll", SetLastError:=True)> _
Private Shared Function SetWindowPos(ByVal hWnd As IntPtr, _
ByVal hWndInsertAfter As IntPtr, _
ByVal X As Integer, _
ByVal Y As Integer, _
ByVal cx As Integer, _
ByVal cy As Integer, _
ByVal uFlags As UInteger) As Boolean
End Function
User-Defined Types:
C# Signature:
public const int SWP_ASYNCWINDOWPOS = 0x4000;
public const int SWP_DEFERERASE = 0x2000;
public const int SWP_DRAWFRAME = 0x0020;
public const int SWP_FRAMECHANGED = 0x0020;
public const int SWP_HIDEWINDOW = 0x0080;
public const int SWP_NOACTIVATE = 0x0010;
public const int SWP_NOCOPYBITS = 0x0100;
public const int SWP_NOMOVE = 0x0002;
public const int SWP_NOOWNERZORDER = 0x0200;
public const int SWP_NOREDRAW = 0x0008;
public const int SWP_NOREPOSITION = 0x0200;
public const int SWP_NOSENDCHANGING = 0x0400;
public const int SWP_NOSIZE = 0x0001;
public const int SWP_NOZORDER = 0x0004;
public const int SWP_SHOWWINDOW = 0x0040;
public const int HWND_TOP = 0;
public const int HWND_BOTTOM = 1;
public const int HWND_TOPMOST = -1;
public const int HWND_NOTOPMOST = -2;
VB.Net Signature:
Public Const SWP_NOSIZE As Integer = &H1
Public Const SWP_NOMOVE As Integer = &H2
Public Const SWP_NOZORDER As Integer = &H4
Public Const SWP_NOREDRAW As Integer = &H8
Public Const SWP_NOACTIVATE As Integer = &H10
Public Const SWP_DRAWFRAME As Integer = &H20
Public Const SWP_FRAMECHANGED As Integer = &H20
Public Const SWP_SHOWWINDOW As Integer = &H40
Public Const SWP_HIDEWINDOW As Integer = &H80
Public Const SWP_NOCOPYBITS As Integer = &H100
Public Const SWP_NOOWNERZORDER As Integer = &H200
Public Const SWP_NOREPOSITION As Integer = &H200
Public Const SWP_NOSENDCHANGING As Integer = &H400
Public Const SWP_DEFERERASE As Integer = &H2000
Public Const SWP_ASYNCWINDOWPOS As Integer = &H4000
Alternative Managed API:
Do you know one? Please contribute it!
Notes:
None.
Tips & Tricks:
Use this to hide the start menu and start bar.
Sample Code:
public void HideStartBar()
{
IntPtr handle;
try
{
// Find the handle to the Start Bar
handle = FindWindowW("HHTaskBar", null);
// If the handle is found then hide the start bar
if (handle != IntPtr.Zero)
{
// Hide the start bar
SetWindowPos(handle, 0, 0, 0, 0, 0, SWP_HIDEWINDOW);
}
}
catch
{
MessageBox.Show("Could not hide Start Bar.");
}
}
public void ShowStartBar()
{
IntPtr handle;
try
{
// Find the handle to the Start Bar
handle = FindWindowW("HHTaskBar", null);
// If the handle is found then show the start bar
if (handle != IntPtr.Zero)
{
// Show the start bar
SetWindowPos(handle, 0, 0, 0, 240, 26, SWP_SHOWWINDOW);
}
}
catch
{
MessageBox.Show("Could not show Start Bar.");
}
}
Alternate Sample
[DllImport("User32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, SetWindowPosFlags uFlags);
private const int HWND_TOP = 0;
private const int HWND_BOTTOM = 1;
private const int HWND_TOPMOST = -1;
private const int HWND_NOTOPMOST = -2;
private enum SetWindowPosFlags : uint
{
/// <summary>If the calling thread and the thread that owns the window are attached to different input queues,
/// the system posts the request to the thread that owns the window. This prevents the calling thread from
/// blocking its execution while other threads process the request.</summary>
/// <remarks>SWP_ASYNCWINDOWPOS</remarks>
SynchronousWindowPosition = 0x4000,
/// <summary>Prevents generation of the WM_SYNCPAINT message.</summary>
/// <remarks>SWP_DEFERERASE</remarks>
DeferErase = 0x2000,
/// <summary>Draws a frame (defined in the window's class description) around the window.</summary>
/// <remarks>SWP_DRAWFRAME</remarks>
DrawFrame = 0x0020,
/// <summary>Applies new frame styles set using the SetWindowLong function. Sends a WM_NCCALCSIZE message to
/// the window, even if the window's size is not being changed. If this flag is not specified, WM_NCCALCSIZE
/// is sent only when the window's size is being changed.</summary>
/// <remarks>SWP_FRAMECHANGED</remarks>
FrameChanged = 0x0020,
/// <summary>Hides the window.</summary>
/// <remarks>SWP_HIDEWINDOW</remarks>
HideWindow = 0x0080,
/// <summary>Does not activate the window. If this flag is not set, the window is activated and moved to the
/// top of either the topmost or non-topmost group (depending on the setting of the hWndInsertAfter
/// parameter).</summary>
/// <remarks>SWP_NOACTIVATE</remarks>
DoNotActivate = 0x0010,
/// <summary>Discards the entire contents of the client area. If this flag is not specified, the valid
/// contents of the client area are saved and copied back into the client area after the window is sized or
/// repositioned.</summary>
/// <remarks>SWP_NOCOPYBITS</remarks>
DoNotCopyBits = 0x0100,
/// <summary>Retains the current position (ignores X and Y parameters).</summary>
/// <remarks>SWP_NOMOVE</remarks>
IgnoreMove = 0x0002,
/// <summary>Does not change the owner window's position in the Z order.</summary>
/// <remarks>SWP_NOOWNERZORDER</remarks>
DoNotChangeOwnerZOrder = 0x0200,
/// <summary>Does not redraw changes. If this flag is set, no repainting of any kind occurs. This applies to
/// the client area, the nonclient area (including the title bar and scroll bars), and any part of the parent
/// window uncovered as a result of the window being moved. When this flag is set, the application must
/// explicitly invalidate or redraw any parts of the window and parent window that need redrawing.</summary>
/// <remarks>SWP_NOREDRAW</remarks>
DoNotRedraw = 0x0008,
/// <summary>Same as the SWP_NOOWNERZORDER flag.</summary>
/// <remarks>SWP_NOREPOSITION</remarks>
DoNotReposition = 0x0200,
/// <summary>Prevents the window from receiving the WM_WINDOWPOSCHANGING message.</summary>
/// <remarks>SWP_NOSENDCHANGING</remarks>
DoNotSendChangingEvent = 0x0400,
/// <summary>Retains the current size (ignores the cx and cy parameters).</summary>
/// <remarks>SWP_NOSIZE</remarks>
IgnoreResize = 0x0001,
/// <summary>Retains the current Z order (ignores the hWndInsertAfter parameter).</summary>
/// <remarks>SWP_NOZORDER</remarks>
IgnoreZOrder = 0x0004,
/// <summary>Displays the window.</summary>
/// <remarks>SWP_SHOWWINDOW</remarks>
ShowWindow = 0x0040,
}
void SendWPFWindowToBack(Window window)
{
IntPtr hwnd = new WindowInteropHelper(this.window).Handle;
SetWindowPos(hwnd, (IntPtr)HWND_BOTTOM, 0, 0, 0, 0,
SetWindowPosFlags.SynchronousWindowPosition |
SetWindowPosFlags.IgnoreMove |
SetWindowPosFlags.IgnoreResize);
}
