/// <summary>
/// This code is required to set the correct window region during the resize of the Form at design time.
/// There is case when the form contains a MainMenu and also has IsMdiContainer property set, in which, the MdiClient fails to
/// resize and hence draw the correct backcolor.
/// </summary>
private void SetWindowRgn()
{
IntPtr rgn1 = IntPtr.Zero;
IntPtr rgn2 = IntPtr.Zero;
NativeMethods.RECT rect = new NativeMethods.RECT();
CreateParams cp = CreateParams;
AdjustWindowRectEx(ref rect, cp.Style, false, cp.ExStyle);
Rectangle bounds = Bounds;
rgn1 = SafeNativeMethods.CreateRectRgn(0, 0, bounds.Width, bounds.Height);
try
{
rgn2 = SafeNativeMethods.CreateRectRgn(-rect.left, -rect.top,
bounds.Width - rect.right, bounds.Height - rect.bottom);
try
{
if (rgn1 == IntPtr.Zero || rgn2 == IntPtr.Zero)
{
throw new InvalidOperationException(SR.ErrorSettingWindowRegion);
}
if (SafeNativeMethods.CombineRgn(new HandleRef(null, rgn1), new HandleRef(null, rgn1), new HandleRef(null, rgn2), NativeMethods.RGN_DIFF) == 0)
{
throw new InvalidOperationException(SR.ErrorSettingWindowRegion);
}
if (UnsafeNativeMethods.SetWindowRgn(new HandleRef(this, Handle), new HandleRef(null, rgn1), true) == 0)
{
throw new InvalidOperationException(SR.ErrorSettingWindowRegion);
}
else
{
// The hwnd now owns the region.
rgn1 = IntPtr.Zero;
}
}
finally
{
if (rgn2 != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(new HandleRef(null, rgn2));
}
}
}
finally
{
if (rgn1 != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(new HandleRef(null, rgn1));
}
}
}
private void InvalidateNonClient()
{
if (!IsPopupTextBox)
{
return;
}
NativeMethods.RECT absoluteClientRectangle = AbsoluteClientRECT;
HandleRef hNonClientRegion = NativeMethods.NullHandleRef;
HandleRef hClientRegion = NativeMethods.NullHandleRef;
HandleRef hTotalRegion = NativeMethods.NullHandleRef;
try {
// get the total client area, then exclude the client by using XOR
hTotalRegion = new HandleRef(this, SafeNativeMethods.CreateRectRgn(0, 0, this.Width, this.Height));
hClientRegion = new HandleRef(this, SafeNativeMethods.CreateRectRgn(absoluteClientRectangle.left, absoluteClientRectangle.top, absoluteClientRectangle.right, absoluteClientRectangle.bottom));
hNonClientRegion = new HandleRef(this, SafeNativeMethods.CreateRectRgn(0, 0, 0, 0));
SafeNativeMethods.CombineRgn(hNonClientRegion, hTotalRegion, hClientRegion, NativeMethods.RGN_XOR);
// Call RedrawWindow with the region.
NativeMethods.RECT ignored = new NativeMethods.RECT();
SafeNativeMethods.RedrawWindow(new HandleRef(this, Handle),
ref ignored, hNonClientRegion,
NativeMethods.RDW_INVALIDATE | NativeMethods.RDW_ERASE |
NativeMethods.RDW_UPDATENOW | NativeMethods.RDW_ERASENOW |
NativeMethods.RDW_FRAME);
}
finally {
// clean up our regions.
try {
if (hNonClientRegion.Handle != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(hNonClientRegion);
}
}
finally {
try {
if (hClientRegion.Handle != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(hClientRegion);
}
}
finally {
if (hTotalRegion.Handle != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(hTotalRegion);
}
}
}
}
}
public DCMapping(HandleRef hDC, Rectangle bounds)
{
if (hDC.Handle == IntPtr.Zero)
{
throw new ArgumentNullException("hDC");
}
bool success;
NativeMethods.POINT viewportOrg = new NativeMethods.POINT();
HandleRef hOriginalClippingRegion = NativeMethods.NullHandleRef;
NativeMethods.RegionFlags originalRegionType = NativeMethods.RegionFlags.NULLREGION;
this.translatedBounds = bounds;
this.graphics = null;
this.dc = DeviceContext.FromHdc(hDC.Handle);
this.dc.SaveHdc();
// Retrieve the x-coordinates and y-coordinates of the viewport origin for the specified device context.
success = SafeNativeMethods.GetViewportOrgEx(hDC, viewportOrg);
Debug.Assert(success, "GetViewportOrgEx() failed.");
// Create a new rectangular clipping region based off of the bounds specified, shifted over by the x & y specified in the viewport origin.
HandleRef hClippingRegion = new HandleRef(null, SafeNativeMethods.CreateRectRgn(viewportOrg.x + bounds.Left, viewportOrg.y + bounds.Top, viewportOrg.x + bounds.Right, viewportOrg.y + bounds.Bottom));
Debug.Assert(hClippingRegion.Handle != IntPtr.Zero, "CreateRectRgn() failed.");
try
{
// Create an empty region oriented at 0,0 so we can populate it with the original clipping region of the hDC passed in.
hOriginalClippingRegion = new HandleRef(this, SafeNativeMethods.CreateRectRgn(0, 0, 0, 0));
Debug.Assert(hOriginalClippingRegion.Handle != IntPtr.Zero, "CreateRectRgn() failed.");
// Get the clipping region from the hDC: result = {-1 = error, 0 = no region, 1 = success} per MSDN
int result = SafeNativeMethods.GetClipRgn(hDC, hOriginalClippingRegion);
Debug.Assert(result != -1, "GetClipRgn() failed.");
// Shift the viewpoint origint by coordinates specified in "bounds".
NativeMethods.POINT lastViewPort = new NativeMethods.POINT();
success = SafeNativeMethods.SetViewportOrgEx(hDC, viewportOrg.x + bounds.Left, viewportOrg.y + bounds.Top, lastViewPort);
Debug.Assert(success, "SetViewportOrgEx() failed.");
if (result != 0)
{
// Get the origninal clipping region so we can determine its type (we'll check later if we've restored the region back properly.)
NativeMethods.RECT originalClipRect = new NativeMethods.RECT();
originalRegionType = (NativeMethods.RegionFlags)SafeNativeMethods.GetRgnBox(hOriginalClippingRegion, ref originalClipRect);
Debug.Assert(originalRegionType != NativeMethods.RegionFlags.ERROR, "ERROR returned from SelectClipRgn while selecting the original clipping region..");
if (originalRegionType == NativeMethods.RegionFlags.SIMPLEREGION)
{
// Find the intersection of our clipping region and the current clipping region (our parent's)
// Returns a NULLREGION, the two didn't intersect.
// Returns a SIMPLEREGION, the two intersected
// Resulting region (stuff that was in hOriginalClippingRegion AND hClippingRegion is placed in hClippingRegion
NativeMethods.RegionFlags combineResult = (NativeMethods.RegionFlags)SafeNativeMethods.CombineRgn(hClippingRegion, hClippingRegion, hOriginalClippingRegion, NativeMethods.RGN_AND);
Debug.Assert((combineResult == NativeMethods.RegionFlags.SIMPLEREGION) ||
(combineResult == NativeMethods.RegionFlags.NULLREGION),
"SIMPLEREGION or NULLREGION expected.");
}
}
else
{
// If there was no clipping region, then the result is a simple region.
// We don't need to keep track of the original now, since it is empty.
SafeNativeMethods.DeleteObject(hOriginalClippingRegion);
hOriginalClippingRegion = new HandleRef(null, IntPtr.Zero);
originalRegionType = NativeMethods.RegionFlags.SIMPLEREGION;
}
// Select the new clipping region; make sure it's a SIMPLEREGION or NULLREGION
NativeMethods.RegionFlags selectResult = (NativeMethods.RegionFlags)SafeNativeMethods.SelectClipRgn(hDC, hClippingRegion);
Debug.Assert((selectResult == NativeMethods.RegionFlags.SIMPLEREGION ||
selectResult == NativeMethods.RegionFlags.NULLREGION),
"SIMPLEREGION or NULLLREGION expected.");
}
catch (Exception ex)
{
if (ClientUtils.IsSecurityOrCriticalException(ex))
{
throw;
}
this.dc.RestoreHdc();
this.dc.Dispose();
}
finally {
// Delete the new clipping region, as the clipping region for the HDC is now set
// to this rectangle. Hold on to hOriginalClippingRegion, as we'll need to restore
// it when this object is disposed.
success = SafeNativeMethods.DeleteObject(hClippingRegion);
Debug.Assert(success, "DeleteObject(hClippingRegion) failed.");
if (hOriginalClippingRegion.Handle != IntPtr.Zero)
{
success = SafeNativeMethods.DeleteObject(hOriginalClippingRegion);
Debug.Assert(success, "DeleteObject(hOriginalClippingRegion) failed.");
}
}
}