public static extern int GetThemePartSize(IntPtr hTheme,
IntPtr hDC,
int partId,
int stateId,
IntPtr rect,
Win32.THEMESIZE themeSize,
ref Win32.SIZE size);
/// <summary>
/// Sets the given bitmap as window content with transparent parts via the
/// layered windows API.
/// </summary>
/// <param name="bitmap">The bitmap to set.</param>
/// <param name="opacity">The overall opacity (255 = opaque).</param>
public static void SetBitmap(Control control, Bitmap bitmap, int opacity)
{
if (bitmap.PixelFormat != PixelFormat.Format32bppArgb)
{
throw new ApplicationException("The bitmap must be 32ppp with alpha-channel.");
}
IntPtr screenDc = Win32.GetDC(IntPtr.Zero);
IntPtr memDc = Win32.CreateCompatibleDC(screenDc);
IntPtr hBitmap = IntPtr.Zero;
IntPtr oldBitmap = IntPtr.Zero;
try
{
hBitmap = bitmap.GetHbitmap(Color.FromArgb(0)); // grab a GDI handle from this GDI+ bitmap
oldBitmap = Win32.SelectObject(memDc, hBitmap);
Win32.SIZE size = new Win32.SIZE(bitmap.Width, bitmap.Height);
Win32.POINT pointSource = new Win32.POINT(0, 0);
Win32.POINT topPos = new Win32.POINT(control.Left, control.Top);
Win32.BLENDFUNCTION blend = new Win32.BLENDFUNCTION();
blend.BlendOp = Win32.AC_SRC_OVER;
blend.BlendFlags = 0;
blend.SourceConstantAlpha = (byte)opacity;
blend.AlphaFormat = Win32.AC_SRC_ALPHA;
if (!control.IsDisposed && !control.Disposing)
{
Win32.UpdateLayeredWindow(control.Handle, screenDc, ref topPos, ref size, memDc,
ref pointSource, 0, ref blend, Win32.ULW_ALPHA);
}
}
finally
{
Win32.ReleaseDC(IntPtr.Zero, screenDc);
if (hBitmap != IntPtr.Zero)
{
Win32.SelectObject(memDc, oldBitmap);
Win32.DeleteObject(hBitmap);
}
Win32.DeleteDC(memDc);
}
}
/// <summary>
/// Get the size of a themed part in a givenstate.
/// </summary>
/// <param name="g">Graphics object reference.</param>
/// <param name="part">Theme part.</param>
/// <param name="state">Theme state of part.</param>
/// <param name="themeSize">How to calculate the size.</param>
/// <returns>new Size if themed; otherwise Size.Empty</returns>
public Size GetThemePartSize(Graphics g, int part, int state, THEMESIZE themeSize)
{
Size retSize = Size.Empty;
if (IsControlThemed)
{
Win32.SIZE size = new Win32.SIZE();
IntPtr hDC = g.GetHdc();
Uxtheme.GetThemePartSize(_hTheme, hDC, part, state, IntPtr.Zero, themeSize, ref size);
g.ReleaseHdc(hDC);
// Copy back results
retSize.Width = size.cx;
retSize.Height = size.cy;
}
return(retSize);
}
/// <summary>
/// Redraws the bitmap overlay.
/// </summary>
/// <returns>True if successful, false otherwise.</returns>
protected bool RefreshBitmap()
{
// The bitmap must be 32-bit RGBA
if (_bitmap == null || _bitmap.PixelFormat != PixelFormat.Format32bppArgb)
{
return(false);
}
// Create a memory DC that's compatible with the screen
IntPtr screenDC = Win32.GetDC(IntPtr.Zero);
if (screenDC == IntPtr.Zero)
{
return(false);
}
IntPtr memDC = GDI32.CreateCompatibleDC(screenDC);
if (memDC == IntPtr.Zero)
{
Win32.ReleaseDC(IntPtr.Zero, screenDC);
return(false);
}
// Prepare to draw the bitmap
IntPtr hBitmap = IntPtr.Zero;
IntPtr oldBitmap = IntPtr.Zero;
bool success = false;
try
{
// Select the bitmap into the memory DC
hBitmap = _bitmap.GetHbitmap(Color.FromArgb(0)); // grab a GDI handle from this GDI+ bitmap
oldBitmap = GDI32.SelectObject(memDC, hBitmap);
// Call UpdateLayeredWindow to effectively blit the contents of the memory DC into the form while performing alpha blending
Win32.POINT windowTopLeft = new Win32.POINT(Left, Top);
Win32.SIZE bitmapSize = new Win32.SIZE(_bitmap.Width, _bitmap.Height);
Win32.POINT bitmapTopLeft = new Win32.POINT(0, 0);
byte blendAlpha = 0;
if (_bitmapOpacity < 0)
{
blendAlpha = 0;
}
else if (_bitmapOpacity > 1)
{
blendAlpha = 255;
}
else
{
blendAlpha = (byte)(_bitmapOpacity * 255);
}
GDI32.BLENDFUNCTION blendFunc = new GDI32.BLENDFUNCTION();
blendFunc.BlendOp = GDI32.AC_SRC_OVER;
blendFunc.BlendFlags = 0;
blendFunc.SourceConstantAlpha = blendAlpha;
blendFunc.AlphaFormat = GDI32.AC_SRC_ALPHA;
Win32.UpdateLayeredWindow(Handle, screenDC, ref windowTopLeft, ref bitmapSize, memDC, ref bitmapTopLeft, 0, ref blendFunc, Win32.ULW_ALPHA);
success = true;
}
finally
{
// Clean up the resources
if (hBitmap != IntPtr.Zero)
{
GDI32.SelectObject(memDC, oldBitmap);
GDI32.DeleteObject(hBitmap);
}
GDI32.DeleteDC(memDC);
Win32.ReleaseDC(IntPtr.Zero, screenDC);
}
return(success);
}
/// <summary>
/// Redraws the bitmap overlay.
/// </summary>
/// <returns>True if successful, false otherwise.</returns>
protected bool RefreshBitmap()
{
// The bitmap must be 32-bit RGBA
if (_bitmap == null || _bitmap.PixelFormat != PixelFormat.Format32bppArgb)
return false;
// Create a memory DC that's compatible with the screen
IntPtr screenDC = Win32.GetDC(IntPtr.Zero);
if (screenDC == IntPtr.Zero)
return false;
IntPtr memDC = GDI32.CreateCompatibleDC(screenDC);
if (memDC == IntPtr.Zero)
{
Win32.ReleaseDC(IntPtr.Zero, screenDC);
return false;
}
// Prepare to draw the bitmap
IntPtr hBitmap = IntPtr.Zero;
IntPtr oldBitmap = IntPtr.Zero;
bool success = false;
try
{
// Select the bitmap into the memory DC
hBitmap = _bitmap.GetHbitmap(Color.FromArgb(0)); // grab a GDI handle from this GDI+ bitmap
oldBitmap = GDI32.SelectObject(memDC, hBitmap);
// Call UpdateLayeredWindow to effectively blit the contents of the memory DC into the form while performing alpha blending
Win32.POINT windowTopLeft = new Win32.POINT(Left, Top);
Win32.SIZE bitmapSize = new Win32.SIZE(_bitmap.Width, _bitmap.Height);
Win32.POINT bitmapTopLeft = new Win32.POINT(0, 0);
byte blendAlpha = 0;
if (_bitmapOpacity < 0)
blendAlpha = 0;
else if (_bitmapOpacity > 1)
blendAlpha = 255;
else
blendAlpha = (byte)(_bitmapOpacity * 255);
GDI32.BLENDFUNCTION blendFunc = new GDI32.BLENDFUNCTION();
blendFunc.BlendOp = GDI32.AC_SRC_OVER;
blendFunc.BlendFlags = 0;
blendFunc.SourceConstantAlpha = blendAlpha;
blendFunc.AlphaFormat = GDI32.AC_SRC_ALPHA;
Win32.UpdateLayeredWindow(Handle, screenDC, ref windowTopLeft, ref bitmapSize, memDC, ref bitmapTopLeft, 0, ref blendFunc, Win32.ULW_ALPHA);
success = true;
}
finally
{
// Clean up the resources
if (hBitmap != IntPtr.Zero)
{
GDI32.SelectObject(memDC, oldBitmap);
GDI32.DeleteObject(hBitmap);
}
GDI32.DeleteDC(memDC);
Win32.ReleaseDC(IntPtr.Zero, screenDC);
}
return success;
}
public void SetBits(Bitmap bitmap, byte opacity)
{
if (!Bitmap.IsCanonicalPixelFormat(bitmap.PixelFormat) || !Bitmap.IsAlphaPixelFormat(bitmap.PixelFormat))
throw new ApplicationException("The bitmap must be 32 bits per pixel with an alpha channel.");
IntPtr oldBits = IntPtr.Zero;
IntPtr screenDC = Win32.GetDC(IntPtr.Zero);
IntPtr hBitmap = IntPtr.Zero;
IntPtr memDc = Win32.CreateCompatibleDC(screenDC);
Win32.POINT topLoc = new Win32.POINT(Left, Top);
Win32.SIZE bitMapSize = new Win32.SIZE(bitmap.Width, bitmap.Height);
Win32.BLENDFUNCTION blendFunc = new Win32.BLENDFUNCTION();
Win32.POINT srcLoc = new Win32.POINT(0, 0);
blendFunc.BlendOp = Win32.AC_SRC_OVER;
blendFunc.SourceConstantAlpha = opacity;
blendFunc.AlphaFormat = Win32.AC_SRC_ALPHA;
blendFunc.BlendFlags = 0;
try
{
hBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
oldBits = Win32.SelectObject(memDc, hBitmap);
Win32.UpdateLayeredWindow(Handle, screenDC, ref topLoc, ref bitMapSize, memDc, ref srcLoc, 0, ref blendFunc, Win32.ULW_ALPHA);
}
finally
{
if (hBitmap != IntPtr.Zero)
{
Win32.SelectObject(memDc, oldBits);
Win32.DeleteObject(hBitmap);
}
Win32.ReleaseDC(IntPtr.Zero, screenDC);
Win32.DeleteDC(memDc);
}
}
public static extern int DwmQueryThumbnailSourceSize(
IntPtr hThumbnailId,
ref Win32.SIZE size);
public static extern int DwmRegisterThumbnail(
IntPtr hwndDestination,
IntPtr hwndSource,
ref Win32.SIZE minimizedSize,
ref IntPtr hThumbnailId);
