/// <summary>
/// Helper function to capture a bitmap for a given window handle or incase of WPF app,
/// an UIElement.
/// </summary>
/// <param name="taskbarWindow">The proxy window for which a bitmap needs to be created</param>
/// <param name="requestedSize">Size for the requested bitmap image</param>
/// <returns>Bitmap captured from the window handle or UIElement. Null if the window is hidden or it's size is zero.</returns>
private static IntPtr GrabBitmap(TaskbarWindow taskbarWindow, System.Drawing.Size requestedSize)
{
IntPtr hBitmap = IntPtr.Zero;
if (taskbarWindow.TabbedThumbnail.WindowHandle != IntPtr.Zero) //TabbedThumbnail is linked to WinformsControl
{
if (taskbarWindow.TabbedThumbnail.CurrentHBitmap == IntPtr.Zero)
{
using (Bitmap bmp = TabbedThumbnailScreenCapture.GrabWindowBitmap(
taskbarWindow.TabbedThumbnail.WindowHandle, requestedSize)) {
hBitmap = bmp.GetHbitmap();
}
}
else
{
using (Image img = Image.FromHbitmap(taskbarWindow.TabbedThumbnail.CurrentHBitmap)) {
using (Bitmap bmp = new Bitmap(img, requestedSize)) {
hBitmap = bmp != null?bmp.GetHbitmap() : IntPtr.Zero;
}
}
}
}
else if (taskbarWindow.TabbedThumbnail.WindowsControl != null) //TabbedThumbnail is linked to a WPF UIElement
{
if (taskbarWindow.TabbedThumbnail.CurrentHBitmap == IntPtr.Zero)
{
Bitmap bmp = TabbedThumbnailScreenCapture.GrabWindowBitmap(
taskbarWindow.TabbedThumbnail.WindowsControl,
96, 96, requestedSize.Width, requestedSize.Height);
if (bmp != null)
{
hBitmap = bmp.GetHbitmap();
bmp.Dispose();
}
}
else
{
using (Image img = Image.FromHbitmap(taskbarWindow.TabbedThumbnail.CurrentHBitmap)) {
using (Bitmap bmp = new Bitmap(img, requestedSize)) {
hBitmap = bmp != null?bmp.GetHbitmap() : IntPtr.Zero;
}
}
}
}
return(hBitmap);
}
private static bool DispatchSendIconThumbnailMessage(ref System.Windows.Forms.Message m, TaskbarWindow taskbarWindow)
{
if (m.Msg == (int)TaskbarNativeMethods.WmDwmSendIconThumbnail)
{
int width = (int)((long)m.LParam >> 16);
int height = (int)(((long)m.LParam) & (0xFFFF));
Size requestedSize = new Size(width, height);
// Fire an event to let the user update their bitmap
taskbarWindow.TabbedThumbnail.OnTabbedThumbnailBitmapRequested();
IntPtr hBitmap = IntPtr.Zero;
// Default size for the thumbnail
Size realWindowSize = new Size(200, 200);
// Get the size of teh control or UIElement
if (taskbarWindow.TabbedThumbnail.WindowHandle != IntPtr.Zero)
{
TabbedThumbnailNativeMethods.GetClientSize(taskbarWindow.TabbedThumbnail.WindowHandle, out realWindowSize);
}
else if (taskbarWindow.TabbedThumbnail.WindowsControl != null)
{
realWindowSize = new Size(
Convert.ToInt32(taskbarWindow.TabbedThumbnail.WindowsControl.RenderSize.Width),
Convert.ToInt32(taskbarWindow.TabbedThumbnail.WindowsControl.RenderSize.Height));
}
if (realWindowSize.Height == -1 && realWindowSize.Width == -1)
{
realWindowSize.Width = realWindowSize.Height = 199;
}
// capture the bitmap for the given control
// If the user has already specified us a bitmap to use, use that.
if (taskbarWindow.TabbedThumbnail.ClippingRectangle != null &&
taskbarWindow.TabbedThumbnail.ClippingRectangle.Value != Rectangle.Empty)
{
if (taskbarWindow.TabbedThumbnail.CurrentHBitmap == IntPtr.Zero)
{
hBitmap = GrabBitmap(taskbarWindow, realWindowSize);
}
else
{
hBitmap = taskbarWindow.TabbedThumbnail.CurrentHBitmap;
}
// Clip the bitmap we just got.
Bitmap bmp = Bitmap.FromHbitmap(hBitmap);
Rectangle clippingRectangle = taskbarWindow.TabbedThumbnail.ClippingRectangle.Value;
// If our clipping rect is out of bounds, update it
if (clippingRectangle.Height > requestedSize.Height)
{
clippingRectangle.Height = requestedSize.Height;
}
if (clippingRectangle.Width > requestedSize.Width)
{
clippingRectangle.Width = requestedSize.Width;
}
// NOTE: Is this a memory leak?
bmp = bmp.Clone(clippingRectangle, bmp.PixelFormat);
// Make sure we dispose the bitmap before assigning, otherwise we'll have a memory leak
if (hBitmap != IntPtr.Zero && taskbarWindow.TabbedThumbnail.CurrentHBitmap == IntPtr.Zero)
{
ShellNativeMethods.DeleteObject(hBitmap);
}
hBitmap = bmp.GetHbitmap();
bmp.Dispose();
}
else
{
// Else, user didn't want any clipping, if they haven't provided us a bitmap,
// use the screencapture utility and capture it.
hBitmap = taskbarWindow.TabbedThumbnail.CurrentHBitmap;
// If no bitmap, capture one using the utility
if (hBitmap == IntPtr.Zero)
{
hBitmap = GrabBitmap(taskbarWindow, realWindowSize);
}
}
// Only set the thumbnail if it's not null.
// If it's null (either we didn't get the bitmap or size was 0),
// let DWM handle it
if (hBitmap != IntPtr.Zero)
{
Bitmap temp = TabbedThumbnailScreenCapture.ResizeImageWithAspect(
hBitmap, requestedSize.Width, requestedSize.Height, true);
if (taskbarWindow.TabbedThumbnail.CurrentHBitmap == IntPtr.Zero)
{
ShellNativeMethods.DeleteObject(hBitmap);
}
hBitmap = temp.GetHbitmap();
TabbedThumbnailNativeMethods.SetIconicThumbnail(taskbarWindow.WindowToTellTaskbarAbout, hBitmap);
temp.Dispose();
}
// If the bitmap we have is not coming from the user (i.e. we created it here),
// then make sure we delete it as we don't need it now.
if (taskbarWindow.TabbedThumbnail.CurrentHBitmap == IntPtr.Zero)
{
ShellNativeMethods.DeleteObject(hBitmap);
}
return(true);
}
return(false);
}
