private void RenderImage(IImage image)
{
IntPtr imageToRender = IntPtr.Zero;
Size imageToRenderSize = emptySize;
if (null != image)
{
imageToRender = image.Bitmap.GetHbitmap();
imageToRenderSize = image.Size;
}
lock (_imageToRenderLock)
{
if (IntPtr.Zero != _imageToRender)
{
GDI.DeleteObject(_imageToRender);
}
_imageToRender = imageToRender;
_imageToRenderSize = imageToRenderSize;
}
using (Graphics g = pictureBox.CreateGraphics())
pictureBoxPaint(g, pictureBox.ClientRectangle);
}
private void pictureBoxPaint(Graphics g, Rectangle clipRectange)
{
lock (_imageToRenderLock)
{
if (IntPtr.Zero != _imageToRender)
{
Rectangle viewRec = pictureBox.ClientRectangle;
Size imageSz = _imageToRenderSize;
int x = 0;
int y = 0;
int w = viewRec.Width;
int h = (imageSz.Height * viewRec.Width) / imageSz.Width;
if (h > viewRec.Height)
{
w = (imageSz.Width * viewRec.Height) / imageSz.Height;
h = viewRec.Height;
x = (viewRec.Width - w) / 2;
}
else
{
y = (viewRec.Height - h) / 2;
}
if (x > 0)
{
Rectangle rec = new Rectangle(viewRec.Left, viewRec.Top, viewRec.Left + x, viewRec.Bottom);
rec.Intersect(clipRectange);
if (!rec.IsEmpty)
{
g.FillRectangle(SystemBrushes.ControlDark, rec);
}
rec = new Rectangle(viewRec.Left + x + w, viewRec.Top, viewRec.Right, viewRec.Bottom);
rec.Intersect(clipRectange);
if (!rec.IsEmpty)
{
g.FillRectangle(SystemBrushes.ControlDark, rec);
}
}
if (y > 0)
{
Rectangle rec = new Rectangle(viewRec.Left, viewRec.Top, viewRec.Right, viewRec.Top + y);
rec.Intersect(clipRectange);
if (!rec.IsEmpty)
{
g.FillRectangle(SystemBrushes.ControlDark, rec);
}
rec = new Rectangle(viewRec.Left, viewRec.Top + y + h, viewRec.Right, viewRec.Bottom);
rec.Intersect(clipRectange);
if (!rec.IsEmpty)
{
g.FillRectangle(SystemBrushes.ControlDark, rec);
}
}
IntPtr destHdc = g.GetHdc();
IntPtr srcHdc = GDI.CreateCompatibleDC(destHdc);
IntPtr prevBmp = GDI.SelectObject(srcHdc, _imageToRender);
GDI.StretchBlt(destHdc, viewRec.Left + x, viewRec.Top + y, w, h,
srcHdc, 0, 0, imageSz.Width, imageSz.Height, GDI.TernaryRasterOperations.SRCCOPY);
GDI.SelectObject(srcHdc, prevBmp);
GDI.DeleteDC(srcHdc);
g.ReleaseHdc(destHdc);
}
}
}
