/// <summary>
/// Get cropping areas as BitmapFrame
/// </summary>
/// <returns></returns>
public BitmapFrame GetCroppedBitmapFrame()
{
var parent = VisualTreeHelper.GetParent(AdornedElement) as UIElement;
// 1) get current dpi
var pSource = PresentationSource.FromVisual(Application.Current.MainWindow);
Matrix m = pSource.CompositionTarget.TransformToDevice;
double dpiX = m.M11 * 96;
double dpiY = m.M22 * 96;
// 2) create RenderTargetBitmap
var elementBitmap = new RenderTargetBitmap(
(int)AdornedElement.RenderSize.Width,
(int)AdornedElement.RenderSize.Height,
dpiX,
dpiY,
PixelFormats.Default
);
//Important
AdornedElement.Measure(AdornedElement.RenderSize);
AdornedElement.Arrange(new Rect(AdornedElement.RenderSize));
// 3) draw element
elementBitmap.Render(AdornedElement);
if (parent != null)
{
//Important
parent.Measure(AdornedElement.RenderSize);
parent.Arrange(new Rect(AdornedElement.RenderSize));
}
var crop = new CroppedBitmap(
elementBitmap,
new Int32Rect(
(int)_rectangleManager.TopLeft.X,
(int)_rectangleManager.TopLeft.Y,
(int)_rectangleManager.RectangleWidth,
(int)_rectangleManager.RectangleHeight
)
);
return(BitmapFrame.Create(crop));
}