问自动调整ElementHost到其内容的大小

EN

public System.Windows.Size GetElementPixelSize(UIElement element) 
{ 
    Matrix transformToDevice; 
    var source = PresentationSource.FromVisual(element);
    if (source != null)
        transformToDevice = source.CompositionTarget.TransformToDevice;
    else     
        using (var Hwndsource = new HwndSource(new HwndSourceParameters()))
            transformToDevice = Hwndsource.CompositionTarget.TransformToDevice;


    if (element.DesiredSize == new System.Windows.Size()) 
        element.Measure(new System.Windows.Size(double.PositiveInfinity, double.PositiveInfinity)); 

    return (System.Windows.Size)transformToDevice.Transform((Vector)element.DesiredSize); 
}