Using this method, I want to render a canvas to a bitmap.
When I add a Shape
to the Canvas
, it is rendered twice the specified size.
In the example below, I am drawing a line from (0;0) to (50;50) on a canvas of size 200 by 200.
public bool exportToBmp(string path, int dpi = 96)
{
if (path == null)
return false;
var canvas = new System.Windows.Controls.Canvas();
// This diagonal Line should span a quarter of the rendered Image
var myLine = new System.Windows.Shapes.Line();
myLine.Stroke = System.Windows.Media.Brushes.LightSteelBlue;
myLine.X1 = 0;
myLine.X2 = 50;
myLine.Y1 = 0;
myLine.Y2 = 50;
myLine.StrokeThickness = 2;
canvas.Children.Add(myLine);
canvas.Height = 200;
canvas.Width = 200;
Size size = new Size(canvas.Width, canvas.Height);
canvas.Measure(size);
canvas.Arrange(new Rect(size));
var width = (int)canvas.ActualWidth;
var height = (int)canvas.ActualHeight;
RenderTargetBitmap bmp = new RenderTargetBitmap(width, height, dpi, dpi, PixelFormats.Pbgra32);
bmp.Render(canvas);
PngBitmapEncoder image = new PngBitmapEncoder();
image.Frames.Add(BitmapFrame.Create(bmp));
using (Stream fs = File.Create(path))
{
image.Save(fs);
}
return false;
}
The rendered image I get is 200 by 200 px big, but the diagonal goes all the way to (100;100)
What am I doing wrong?