public void center_image()
{
if (the_image.Source != null)
{
the_image.UpdateLayout();
contribution_canvas.UpdateLayout();
var matrix = ((MatrixTransform)contribution_canvas.RenderTransform).Matrix;
matrix.OffsetX = matrix.OffsetX + (contribution_canvas.ActualWidth / 2) - (the_image.ActualWidth / 2);
matrix.OffsetY = matrix.OffsetY + (contribution_canvas.ActualHeight / 2) - (the_image.ActualHeight / 2);
the_image.RenderTransform = new MatrixTransform(matrix);
}
//if (item.is_video)
//{
//the_media.UpdateLayout();
//contribution_canvas.UpdateLayout();
//var matrix = ((MatrixTransform)contribution_canvas.RenderTransform).Matrix;
//matrix.OffsetX = matrix.OffsetX + (contribution_canvas.ActualWidth / 2) - (the_media.Width / 2);
//matrix.OffsetY = matrix.OffsetY + (contribution_canvas.ActualHeight / 2) - (the_media.Height / 2);
//the_media.RenderTransform = new MatrixTransform(matrix);
//}
}