Question

I am trying to render a string over an image chosen by user via Photochooser task. I have seen various replies to similar question but none of the replies have nailed it.

This is what I have come up with –

void photochoosertask_Completed(object sender, PhotoResult e)
        {
            if (e.TaskResult == TaskResult.OK)
            {
System.Windows.Media.Imaging.BitmapImage bmp = new System.Windows.Media.Imaging.BitmapImage();
                bmp.SetSource(e.ChosenPhoto);
                image1.Source = bmp;



                string steamer = "SO!";
                System.Windows.Media.Imaging.WriteableBitmap bmps = new System.Windows.Media.Imaging.WriteableBitmap(bmp);
                RenderString(bmps, steamer);




            }



        }
        private void RenderString(System.Windows.Media.Imaging.WriteableBitmap bitmap, string steamer)
        {


            textBlock1.Text = steamer;



            bitmap.Render(textBlock1 , null);

            bitmap.Invalidate();

        }
    }

The code however doesn’t work. I am most likely doing a major mistake. Any help appreciated, thanks!

Answer 1

I just figured it out. Thought I should post the solution code here, might help somebody – someday 🙂

//setup a writeable bitmap with required dimensions
System.Windows.Media.Imaging.WriteableBitmap wbmps = new System.Windows.Media.Imaging.WriteableBitmap(x,y);
//set up a transform, we'll use ScaleTransform and we'll keep things simple here, 1x on both the axis 
 ScaleTransform transform = new System.Windows.Media.ScaleTransform();
 transform.ScaleX=1;
 transform.ScaleY=1; 
//now we need to render the image on the writeablebitmap and follow it up by rendering a //string
wbmps.Render(imageelement,transform);
//Now render the string which is equivalent to TextBlock.Text
wbmps.Render(texblock,transform);
//Finally - redraw the writeablebitmap to complete the rendering
wbmps.Invalidate();