xna - why cant i see the bitmap class while adding photos through photoChooser

I am trying to add photos to my game through photochooser. I am using all the right usings (images, shell, etc.) but can't get to the bitmap class What am I missing?

Update:

I tried using System.Windows.Media.Imaging. and still can't find the bitmapimage class. 开发者_高级运维I can't find using System.Windows.dll. can you be more specific? I get a sgwigly line below bitmapImage.

void photoChooserTask_Completed(object sender, PhotoResult result)

        {
           if (result.TaskResult == TaskResult.OK)
            {
                var bitmapImage=new 
                System.Windows.Media.Imaging.BitmapImage bmp =
             new System.Windows.Media.Imaging.BitmapImage();
                bmp.SetSource(result.ChosenPhoto);

            }         
        }

If you're trying to use System.Bitmap then this isn't supported on the phone.

You probably want System.Windows.Media.Imaging.BitmapImage (in System.Windows.dll) instead.