Trouble free memory

See more:

C#

WPF

Hello, at first I introduce myself, I'm Martin of Argentina, is the first time I do a query in the forum. I do not write very well in English, so I apologize.

I want to see if it is feasible to help me with a problem I have.
Using C # and Wpf.

When loading an image, the first time that passes here works perfectly, the second longer. As I can clean the variables to be re-run the entire code if you pass a second time.

void LoadImageAsyn(string uri)
               {
                   StatusPrompt.Content = "Descargando";
                   PreviewImage.Source = null;
                   bindingContext.Image = null;
                   TopContentArea.IsEnabled = false;

                   Uri u = new Uri(uri, UriKind.RelativeOrAbsolute);
                   BitmapImage img = new BitmapImage(u);
                   img.DownloadCompleted += new EventHandler(ImageDownloadCompleted);
                   img.DownloadFailed += new EventHandler<ExceptionEventArgs>(ImageDownloadFailed);
               }

Try to fix it by adding:

img.BeginInit ();
img.CacheOption = BitmapCacheOption.OnLoad;
img.EndInit ();

But tampocome funcinó. I can provide a little of your time and give me guidance on the problem that I present.

From already thank you very much.