There is no built-in support for pausing the download. Why do you need to pause the download?
Check the source code. You can set Tracker.CurrentLength = Tracker.TotalLength. This will stop the download. You can later call Download again and it will be resumed.
Thank you so much
@Erel
I really appreciate your help.
I have a problem, surele it's my fault but when the downloads start and I back to the MainPage, the downloads is still running (it's ok) but when I back to the download page, they resume but in a strange form and when I tried to uncompress the downloads (they are zips) It seems that header file is corrupted, but if the program starts to download the files and I kill the app and back again to the downloads page, everything starts correctly and the files aren't corrupted.
Sorry for my English. It is for that reason I want to stop the downloads and resume again when the page appears again.
Cheers and thank you so much indeed for your help.