Question

I am setting a background image on my XAML Grid with a Uri. The Uri points off to a HTTP url, where it will fetch, and then render the image as a background for a Win8 metro app.

I’ve been trying to figure out if there is an event or something I can hook into to let me know that WPF has loaded it into memory, AND finished rendering it out of view.

Currently, a small image will load fast enough, and smoothly fade in. However, if I load a larger, slower image, it will take 100s of ms to show up as the background, which means it either pops up mid-fade, or after the fade effect has completed. This looks quite poor.

The goal is to have a fade transition between app pages (I already have this), without the inconsistency of the background image popping up whenever it’s done.

Any suggestions would be welcomed.

Answer 1

You don’t say exactly how you’re loading the image but there’s a DownloadCompleted event on BitmapImage, e.g.

BitmapImage bmp = new BitmapImage(imageUri); 
bmp.DownloadCompleted += ReadyToDisplay;