CODEWITHSUNDEEP
windows-phone-7.1windows-phone-7
Derek Li
Derek Li

Reputation: 3111

Windows Phone Background image change performance issue

I'm writing a windows phone app that consist of a pivot control, and I want to change the background as I switch between different pivot items. Based on current pivot item's view model information, I will load a background that matches it.

Now what I'm doing is I have some code in onSelectionChanged handler of my pivot control:

      if (currentCondition.Contains("a"))
      {
           image = new BitmapImage(new Uri("Images/a.jpg", UriKind.Relative));
      }
      else if (currentCondition.Contains("b"))
      {
           image = new BitmapImage(new Uri("Images/b", UriKind.Relative));
      }
      ImageBrush ib = new ImageBrush();
      ib.ImageSource = image;
      this.PivotControl.Background = ib;

This did what I want but the performance is bad, when I switch between different pivot items, it will pause for about half a second to load the image.

Any suggestion on how should I approach to solve the performance problem?

Thanks!

Upvotes: 1

Views: 377

Answers (1)

ColinE
ColinE

Reputation: 70160

I am not surprised that this causes performance issues, the phone has to decode a full-screen image each time you change the background. I would suggest making your pivot control transparent, then have a 'stack' of images behind. You can then change their visibility in order to show / hide each one. For example:

<Grid>
  <Image Source="backgroundOne.jpg" Visibility="Visible"/>
  <Image Source="backgroundTwo.jpg" Visibility="Collapsed"/>

  <Pivot>
    ...
  </Pivot>
</Grid>

Upvotes: 4

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