Question

I have a ListView-derived class which creates a bunch of user controls that are Panel-derived classes that contain a few controls each, most importantly a Image control (m_labelIcon). I am setting the image source for this control dynamically to one of the PNGs in my resource:

Uri uri = new Uri("/MyApp;component/Common/Main/res/drawable/some_icon.png");
StreamResourceInfo resourceInfo = Application.GetResourceStream(uri);
BitmapImage bitmapSource = new BitmapImage();

bitmapSource.CreateOptions = BitmapCreateOptions.None;

bitmapSource.SetSource(resourceInfo.Stream);
m_labelIcon.Source = bitmapSource;

However, when the list view appears, the images are all missing. If I scroll the list to the very bottom and then back to the top, the images start appearing. I’ve specified BitmapCreateOptions.None, which should prevent delay-loading the images (they are in my resource and not on the web).

I’ve also tried using the ImageOpened event, but this doesn’t work.

Any thoughts?

Thanks,
swine

Answer 1

After hours of the debugging, I stumbled upon the simple solution. Even though I was overriding ArrangeOverride() and MeasureOverride() like so:

protected override Size MeasureOverride(Size availableSize)
{
  Size panelDesiredSize = new Size();

  double height = Math.Max(getIconSizeToUseInPixels(),
    m_labelName.DesiredSize.Height);

  panelDesiredSize = new Size(availableSize.Width, height);

  return panelDesiredSize;
}

protected override Size ArrangeOverride(Size finalSize)
{
  double x = 0;
  double y = 0;

  m_labelName.Measure(finalSize);

  double iconWidth = getIconSizeToUseInPixels();
  Size iconSize = new Size(iconWidth, iconWidth);

  double nameWidth = m_labelName.DesiredSize.Width;
  double nameHeight = m_labelName.DesiredSize.Height;

  m_labelIcon.Arrange(new Rect(
    new Point(x, y), iconSize));

  m_labelName.Arrange(new Rect(
    new Point(iconWidth, y + (finalSize.Height - nameHeight) / 2),
    new Size(nameWidth, nameHeight)));
  m_labelName.Width = nameWidth;
  m_labelName.Height = nameHeight;

  return finalSize; // Returns the final Arranged size
}

I still needed to set the Width and the Height properties of the Image control manually in the constructor of my custom control like so:

THIS FIXED THE PROBLEM:

  m_labelIcon.Width = getIconSizeToUseInPixels();
  m_labelIcon.Height = getIconSizeToUseInPixels();