Windows Phone 7.8宽幅图像不工作

我已经尝试了下面两种解决方案，它们都有相同的结果。创建了磁贴，但没有显示图像。我能够设置标题和其他属性，但当我使用这个解决方案时，它不起作用。我已经验证了映像路径，并且它在构建中。什么好主意吗?

public static void UpdateFlipTile(
            Uri wideBackgroundImage, 
            Uri wideBackBackgroundImage)
{
   if (IsTargetedVersion)
   {
  // Get the new FlipTileData type.
  Type flipTileDataType = Type.GetType("Microsoft.Phone.Shell.FlipTileData, Microsoft.Phone");
  // Get the ShellTile type so we can call the new version of "Update" that takes the new Tile templates.
  Type shellTileType = Type.GetType("Microsoft.Phone.Shell.ShellTile, Microsoft.Phone");
  // Loop through any existing Tiles that are pinned to Start.
  foreach (var tileToUpdate in ShellTile.ActiveTiles)
  {
     // Look for a match based on the Tile's NavigationUri (tileId).
        // Get the constructor for the new FlipTileData class and assign it to our variable to hold the Tile properties.
        var UpdateTileData = flipTileDataType.GetConstructor(new Type[] { }).Invoke(null);
        // Set the properties. 
        SetProperty(UpdateTileData, "WideBackgroundImage", wideBackgroundImage);
        SetProperty(UpdateTileData, "WideBackBackgroundImage", wideBackBackgroundImage);

        // Invoke the new version of ShellTile.Update.
        shellTileType.GetMethod("Update").Invoke(tileToUpdate, new Object[] { UpdateTileData });
            break;
      }
   }
}
private static void SetProperty(object instance, string name, object value)
{
   var setMethod = instance.GetType().GetProperty(name).GetSetMethod();
   setMethod.Invoke(instance, new object[] { value });
}

我也试过这个解决方案

    if (Environment.OSVersion.Version >= new Version(7, 10, 8858))
{
    var tile = ShellTile.ActiveTiles.First();
    var flipTileData = new FlipTileData
            {
                BackgroundImage = new Uri("/Icons/MediumLogo.png", UriKind.RelativeOrAbsolute),
                WideBackgroundImage = new Uri("/Icons/WideLogo.png", UriKind.RelativeOrAbsolute),
            };
    tile.Update(flipTileData);
}