unity生成WP工程后ExtendedSplashImage显示不正确的问题

<SwapChainPanel x:Name="DXSwapChainPanel">
        <Grid x:Name="ExtendedSplashGrid" >
            <Image x:Name="ExtendedSplashImage" Source="Assets/SplashScreen.png" VerticalAlignment="Center" HorizontalAlignment="Center">
                <Image.Projection> 
                    <PlaneProjection RotationZ="90"/>
                </Image.Projection>
            </Image>
        </Grid>
    </SwapChainPanel>

  private void PositionImage()
        {
            //get the current core window
            CoreWindow coreWindow = CoreWindow.GetForCurrentThread();
#if UNITY_WP_8_1
            //Windows Phone
            //That "/3" seems to do the correct placement!
            ExtendedSplashImage.Margin = new Thickness(0, -coreWindow.Bounds.Height / 3, 0, coreWindow.Bounds.Height / 3);

            ExtendedSplashGrid.Height = coreWindow.Bounds.Width;
            ExtendedSplashGrid.Width = coreWindow.Bounds.Height;
#else
//Windows Metro
            ExtendedSplashImage.SetValue(Canvas.LeftProperty, splashImageRect.X);
            ExtendedSplashImage.SetValue(Canvas.TopProperty, splashImageRect.Y);
            ExtendedSplashImage.Height = splashImageRect.Height;
            ExtendedSplashImage.Width = splashImageRect.Width;
 
#endif

        }