双击可在WP8中缩放图像？

Question

I have an Image within a ScrollViewer and I want the image to zoom on double tap. It zooms correctly, but the problem is with the scrollviewer. I want the ScrollViewer to scroll to a the point where the user tapped. Like if the user tapped on the bottom right corner, that part would get zoomed in and the scrollviewer would scroll to bring that point to the center of the screen. Here's the code I'm using..

private void ImgHolder1_DoubleTap(object sender, System.Windows.Input.GestureEventArgs e)
{
    //If zoomed in, then zoom out
    if (isZoomed)
    {
        Img1.Width = Img1.Width / 1.5;
        Img1.Height = Img1.Height / 1.5;
        ImgHolder1.HorizontalScrollBarVisibility = ScrollBarVisibility.Disabled;
        isPowerZoomed = false;
    }
    //else zoom in
    else
    {
        Img1.Width = Img1.Width * 1.5;
        Img1.Height = Img1.Height * 1.5;
        ImgHolder1.HorizontalScrollBarVisibility = ScrollBarVisibility.Visible;
        isPowerZoomed = true;
    }

    //Scroll to offset
    Point p = e.GetPosition(sender as UIElement);
    ImgHolder1.ScrollToHorizontalOffset(p.X);
    ImgHolder1.ScrollToVerticalOffset(p.Y);
}

Anyone can help me with this?

Answer 1

看看这个： MSDN帖子