windows手机中未捕获WebBrowser

我正在使用以下代码来捕获屏幕。但页面中的浏览器不会被捕获。

WriteableBitmap w = new System.Windows.Media.Imaging.WriteableBitmap(this, null); // 'this' is your current page
WriteableBitmap w2 = new System.Windows.Media.Imaging.WriteableBitmap(480, 800);
// space for SysTray
for (int i = 0; i < 32; i++)
{
            for (int j = 0; j < 480; j++)
            {
                w2.Pixels[i * 480 + j] = -16777216; // black #ff000000
            }
}
// actual client area
for (int i = 32; i < 728; i++)
{
            for (int j = 0; j < 480; j++)
            {
                w2.Pixels[i * 480 + j] = w.Pixels[(i - 32) * 480 + j];
            }
}
// space for AppBar
for (int i = 728; i < 800; i++)
{
            for (int j = 0; j < 480; j++)
            {
                w2.Pixels[i * 480 + j] = -16777216; // black #ff000000
            }
}
MemoryStream ms = new MemoryStream();
w2.SaveJpeg(ms, 480, 800, 0, 100);
Microsoft.Xna.Framework.Media.MediaLibrary lib = new Microsoft.Xna.Framework.Media.MediaLibrary();
ms.Position = 0;
lib.SavePicture("screenshot", ms);