SilverLight 截取bingying地图保存为图片byte[]类型，出现错误：WriteableBitmap 已对内容进行保护。不允许访问像素。求解！

hrangelet 2012-10-14 05:13:35

void mis_Click(object sender, RoutedEventArgs e) { WriteableBitmap bitmap = new WriteableBitmap(LayoutRoot, new MatrixTransform()); Image imgs = new Image(); imgs.Source = bitmap; ImageData = SaveToByteArray(bitmap); }//将WriteableBitmap保存为byte[]数组
public byte[] SaveToByteArray(WriteableBitmap bitmap)
{
int width = bitmap.PixelWidth;
int height = bitmap.PixelHeight;
int bands = 3;
byte[][,] raster = new byte[bands][,];
for (int i = 0; i < bands; i++)
{
raster[i] = new byte[width, height];
}
for (int row = 0; row < height; row++)
{
for (int column = 0; column < width; column++)
{
int pixel = bitmap.Pixels[width * row + column];
raster[0][column, row] = (byte)(pixel >> 16);
raster[1][column, row] = (byte)(pixel >> 8);
raster[2][column, row] = (byte)pixel;
}
}
FluxJpeg.Core.ColorModel model =
new FluxJpeg.Core.ColorModel { colorspace = FluxJpeg.Core.ColorSpace.RGB };
FluxJpeg.Core.Image img = new FluxJpeg.Core.Image(model, raster);
//Encode the Image as a JPEG
MemoryStream stream = new MemoryStream();
FluxJpeg.Core.Encoder.JpegEncoder encoder =
new FluxJpeg.Core.Encoder.JpegEncoder(img, 100, stream);
encoder.Encode();
//Back to the start
stream.Seek(0, SeekOrigin.Begin);
//获取byte[]数组
//读二进制的长度
int readSize = 204800;
byte[] buffer = new Byte[readSize];
int byteRead = stream.Read(buffer, 0, readSize);
byte[] setData = new Byte[byteRead];
setData = buffer;
return setData;
}代码行： int pixel = bitmap.Pixels[width * row + column];报错网上查了资料，都说得太模糊，请问有大神做过类似例子吗？求个demo或者解决方案！

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