Stream stream = WriteableBitmap.PixelBuffer.AsStream()缺失

Question

我正在写windows store app(8.1),我有样本(可能是win 8.0):

private WriteableBitmap WriteableBitmap;
…
WriteableBitmap = new WriteableBitmap(500,500);
…
using (Stream stream = WriteableBitmap.PixelBuffer.AsStream())
{
    …
}

所以我创建了新的win 8.1项目并尝试以同样的方式完成,但是当我到达时:

using (Stream stream = WriteableBitmap.PixelBuffer.AsStream())

我的项目不认识*.AsStream()方法,谁能告诉我为什么？

Answer 1

using System.Runtime.InteropServices.WindowsRuntime;