c# 中的 Stream CopyTo() 方法无法正常工作

Stream CopyTo() method in c# not working as I want it to

我做错了什么?。下面是我的代码片段:

PhotoResult e;
using (var filebytes = new MemoryStream())
            {
                    e.ChosenPhoto.CopyTo(filebytes);

                    Debug.WriteLine(e.ChosenPhoto.Length); // Outputs the correct length
                    Debug.WriteLine(filebytes.Length);  //Outputs 0

              }

很可能,您需要在执行复制之前重置 e.ChosenPhoto 的位置:

e.ChosenPhoto.Position = 0;

The documentation 状态:

Copying begins at the current position in the current stream