C# How to convert MessageBodyStream to MemoryStream?

　　　　通过WCF服务从数据库取文档数据时，返回的是Stream对象，在DevExpress的PDFViewer显示时，用PDFViewer.LoadDocunent(Stream stream);方法时，报无法从MessageBodyStream转为Stream 的错误。

　　　　最后在StackOverFlow上找到了答案。

不能通过转型，只能通过从Stream中读出数据，然后写入到MemoryStream的方法。

　　

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I am returning a Stream from a WCF Service and trying to convert it to a MemoryStream.But in the web application where in consume the WCF service,I am getting the result as of "MessageBodyStream" where i was expecting "System.IO.Stream". How can i convert this to a MemoryStream ?

　　　　 下面是采纳的回答：

　　　　Sometimes the streams come in and you dont know how big they are, for that use this code:

public static byte[] ReadToEnd(System.IO.Stream stream)
{
    long originalPosition = stream.Position;

    byte[] readBuffer = new byte[4096];

    int totalBytesRead = 0;
    int bytesRead;

    while ((bytesRead = stream.Read(readBuffer, totalBytesRead, readBuffer.Length - totalBytesRead)) > 0)
    {
        totalBytesRead += bytesRead;

        if (totalBytesRead == readBuffer.Length)
        {
            int nextByte = stream.ReadByte();
            if (nextByte != -1)
            {
                byte[] temp = new byte[readBuffer.Length * 2];
                Buffer.BlockCopy(readBuffer, 0, temp, 0, readBuffer.Length);
                Buffer.SetByte(temp, totalBytesRead, (byte)nextByte);
                readBuffer = temp;
                totalBytesRead++;
            }
        }
    }

    byte[] buffer = readBuffer;
    if (readBuffer.Length != totalBytesRead)
    {
        buffer = new byte[totalBytesRead];
        Buffer.BlockCopy(readBuffer, 0, buffer, 0, totalBytesRead);
    }
    return buffer;
}

Then once you have the byte array you can convert it to a memory stream...

  byte[] myBytes = ReadToEnd(theStream);
    Stream theMemStream = new MemoryStream(myBytes, 0, myBytes.Length);