"This stream does not support seek operations" 正在制作 HTTPWebRequest

Question

我有这样一段代码：

var uri = "myURL.com"
var request = (HttpWebRequest)WebRequest.Create(uri);
string postData = "myData";
byte[] data = Encoding.UTF8.GetBytes(postData);

request.Method = "POST";
request.UseDefaultCredentials = true;
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
request.AddRange(1024);
request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.82 Safari/537.36";

Stream stream = request.GetRequestStream();
stream.Write(data, 0, data.Length);
WebResponse response = request.GetResponse();
Console.WriteLine(((HttpWebResponse)response).StatusDescription);
string responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
Console.WriteLine(responseString);
response.Close();
stream.Close();

我得到一个异常，如："This stream does not support seek operations"。此错误发生在 stream.Length 和 stream.Position 中。我虽然认为，由于这个错误，我的 postData 没有发送到服务器。 Here is the screenshot of the exception

Answer 1

仅当您调用与当前流（在您的情况下为 NetworkStream）不兼容的方法或属性时才会抛出此异常。如果需要向后移动，则需要将内容复制到临时流（MemoryStream、FileStream 等）中。

您的示例代码在这种情况下没有问题。您在 Visual studio 中看到的异常是因为 VS 尝试访问每个属性以显示一个值。当您的代码运行时，不会调用 'Position' 等属性，一切都很好。

以编程方式了解您是否可以在流中查找。使用流的属性 CanSeek。

"This stream does not support seek operations" 正在制作 HTTPWebRequest

"This stream does not support seek operations" while HTTPWebRequest making

c#

stream

httpwebrequest