错误(HttpWebRequest):写入流的字节超过指定的Content-Length字节大小

本文关键字：字节 Content-Length 错误 HttpWebRequest | 更新日期: 2023-09-27 18:12:22

我似乎不明白为什么我总是得到以下错误:

Bytes to be written to the stream exceed the Content-Length bytes size specified.

:

writeStream.Write(bytes, 0, bytes.Length);

这是一个Windows窗体项目。如果有人知道这里发生了什么，我肯定欠你一个人情。

    private void Post()
    {

        HttpWebRequest request = null;
        Uri uri = new Uri("xxxxx");
        request = (HttpWebRequest)WebRequest.Create(uri);
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
        XmlDocument doc = new XmlDocument();
        doc.Load("XMLFile1.xml");
        request.ContentLength = doc.InnerXml.Length;
        using (Stream writeStream = request.GetRequestStream())
        {
            UTF8Encoding encoding = new UTF8Encoding();
            byte[] bytes = encoding.GetBytes(doc.InnerXml);
            writeStream.Write(bytes, 0, bytes.Length);
        }
        string result = string.Empty;
        request.ProtocolVersion = System.Net.HttpVersion.Version11;
        request.KeepAlive = false;
        try
        {
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                using (Stream responseStream = response.GetResponseStream())
                {
                    using (System.IO.StreamReader readStream = new System.IO.StreamReader(responseStream, Encoding.UTF8))
                    {
                        result = readStream.ReadToEnd();
                    }
                }
            }
        }
        catch (Exception exp)
        {
            // MessageBox.Show(exp.Message);
        }
    }

错误(HttpWebRequest):写入流的字节超过指定的Content-Length字节大小

有三个可能的选项

  • 修复@rene

    • 回答中描述的ContentLength

  • 不要设置ContentLength, HttpWebRequest正在缓冲数据，并自动设置ContentLength

  • SendChunked属性设置为true，不设置ContentLength。将请求发送块编码到web服务器。(需要HTTP 1.1并且必须被web服务器支持)

代码:

...
request.SendChunked = true;
using (Stream writeStream = request.GetRequestStream())
{ ... }

来自InnerXml的编码字节数组可能更长，因为UTF8编码中的某些字符占用2或3个字节。

修改代码如下:

    using (Stream writeStream = request.GetRequestStream())
    {
        UTF8Encoding encoding = new UTF8Encoding();
        byte[] bytes = encoding.GetBytes(doc.InnerXml);
        request.ContentLength = bytes.Length;
        writeStream.Write(bytes, 0, bytes.Length);
    }

要准确显示正在发生的事情，请在LINQPad中尝试:

var s = "é";
s.Length.Dump("string length");
Encoding.UTF8.GetBytes(s).Length.Dump("array length");

这将输出:

 string length: 1 
 array length:  2

，现在使用不带撇号的e:

var s = "e";
s.Length.Dump("string length");
Encoding.UTF8.GetBytes(s).Length.Dump("array length");

将输出:

string length: 1 
array length:  1

所以请记住:字符串长度和特定编码所需的字节数可能不同。

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