c# - 在 c# 中使用 HttpWebRequest 发送 base64 字符串将 "+"转换为空白问题

Question

我将图像转换为 base64 字符串以通过 C# 中的 HttpWebRequest 上传。在服务器端，当我收到 base64 字符串时，“+”符号已转换为空格“”。将此 base64 字符串转换为字节数组时出错。我不想在服务器端(在 Web 服务中)进行任何更改。我想在客户端解决这个问题。我的客户端代码如下。

/////////////////

WSManagerResult wsResult = new WSManagerResult();

        try
        {
            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(serviceURL);
            req.Method = "POST";
            req.ProtocolVersion = HttpVersion.Version11;
            req.ContentType = "application/x-www-form-urlencoded";
            //  req.ContentType = "application/x-www-form-urlencoded; charset=utf-8";
            // req.CookieContainer = new CookieContainer();


            string content = string.Empty;
            foreach (KeyValuePair<string, string> entry in paramDic)
            {

//entry.Value 是根据图像评分的 base 64 字符串基因

             content = content + entry.Key + "=" + entry.Value + "&&";
            }
            content = content.TrimEnd('&'); // input parameter if u have more that one //a=b&dd=aa               
            req.ContentLength = content.Length;
            // req = URLEncode(content);
            Stream wri = req.GetRequestStream();


            byte[] array = Encoding.ASCII.GetBytes(content);
            if (array.Length > 0)
                wri.Write(array, 0, array.Length);
            wri.Flush();
            wri.Close();
            WebResponse rsp = (HttpWebResponse)req.GetResponse();


            byte[] b = null;
            using (Stream stream = rsp.GetResponseStream())
            using (MemoryStream ms = new MemoryStream())
            {
                int count = 0;
                do
                {
                    byte[] buf = new byte[1024];
                    count = stream.Read(buf, 0, 1024);
                    ms.Write(buf, 0, count);
                } while (stream.CanRead && count > 0);
                b = ms.ToArray();
            }
            wsResult.result = Encoding.ASCII.GetString(b);
        }
        catch (Exception e)
        {
            clsException.ExceptionInstance.HandleException(e);
            wsResult.error = e.Message;
        }


        return wsResult;

上述 base64 字符串中的所有“+”符号都被转换为“”空格。这会导致上述问题。

请帮我解决这个问题。

问候

沙哈立德

Answer 1

非常感谢 Rob。它通过在客户端将“+”替换为十六进制“%2B”以通过 wire 发布数据来解决我的问题。如下面的 c# 所示。

/*Using standard Base64 in URL requires encoding of '+', '/' and '=' characters into special percent-encoded hexadecimal sequences ('+' = '%2B', '/' = '%2F' and '=' = '%3D')*/ 

String stbase64datatopost =stbase64datatopost.Replace("+",@"%2B"); 
stbase64datatopost = stbase64datatopost .Replace("/",@"%2F");      
stbase64datatopost=stbase64datatopost.Replace("=",@"%3D");