.net - 如何使用 HttpWebRequest 调用接受 byte[] 参数的 Web 服务操作？

Question

我正在尝试从 C# 调用 [webmethod]。我可以调用接受“字符串”参数的简单 web 方法。但是我有一个 webmethod 接受一个 'byte[]' 参数。当我尝试调用它时，我遇到了“500 内部服务器错误”。这是我正在做的一些例子。

可以说我的方法是这样的

[WebMethod]
public string TestMethod(string a)
{
    return a;
}

我在 C# 中使用 HttpRequest 这样称呼它

            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Credentials = CredentialCache.DefaultCredentials;
            req.Method = "POST";
            // Set the content type of the data being posted.
            req.ContentType = "application/x-www-form-urlencoded";

            string inputData = "sample webservice";
            string postData = "a=" + inputData;
            ASCIIEncoding encoding = new ASCIIEncoding();
            byte[] byte1 = encoding.GetBytes(postData);

            using (HttpWebResponse res = (HttpWebResponse)req.GetResponse())
            {
                StreamReader sr = new StreamReader(res.GetResponseStream());
                string txtOutput = sr.ReadToEnd();
                Console.WriteLine(sr.ReadToEnd());
            }

这工作得很好。现在我有另一个像这样定义的 webmethod

[WebMethod]
public string UploadFile(byte[] data)

我试着这样称呼它

            ASCIIEncoding encoding = new ASCIIEncoding();
            string postData = "data=abc";
            byte[] sendBytes = encoding.GetBytes(postData);
            req.ContentLength = sendBytes.Length;
            Stream newStream = req.GetRequestStream();
            newStream.Write(sendBytes, 0, sendBytes.Length);

但这给了我一个 500 内部错误:(

Answer 1

有可能，我自己做过

首先是 Header 设置，如果您的 webservice 可以通过 web 执行并发送参数，则可以获得此设置。我使用 Chrome 的开发人员工具。简单的方法是查看网络服务的描述(即 http://myweb.com/WS/MyWS.asmx?op=Validation)

WebRequest request = WebRequest.Create(http://myweb.com/WS/MyWS.asmx?op=Validation);
request.Method = "POST";
((HttpWebRequest)request).UserAgent = ".NET Framework Example Client";
request.ContentType = "text/xml; charset=utf-8";
((HttpWebRequest)request).Referer = "http://myweb.com/WS/MyWS.asmx?op=Validation";
((HttpWebRequest)request).Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
((HttpWebRequest)request).Host= "myweb.com";
 request.Headers.Add("SOAPAction","http://myweb.com/WS/Validation");

然后是请求部分

string message = "a=2";
string envelope = "<?xml version=\"1.0\" encoding=\"utf-8\"?><soap:Envelope    xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">"+
        "<soap:Body><Validation xmlns=\"http://myweb.com/WS\"><data>@Data</data></Validation></soap:Body></soap:Envelope>";
string SOAPmessage = envelope.Replace("@Data",   System.Web.HttpUtility.HtmlEncode(message));
// The message must be converted to bytes, so it can be sent by the request
byte[] data = Encoding.UTF8.GetBytes(SOAPmessage);
request.ContentLength = data.Length;
request.Timeout = 20000;
Stream dataStream = request.GetRequestStream();
dataStream.Write(data, 0, data.Length);
dataStream.Close();
WebResponse response = request.GetResponse();
Stream inputStream = response.GetResponseStream(); 

现在您可以从响应中获取传入流

请记住根据来自 Web 服务的页面详细信息(即 http://myweb.com/WS/MyWS.asmx?op=Validation)给出的描述调整要发送的 SOAP 信封和参数。