因为工作需要调用WebService接口，查了下资料，发现添加服务引用可以直接调用websevice
参考地址：https://www.cnblogs.com/peterpc/p/4628441.html
如果不添加服务引用又怎么做呢？于是又去查看怎么根据http协议调用webservice并做了个无参接口测试，如下：
但一做有参的接口调用就提示500错误（远程服务器返回错误(500)内部服务器错误），查了半天资料，大多数都说是ContentType = "application/x-www-form-urlencoded; charset=UTF-8"; 改成ContentType = "text/html";或者在<@Page..%>中设置 ValidateRequest="false" 即可（这里无需修改Content-type）。结果还是报一样的错误。最后再https://www.jb51.net/article/120015.htm中发现参数是要拼接一下的 (param = HttpUtility.UrlEncode("param1") +"="+ HttpUtility.UrlEncode(num1) +"&"+ HttpUtility.UrlEncode("param2") +"="+ HttpUtility.UrlEncode(num2);) ,这样传递int、string类型的参数都没问题。业务要求传递的是图片二进制转化的string类型数据，结果还是报500错误。经过调试对比发现图片二进制数据转化成的string类型数据没有根据url形式传递，而是带有特殊符号的，知道问题所在就好办了，把它转化成有效的url传输数据就行,.net也有现成的封装方法：HttpServerUtility.UrlTokenEncode(bmpBytes)，这样500错误也解决了。
测试代码如下：
1 protected void Page_Load(objectsender, EventArgs e) 2 { 3 Bitmap bmp = new Bitmap(System.Drawing.Image.FromFile("C:/Users/TYTD/Desktop/测试样本/ch_DJI_279.jpg")); 4 MemoryStream ms = newMemoryStream(); 5 bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); 6 ms.Flush(); 7 //将二进制数据存到byte数组中 8 byte[] bmpBytes1 =ms.ToArray(); 9 bmp.Dispose(); 10 11 string bmpBytes = HttpUtility.UrlEncode("bmpBytes") + "=" +HttpServerUtility.UrlTokenEncode(bmpBytes1); 12 13 string url = "http://192.168.0.28:9800/WebService1.asmx/Send_Image"; 14 string a =CallServiceByGet1(url, bmpBytes); 15 16 } 17 public static string CallServiceByGet1(string strURL,stringa) 18 { 19 var result = string.Empty; 20 //创建一个HTTP请求 21 byte[] byt =Encoding.UTF8.GetBytes(a); 22 HttpWebRequest request =(HttpWebRequest)WebRequest.Create(strURL); 23 request.Method = "POST"; 24 request.ContentType = "application/x-www-form-urlencoded"; 25 request.ContentLength =byt.Length; 26 27 request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)"; 28 System.IO.Stream outputStream =request.GetRequestStream(); 29 outputStream.Write(byt, 0, byt.Length); 30 outputStream.Close(); 31 32 HttpWebResponse response; 33 Stream responseStream; 34 StreamReader reader; 35 stringsrcString; 36 try 37 { 38 response = (HttpWebResponse)request.GetResponse();//获取http请求的响应对象 39 } 40 catch(WebException ex) 41 { 42 returnex.Message; 43 } 44 responseStream =response.GetResponseStream(); 45 reader = new System.IO.StreamReader(responseStream, Encoding.GetEncoding("UTF-8")); 46 srcString =reader.ReadToEnd(); 47 result = srcString; //返回值赋值 48 reader.Close(); 49 50 returnresult; 51 }