转自 https://www.cnblogs.com/Brambling/p/7266482.html
之前调用 WebService 都是直接添加服务引用，然后调用 WebService 方法的，最近发现还可以使用 Http 请求调用 WebService。这里还想说一句，还是 web api 的调用简单。
WebService 服务端代码：
public class WebServiceDemo : System.Web.Services.WebService
{ [WebMethod]
public string HelloWorld()
{
return "Hello World";
} [WebMethod]
public string Sum(string param1, string param2)
{
int num1 = Convert.ToInt32(param1);
int num2 = Convert.ToInt32(param2); int sum = num1 + num2; return sum.ToString();
}
}
很简单的代码，只是用于演示。
客户端调用代码：
class Program
{
static void Main(string[] args)
{
Program program = new Program();
string url = "http://localhost:12544/WebServiceDemo.asmx";
string method = "Sum";
string num1 = "1";
string num2 = "2"; string result = program.HttpPostWebService(url, method, num1, num2); Console.WriteLine(result);
Console.ReadKey();
} public string HttpPostWebService(string url,string method,string num1,string num2)
{
string result = string.Empty;
string param = string.Empty;
byte[] bytes = null; Stream writer = null;
HttpWebRequest request = null;
HttpWebResponse response = null; param = HttpUtility.UrlEncode("param1") + "=" + HttpUtility.UrlEncode(num1) + "&" + HttpUtility.UrlEncode("param2") + "=" + HttpUtility.UrlEncode(num2);
bytes = Encoding.UTF8.GetBytes(param); request = (HttpWebRequest)WebRequest.Create(url + "/" + method);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = bytes.Length; try
{
writer = request.GetRequestStream(); //获取用于写入请求数据的Stream对象
}
catch (Exception ex)
{
return "";
} writer.Write(bytes, 0, bytes.Length); //把参数数据写入请求数据流
writer.Close(); try
{
response = (HttpWebResponse)request.GetResponse(); //获得响应
}
catch (WebException ex)
{
return "";
} #region 这种方式读取到的是一个返回的结果字符串
Stream stream = response.GetResponseStream(); //获取响应流
XmlTextReader Reader = new XmlTextReader(stream);
Reader.MoveToContent();
result = Reader.ReadInnerXml();
#endregion #region 这种方式读取到的是一个Xml格式的字符串
//StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
//result = reader.ReadToEnd();
#endregion response.Dispose();
response.Close(); //reader.Close();
//reader.Dispose(); Reader.Dispose();
Reader.Close(); stream.Dispose();
stream.Close(); return result;
}
}
第一种读取方式的返回结果：
第二种读取方式的返回结果：
PS：如果遇到调用时报错，可以尝试在服务端（即WebService）的 web.config 配置中添加如下配置节点。
<system.web>
<webServices>
<protocols>
<add name="HttpPost" />
</protocols>
</webServices>
</system.web>
参考：
