[System.Web.Script.Services.ScriptService]public class TestService : System.Web.Services.WebService{[WebMethod]public string Test(string inputStr){HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");return "Hello :"+inputStr;}}

<!--
  有关如何配置 ASP.NET 应用程序的详细信息，请访问
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->

<configuration>
    <system.web>
      <compilation debug="true" targetFramework="4.0" />
      <customErrors mode="Off"/>
      <webServices>
        <protocols>
          <add name="HttpSoap"/>
          <add name="HttpPost"/>
          <add name="HttpGet"/>
          <add name="Documentation"/>
        </protocols>
      </webServices>
    </system.web>
  <system.webServer>
    <httpProtocol>
      <customHeaders>
        <add name="Access-Control-Allow-Methods" value="OPTIONS,POST,GET"/>
        <add name="Access-Control-Allow-Headers" value="x-requested-with,content-type"/>
        <add name="Access-Control-Allow-Origin" value="*" />
      </customHeaders>
    </httpProtocol>
  </system.webServer>

</configuration>

function doClick1() {

        $.ajax({type: "post",url: "http://xx.com/TestService.asmx/Test",dataType: 'xml',data: { inputStr: 'everyone' },success: function (data) {alert(data); //xml对象},error: function (XMLHttpRequest, textStatus, errorThrown) {console.log(XMLHttpRequest);alert('error:' + errorThrown);}});}