JS代码：

var word = document.getElementById("word").value;

$.ajax({

    type: "POST",

    contentType: "application/x-www-form-urlencoded",

    url: "http://localhost:12805/WebService.asmx/HelloWorld",

    data: 'data=' + word,

    dataType: 'text',

    success: function(result) {

        alert("success: " + result);

    },

    error: function(result, status) {

        alert("error: " + status);

    }

});

C# WebService代码：

[WebService(Namespace = "weburl")]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

[System.ComponentModel.ToolboxItem(false)]

// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.

[System.Web.Script.Services.ScriptService]

public class WebService : System.Web.Services.WebService

{

    [WebMethod]

    public void HelloWorld(string data)

    {

        this.Context.Response.AddHeader("Access-Control-Allow-Origin", "*"); // CORS 跨域訪问

        this.Context.Response.Write(data); // 返回字符串格式

    }

}

WebService 默认 return 返回 XML 格式，可是使用上述方式是以字符串形式返回。