使用ajax調用webservice的接口方法

注意：調用的時候，前台js里面的那個參數和后台接口的方法的參數名字和字母大小寫一定要一樣的。

1.前台的代碼如下：

$(function () {

    var categoryNum = "002007";
    var requestData = " { \"categoryNum\": \"" + categoryNum + "\"} ";


    $.ajax({
        url: prexUrl + "SmtpService/HkmhWebService/HkmhCommonService.asmx/getMaxMinYear",
        type: "post",
        contentType: "application/json; charset=utf-8",
        data: requestData,
        dataType: "json",
        async: true,
        success: function (data) {
            var html = "";
            var rtData = data.d;
            var repData = eval("(" + rtData + ")");
            $("#getYear").empty();

            var MaxYearInfo = repData.Year[0]["MaxYear"];   //最大年份
            var MinYearInfo = repData.Year[0]["MinYear"];    //最小年份

            if ((MaxYearInfo - MinYearInfo) == 0) {
             
                //只加一年
                html += "<option value=\"" + MaxYear + "\">" + MaxYear + "年</option>";
            }
            else if ((MaxYearInfo - MinYearInfo) == 1) {
                //只加最大一年和最小一年
                html += "<option value=\"" + MaxYearInfo + "\">" + MaxYearInfo + "年</option>";
                html += "<option value=\"" + MinYearInfo + "\">" + MinYearInfo + "年</option>";
            }
            else {
                var diffTime = parseInt(MaxYearInfo) - parseInt(MinYearInfo);
                for (var i = 0; i <= diffTime; i++) {
                    html += "<option value=\"" + parseInt(parseInt(MaxYearInfo) - i) + "\">" + parseInt(parseInt(MaxYearInfo) - i) + "年</option>";
                }
            }

            $("#getYear").append(html);
        },
        error: function (data, status) {
            $("#getYear").empty();
            $("#getYear").append("網絡連接超時！請檢查網絡...");
        }
    });

});

2.后台接口的asmx代碼如下：

   public class HkmhCommonService : System.Web.Services.WebService
     {
        public string getMaxMinYear(string categoryNum)
        {
            string strSql = "select top 1 max(infodate) MaxInfodate,min(infodate) MinInfodate from view_infomain where CategoryNum like '" + categoryNum + "' and InfoStatusCode = 9 ";
            DataView dv = new Epoint.Common.DBOperate().ExecuteSQL_ToDataView(StrConstring, strSql);
            var Params = "{\"Year\":[{\"MaxYear\":\"0\",\"MinYear\":0}]}";
            if (dv.Count <= 0)
            {
                return Params;
            }

            string MaxYear = dv[0]["MaxInfodate"].ToString().Substring(0, 4);
            string MinYear = dv[0]["MinInfodate"].ToString().Substring(0, 4);
            //Params = "{'MaxYear':'"+MaxYear+"' ,'MinYear':'"+MinYear+"' }";
            Params = "{\"Year\":[{\"MaxYear\":\"" + MaxYear + "\",\"MinYear\":\"" + MinYear + "\"}]}";
            return Params;
        }
      }