如何在asp.net中调用WebMethod并显示警报消息

Question

我正在尝试使用“ WebMethod”发出警报消息，其中我的情况如下

1.我试图限制用户在“星期一”申请休假，因为他/她已经在上一个星期五休了假。 2.我正在从员工保留“详细信息”的数据库中收集详细信息，并尝试在WebMethod中进行编码

我的CS页面代码：

   [System.Web.Services.WebMethod]
public  string GetCurrentTime()
{
    SqlConnection con = new SqlConnection(conString);
    con.Open();
    SqlCommand cn = new SqlCommand();
    DateTime date3 = System.DateTime.Now;
    DateTime date4 = System.DateTime.Now;
    DateTime date1 = System.DateTime.Now.AddDays(-6); ;
    DateTime date2 = System.DateTime.Now.AddDays(-6);
    DateTime.TryParse(txtFromDate.Text, out date1);
    DateTime.TryParse(txtToDate.Text, out date2);

   // string val;
   // var EmpID = "SS212";
    SqlDataAdapter da = new SqlDataAdapter(scmd);
        DataTable dt=new DataTable();
        da.Fill(dt);
        sdr = scmd.ExecuteReader();
    if (date1.DayOfWeek == DayOfWeek.Monday && date2.DayOfWeek == DayOfWeek.Monday)
    {
        string Leave = "Select EmpID ,LeaveType,LeaveFromDate,LeaveToDate,LeaveStatus from LeaveApplication Where LeaveFromDate  = '" + date1 + "' and LeaveToDate  = '" + date2 + "'";
        scmd = new SqlCommand(Leave, scon);



    }
    for(int i = 0; i < dt.Rows.Count; i++)
    {

        String value ;
        if ((dt.Rows[i]["LeaveStatus"].ToString() == "Accepted") || (dt.Rows[i]["LeaveStatus"].ToString() == "Pending")) 

    {
      value="";

    }
        else 
    {

        value = "";
    }

    }


    return "";       
}

我的aspx：

        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
    function ShowCurrentDate() {

        $.ajax({
            type: "POST",
            url: "LMSEmployee.aspx/GetCurrentTime",
            data: params,
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: OnSuccess,
            failure: function (response) {
                alert("Please");
            }
        });
    }
    function OnSuccess(response) {
        alert("Please");

    }
    </script>

Answer 1

Webmethod仅适用于静态函数，因此请尝试

public static  string GetCurrentTime()

代替

public  string GetCurrentTime() 

请注意，如果您这样做，则通常在事件驱动功能（IE服务器端单击事件）中附带的事件驱动功能将无法工作

迈克（Mike）有一个很棒的帖子

https://www.mikesdotnetting.com/article/104/many-ways-to-communicate-with-your-database-using-jquery-ajax-and-asp-net

Answer 2

示例//只是汽车课

 public class Cars
    {
        public string carName;
        public string carRating;
        public string carYear;
    }


//Your Webmethod*
[WebMethod]
public List<Cars> getListOfCars(List<string> aData)
{
    SqlDataReader dr;
    List<Cars> carList = new List<Cars>();

    using (SqlConnection con = new SqlConnection(conn))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "spGetCars";
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Connection = con;
            cmd.Parameters.AddWithValue("@makeYear", aData[0]);
            con.Open();
            dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            if (dr.HasRows)
            {
                while (dr.Read())
                {
                    string carname = dr["carName"].ToString();
                    string carrating = dr["carRating"].ToString();
                    string makingyear = dr["carYear"].ToString();

                    carList.Add(new Cars
                                    {
                                        carName = carname,
                                        carRating = carrating,
                                        carYear = makingyear
                                    });
                }
            }
        }
    }
    return carList;
}
//*

//Your Client Side code
    $("#myButton").on("click", function (e) {
        e.preventDefault();
        var aData= [];
        aData[0] = $("#ddlSelectYear").val(); 
        $("#contentHolder").empty();
        var jsonData = JSON.stringify({ aData:aData});
        $.ajax({
            type: "POST",
            //getListOfCars is my webmethod   
            url: "WebService.asmx/getListOfCars", 
            data: jsonData,
            contentType: "application/json; charset=utf-8",
            dataType: "json", // dataType is json format
            success: OnSuccess,
            error: OnErrorCall
        });

        function OnSuccess(response) {
          console.log(response.d)
        }
        function OnErrorCall(response) { console.log(error); }
        });