尝试使用 javascript 捕获页面方法

Question

Javascript 将调用服务器中的 UploadData 函数，如果无法连接到该函数，它将保存到 LocalStorage。

如何在客户端捕获 pagemethod 中的错误？我尝试了以下但未触发捕获。

 try{
      PageMethods.UploadData(val, onlineSuccess, onlineFailed);
 }catch(e)
 {alert("saved in local");}

服务器端：

 [System.Web.Services.WebMethod]
    public static string UploadData(string text)
    {
        if (text == null || text.Length == 0)
            return String.Empty;

            using (SqlConnection cnn = new SqlConnection(ConfigurationManager.ConnectionStrings["scanner"].ConnectionString))
            {
                using (SqlCommand cmd = new SqlCommand())
                {
                    string[] data = text.Split('|');

                    cmd.CommandText ="COMMAND HERE"
                    cmd.Connection = cnn;

                    cmd.Parameters.Clear();
                    .................
                    cnn.Open();
                    try
                    {
                        cmd.ExecuteNonQuery();
                        return data[0].ToString()+" saved";
                    }
                    catch (Exception ex)
                    {
                        return "error : "+ex.Message;
                    }
                }
            }
    }

客户端调用服务端的UploadData函数：

function onlineCall(val) {
    //I want to use try-catch here so when it fails to connect to 
    //the server will save in the local storage

    PageMethods.UploadData(val, onlineSuccess, onlineFailed);
}

function onlineSuccess(res, destCtrl) {
    document.getElementById("scanned_item").innerHTML =res;
}

function onlineFailed(res, destCtrl) {
    alert(res);
}

Answer 1

您只需要使用 ajax 调用此方法并将响应写入本地存储

 $.ajax({
    url: '/Yourcontroller/UploadData',
    type: 'GET',
    data:{text:"text to pass"},
    success: function (response) {

        //do something with response.result
    },
    error: function (response) {
       //write to localstorage response.result
    }
});

像这样装饰控制器

         [HttpGet]

public JsonResult UploadData(string text)
{
    if (text == null || text.Length == 0)
        return String.Empty;

        using (SqlConnection cnn = new SqlConnection(ConfigurationManager.ConnectionStrings["scanner"].ConnectionString))
        {
            using (SqlCommand cmd = new SqlCommand())
            {
                string[] data = text.Split('|');

                cmd.CommandText ="COMMAND HERE"
                cmd.Connection = cnn;

                cmd.Parameters.Clear();
                .................
                cnn.Open();
                try
                {
                    cmd.ExecuteNonQuery();
                //    return data[0].ToString()+" saved";


             return new JsonResult() { result= data[0].ToString()+" saved", JsonRequestBehavior = JsonRequestBehavior.AllowGet };  
                }
                catch (Exception ex)
                {
                 return new JsonResult() { result= ex.ToString()+" saved", JsonRequestBehavior = JsonRequestBehavior.AllowGet };  
                }
            }
        }
}

尝试使用 javascript 捕获页面方法

try catch the pagemethod using javascript

javascript

asp.net

pagemethods