Question

我只想在长时间运行服务器调用时创建进度条。当控制器执行长时间运行的作业时，我无法向控制器创建ajax post请求。

我想创建一个额外的操作来获取当前长时间运行任务的实际语句。我尝试在ajax请求中创建轮询，然后我可以从服务器端返回状态并将其显示在客户端进度条中。有任何想法吗？

Answer 1

使用SignalR这是正确而最简单的方法。请在https://www.nuget.org/packages/Microsoft.AspNet.SignalR/2.1.2

下载Microsoft SignalR

在名为hubs的项目路径中的单独文件夹中创建一个hub类，将两个类文件添加到hubs文件夹中

Startup.cs

using Owin;
using Microsoft.Owin;
[assembly: OwinStartup(typeof(SignalRChat.Startup))]
namespace SignalRChat
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // Any connection or hub wire up and configuration should go here
            app.MapSignalR();
        }
    }
}

ProgressHub.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Web;
using Microsoft.AspNet.SignalR;

namespace RealTimeProgressBar
{
    public class ProgressHub : Hub
    {

        public string msg = "Initializing and Preparing...";
        public int count = 1;

        public static void SendMessage(string msg , int count)
        {
            var message = "Process completed for " + msg;
            var hubContext = GlobalHost.ConnectionManager.GetHubContext<ProgressHub>();
            hubContext.Clients.All.sendMessage(string.Format(message), count);
        }

        public void GetCountAndMessage()
        {
            Clients.Caller.sendMessage(string.Format(msg), count);
        }
    }
}

在控制器中，

// assemblies
using Microsoft.AspNet.SignalR;
using RealTimeProgressBar;   


//call this method inside your working action
ProgressHub.SendMessage("initializing and preparing",  2);

在视图中，

<!--The jQuery library is required and is referenced by default in _Layout.cshtml. -->
<!--Reference the SignalR library. -->
<script src="~/Scripts/jquery.signalR-2.1.2.min.js"></script>
<!--Reference the autogenerated SignalR hub script. -->
<script src="~/signalr/hubs"></script>
<!--SignalR script to update the chat page and send messages.--> 
<script type="text/javascript">
  $(document).ready(function () {

    $("#progressBar").kendoProgressBar({
        min: 0,
        max: 100,
        type: "percent",
    });
});

function StartInvoicing()
{
    var progressNotifier = $.connection.progressHub;

    // client-side sendMessage function that will be called from the server-side
    progressNotifier.client.sendMessage = function (message, count) {
        // update progress
        UpdateProgress(message, count);
        //alert(message);
    };

    // establish the connection to the server and start server-side operation
    $.connection.hub.start().done(function () {
        // call the method CallLongOperation defined in the Hub
        progressNotifier.server.getCountAndMessage();
    });
}

// Update the progress bar 
function UpdateProgress(message, count) {
    var result = $("#result");
    result.html(message);
    $("#progressBar").data("kendoProgressBar").value(count);
}
</script>

有关详细信息，请参阅google

帮助下的一些现有文章

Answer 2

我有一个长期服务，我在下面给出了一个基本的想法。根据您的要求使用它。

我制作了进度参数ProgressArgs
在长时间运行的服务LongRunningProcess（）中，定期更新进度值并以JSON格式保存在数据库中
创建了一个Action方法getProgress()，它将通过ajax返回JSON字符串进度。
创建了一个函数Javascript getProgress()函数，该函数一旦启动就会定期调用服务器，直到进程完成为止。

我给出了一个粗略的例子来实现它。希望它可以帮助你。

进度参数结构的类

public class ProgressArgs
{
    public int Completed { get; set; }
    public int Total { get; set; }
    public int Percentage { get; set; }
    public string Status { get; set; }
}

在过程中，我一直在更新数据库中的统计数据

    public void LongRunningProcess()
    {

        ProgressArgs result = new ProgressArgs();
        result.Completed = 0;
        result.Total = userList.Count;
        foreach (var item in itemList)
        {
           //Do Some processing which u want to do

            result.Total++;
            result.Percentage = (result.Completed * 100) / result.Total;
            result.Status = "Processing";
            string strToSave = Newtonsoft.Json.JsonConvert.SerializeObject(result);
            //update the strToSave to the database somewhere.
        }

        //after completing of processing
        result.Total++;
        result.Percentage = (result.Completed * 100) / result.Total;
        result.Status = "Completed";
        string strToSave = Newtonsoft.Json.JsonConvert.SerializeObject(result);
        //update the strToSave to the database somewhere.

    }

通过ajax获取进度的C＃动作

    public string getProgress()
    {    
        string strJSON = config.GetValue("progress");  //Get stats from the database which is saved in json
        return strJSON;
    }

Javascript代码

//Ajax Get Progress function
    function getProgress() {
        var dataToSend = '';
        $.ajax({
            url: '@Url.Action("getProgress")', //Link to the action method
            type: 'POST',
            contentType: 'application/json; charset=utf-8',
            data: dataToSend,
            success: function (response) {
                console.log(response);
                if (response != null) {
                    data = JSON.parse(response);
                    console.log(data);
                    //update the progressbar
                    progressbar.progressbar("value", data.Percentage);
                    //When the jobalert status is completed clear the interval
                    if (data.Status == 0) {
                        setTimeout(getProgress, 800); //TImout function to call the respective function at that time
                    }
                    serviceCompleted(data); function to call after completing service
                }
            },
            error: function (xhr) {
                alert('Error: There was some error while posting question. Please try again later.');
            }
        });
    }

ASP.Net MVC中长时间运行的服务器调用的进度条

2 个答案: