我想了解如何使用 BackgroundWorker。
我试图将它分解为一个控制台 C# 项目，实际上它是一个 Windows 窗体应用程序，其中一个按钮触发三个后台任务的执行。当按钮被按下时，它应该被禁用以防止进一步的按钮事件。当所有三个任务都完成后，该按钮应该再次启用。也应该在主线程中测试这三个任务是否成功。为了防止将这一切混合到 Forms 应用程序中，我现在正在尝试了解基础知识并将其移至 Forms 应用程序。
(从评论设置你可能猜到我理解的问题在哪里)
考虑这个(仍然错误的)代码:
using System;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading;
namespace BGWorkerConsoleApp
{
class Program
{
// #region BackgroundWorker
//
private System.ComponentModel.BackgroundWorker worker = new System.ComponentModel.BackgroundWorker();
//
// #endregion
static void Main(string[] args)
{
// BackgroundWorker worker = new System.ComponentModel.BackgroundWorker();
worker.RunWorkerCompleted += TestComplete;
worker.DoWork += TestConnection1;
// worker.DoWork += TestConnection2;
// worker.DoWork += TestConnection3;
DoWorkEventArgs e = new DoWorkEventArgs(); // ???
worker.RunWorkerAsync(e); // ???
}
private void TestConnection1(object sender, DoWorkEventArgs e)
{
bool success = false;
Thread.Sleep(14000); // stands for some time consuming Task
success = true;
e.Result = success;
}
private void TestConnection2(object sender, DoWorkEventArgs e)
{
bool success = false;
Thread.Sleep(10000); // stands for some time consuming Task
success = true;
e.Result = success;
}
private void TestConnection3(object sender, DoWorkEventArgs e)
{
bool success = false;
Thread.Sleep(5000); // stands for some time consuming Task
success = true;
e.Result = success;
}
private void TestComplete(object sender, RunWorkerCompletedEventArgs e)
{
Console.WriteLine("complete");
}
}
}
我的问题:
我可以向 BackgroundWorker 添加多个任务吗？可能不是，因为只有一个 RunWorkerAsync。假设每项任务都需要一个工作人员，我将如何等待所有三个任务完成？
好的，让我将其更改为 Forms 应用程序，因为压力并不在于在控制台应用程序中运行 BackGroundworker，而是我想了解如何为多个 BackGroundWorker 设计应用程序并等待它们完成(包括参数和结果的传递和返回。
这是表单应用程序中的相同代码:
using System;
using System.Windows.Forms;
using System.ComponentModel;
using System.Threading;
namespace BackGroundWorkerForm
{
partial class Form1
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
private Button button;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.components = new System.ComponentModel.Container();
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.Text = "Form1";
button = new System.Windows.Forms.Button();
button.Location = new System.Drawing.Point(100, 10);
button.Name = "button";
button.Size = new System.Drawing.Size(100, 20);
button.TabIndex = 5;
button.Text = "TestConnection";
button.Click += new System.EventHandler(this.RunTest);
button.Visible = true;
Controls.Add(button);
}
#endregion
private void RunTest(object o, EventArgs e)
{
BackgroundWorker worker = new System.ComponentModel.BackgroundWorker();
worker.RunWorkerCompleted += TestComplete;
worker.DoWork += TestConnection1;
// worker.DoWork += TestConnection2;
// worker.DoWork += TestConnection3;
worker.RunWorkerAsync();
}
private void TestConnection1(object sender, DoWorkEventArgs e)
{
bool success = false;
Thread.Sleep(10000); // stands for some time consuming Task
success = true;
e.Result = success;
}
private void TestConnection2(object sender, DoWorkEventArgs e)
{
bool success = false;
Thread.Sleep(10000); // stands for some time consuming Task
success = true;
e.Result = success;
}
private void TestConnection3(object sender, DoWorkEventArgs e)
{
bool success = false;
Thread.Sleep(10000); // stands for some time consuming Task
success = true;
e.Result = success;
}
private void TestComplete(object sender, RunWorkerCompletedEventArgs e)
{
button.Text= "complete";
}
}
}
最佳答案
这是一个使用 Tasks 而不是后台 worker 的例子。 每个 Task 都是异步启动的，然后等待所有任务是否成功完成，然后再处理结果。
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace BGWorkerConsoleApp
{
class Program
{
static Stopwatch sw = new Stopwatch();
static void Main(string[] args)
{
// parse your args
int[] parsedargs = { 1400, 1000, 500 };
int count = 0; // to provide task count
List<Task> tasks = new List<Task>();
sw.Start(); //stopwatch for some to verify the time
foreach (int i in parsedargs)
{
// start a task for each
tasks.Add(Task.Factory.StartNew<bool>(
() => { return myTask(i, String.Format("Task{0} done. ", ++count)); } ) );
}
// wait for all the tasks to complete
Task.WaitAll(tasks.ToArray());
// check the response of each
bool faulted = false;
foreach (Task<bool> t in tasks)
{
if (t.Result == false)
{
faulted = true;
break; //there was a problem so quit looking
}
}
//output some text
if (faulted)
{
Console.WriteLine("There was a problem.");
}
else
Console.WriteLine("complete");
// pause so we can see our output in the debugger
Console.ReadKey();
}
static bool myTask(int time, string msg)
{
Thread.Sleep(time);
if (time == 1000)
return false;
Console.WriteLine(msg + printStopWatchTime());
return true;
}
static string printStopWatchTime()
{
TimeSpan ts = sw.Elapsed;
string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
ts.Hours, ts.Minutes, ts.Seconds,
ts.Milliseconds / 10);
return string.Format("RunTime {0}", elapsedTime);
}
}
}
关于c# - 了解 BackgroundWorker，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22458498/