Question

我有一个简单的应用程序，它触发了一系列数据密集型任务。我对WinForms不是很有经验，我想知道在不锁定界面的情况下最好的方法。可以重复使用backgroundWorker，还是有其他方法可以做到这一点？

由于

Answer 1

backgroundWorker 可以使用。

它的好处 - 它允许您更新进度条并与UI控件交互。（WorkerReportsProgress）

它还有取消机制。（WorkerSupportsCancellation）

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Answer 2

BackgroundWorker是一个包含通知同步的线程。例如，如果您想在扫描完成时更新UI，则常规Thread无法访问UI对象（只有UI线程可以执行此操作）;因此，BackgroundWorker提供了一个Completed事件处理程序，该处理程序在操作完成时在UI线程上运行。

有关详细信息，请参阅：Walkthrough: Multithreading with the BackgroundWorker Component （MSDN）

和一个简单的示例代码：

var worker = new System.ComponentModel.BackgroundWorker();
worker.DoWork += (sender,e) => Thread.Sleep(60000);
worker.RunWorkerCompleted += (sender,e) => MessageBox.Show("Hello there!");
worker.RunWorkerAsync();

Answer 3

后台工作人员将是一个很好的选择

有关详情，请点击此处 http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

Answer 4

您可以将BackgroundWorker用于此类要求。以下是updates a label status based on percentage task [long running] completion的示例。此外，还有一个示例业务类，它设置了一些值，并通过ProgressChanged处理程序将值设置回UI。 DoWork是您编写长期运行任务逻辑的地方。复制 - 在Winforms应用程序＆amp;添加标签和后台工作组件后粘贴下面的代码试一试。您可以跨各种处理程序[RunWorkerCompleted, ProgressChanged, DoWork]进行调试，并查看InitWorker方法。请注意cancellation feature。

using System.ComponentModel;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form3 : Form
    {
        private BackgroundWorker _worker;
        BusinessClass _biz = new BusinessClass();
        public Form3()
        {
            InitializeComponent();
            InitWorker();
        }

        private void InitWorker()
        {
            if (_worker != null)
            {
                _worker.Dispose();
            }

            _worker = new BackgroundWorker
            {
                WorkerReportsProgress = true,
                WorkerSupportsCancellation = true
            };
            _worker.DoWork += DoWork;
            _worker.RunWorkerCompleted += RunWorkerCompleted;
            _worker.ProgressChanged += ProgressChanged;
            _worker.RunWorkerAsync();
        }


        void DoWork(object sender, DoWorkEventArgs e)
        {
            int highestPercentageReached = 0;
            if (_worker.CancellationPending)
            {
                e.Cancel = true;
            }
            else
            {
                double i = 0.0d;
                int junk = 0;
                for (i = 0; i <= 199990000; i++)
                {
                    int result = _biz.MyFunction(junk);
                    junk++;

                    // Report progress as a percentage of the total task.
                    var percentComplete = (int)(i / 199990000 * 100);
                    if (percentComplete > highestPercentageReached)
                    {
                        highestPercentageReached = percentComplete;
                        // note I can pass the business class result also and display the same in the LABEL  
                        _worker.ReportProgress(percentComplete, result);
                        _worker.CancelAsync();
                    }
                }

            }
        }

        void RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (e.Cancelled)
            {
                // Display some message to the user that task has been
                // cancelled
            }
            else if (e.Error != null)
            {
                // Do something with the error
            }
        }

        void ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            label1.Text =  string.Format("Result {0}: Percent {1}",e.UserState, e.ProgressPercentage);
        }
    }

    public class BusinessClass
    {
        public int MyFunction(int input)
        {
            return input+10;
        }
    }
}

WinForm多线程。是否使用backgroundWorker？

4 个答案: