如何使用BackgroundWorker
本文关键字：BackgroundWorker 何使用 | 更新日期: 2023-09-27 18:00:18
我知道它有3个方法。在我的程序中，我有一个发送消息的方法。它经常很晚，程序有时根本不发送消息来响应按钮按下。有时，它比我预期的晚了5秒，程序冻结了。我想使用BackgroundWorker按预期发送消息，并允许程序始终正常运行。我在按钮处理程序中有发送消息的代码。现在我把这个等价的代码放在哪里？我希望所有这些仍然可以通过按下按钮来处理。
这是合适的处理程序吗？
backgroundWorker1.RunWorkerAsync();
和：
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) {}
我要把我的代码放在按钮处理程序中吗？在此之前：
carga.progressBar1.Minimum = 0;
carga.progressBar1.Maximum = 100;
Carga是ProgressBar所在的另一种形式。在这种情况下，我如何使用BackgroundWorker？
您只能从ProgressChanged或RunWorkerCompleted事件处理程序更新进度条，因为它们与UI线程同步。
基本思想是Thread.Sleep只是模拟了这里的一些工作。将其替换为真实的路由呼叫。
public Form1()
{
InitializeComponent();
backgroundWorker1.DoWork += backgroundWorker1_DoWork;
backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;
backgroundWorker1.WorkerReportsProgress = true;
}
private void button1_Click(object sender, EventArgs e)
{
backgroundWorker1.RunWorkerAsync();
}
private void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
for (int i = 0; i < 100; i++)
{
Thread.Sleep(1000);
backgroundWorker1.ReportProgress(i);
}
}
private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}
我知道这有点过时，但如果另一个初学者正在经历这一过程，我将分享一些涵盖更多基本操作的代码，这里是另一个例子，还包括取消进程并向用户报告进程状态的选项。我将在上面的解决方案中添加Alex Aza给出的代码
public Form1()
{
InitializeComponent();
backgroundWorker1.DoWork += backgroundWorker1_DoWork;
backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;
backgroundWorker1.RunWorkerCompleted += backgroundWorker1_RunWorkerCompleted; //Tell the user how the process went
backgroundWorker1.WorkerReportsProgress = true;
backgroundWorker1.WorkerSupportsCancellation = true; //Allow for the process to be cancelled
}
//Start Process
private void button1_Click(object sender, EventArgs e)
{
backgroundWorker1.RunWorkerAsync();
}
//Cancel Process
private void button2_Click(object sender, EventArgs e)
{
//Check if background worker is doing anything and send a cancellation if it is
if (backgroundWorker1.IsBusy)
{
backgroundWorker1.CancelAsync();
}
}
private void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
for (int i = 0; i < 100; i++)
{
Thread.Sleep(1000);
backgroundWorker1.ReportProgress(i);
//Check if there is a request to cancel the process
if (backgroundWorker1.CancellationPending)
{
e.Cancel = true;
backgroundWorker1.ReportProgress(0);
return;
}
}
//If the process exits the loop, ensure that progress is set to 100%
//Remember in the loop we set i < 100 so in theory the process will complete at 99%
backgroundWorker1.ReportProgress(100);
}
private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}
private void backgroundWorker1_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e)
{
if (e.Cancelled)
{
lblStatus.Text = "Process was cancelled";
}
else if (e.Error != null)
{
lblStatus.Text = "There was an error running the process. The thread aborted";
}
else
{
lblStatus.Text = "Process was completed";
}
}