Question

所以这就是代码：

void scrape() 
{ 
    int i = 1;
    ......
    backgroundWorker1.ReportProgress(i);
    i = i+1;
}
void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) 
{
    progressBar1.Value = e.ProgressPercentage;
}
void BackgroundWorker1DoWork(object sender, DoWorkEventArgs e)
{
    scrape();
}
void Button1Click(object sender, EventArgs e)
{
    backgroundWorker1.RunWorkerAsync();
}

问题是，如果我点击botton1没有任何反应，如果我只是在button1上使用scrape（），它就可以正常工作了。为什么后台工作人员不执行刮擦并使进度条工作？

谢谢！

Answer 1

在scrape()方法中，您如何使用变量i？要使它工作i应该通过循环递增，如下所示：

void scrape()
{
    for (int i = 1; i <= 100; i++)
    {
        backgroundWorker1.ReportProgress(i);
    }
}

我可以确认上面的代码对我有用。然后不要忘记连接所需的事件和属性：

backgroundWorker1.WorkerReportsProgress = true; //Report a progress
backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;
backgroundWorker1.DoWork += BackgroundWorker1DoWork; //The scrape

定义：

void BackgroundWorker1DoWork(object sender, DoWorkEventArgs e)
{
    scrape();
}

Answer 2

在程序的Initialization / Constructor中，您需要添加这些行以使其正常工作

BackgroundWorker1.DoWork += new BackgroundWorkerDoWorkEventHandler(BackgroundWorker1DoWork)

同样地，它也会转到代码的其他部分

BackgroundWorker1.ProgressChanged += new ProgressChangedEventHandler (backgroundWorker1_ProgressChanged);
BackgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker1_RunWorkerCompleted);
BackgroundWorker1.WorkerReportsProgress = true;
BackgroundWorker1.WorkerSupportsCancellation = true;

BackgroundWorker不起作用

2 个答案: