Question

我有一个加载文件的方法。有时需要花费很多时间，所以我想向用户显示一个progressBar窗口，用它可以最小化整个应用程序或取消进度。

我已经阅读了一些关于BackgroundWorkers和ProgressBars的教程，但是当ProgressBar位于其他Form时，这些教程都没有涵盖这个场景。我不知道我应该何时打开新表单以及如何访问那里的进度条。

到目前为止，我已经尝试过：

的MainForm：

private void addFolderToolStripMenuItem_Click(object sender, EventArgs e)
{
    ctlFolderSelectDialog dlg = new ctlFolderSelectDialog();
    if (dlg.ShowDialog() == DialogResult.OK)
    {
        BackgroundWorker.RunWorkerAsync(dlg); // to pass some variables from ctlFolderSelectDialog
    }
}

private void BackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
    Form_Dialogs.ProgressDialog progressDialog = new Form_Dialogs.ProgressDialog();
    progressDialog.ShowDialog(); // open the progress dialog window

    myClass.loadFiles((ctlFolderSelectDialog)e.Argument); // THE WORK

    progressDialog.Close(); // close the progress window - in here?
}

MyClass的：

public void loadFiles(ctlFolderSelectDialog dlg)
{
    ...
    files.Count() // somehow report this preliminary number of files to ProgressBar window - to set ProgressBar1.Maximum value
    ...
    foreach (file in files)
    {
        loadFile();
        ... // here I should somehow udpate the progressBar on the other window - performStep()
    }
}

ProgressDialog：

private void ProgressDialog_Load(object sender, EventArgs e)
{
    progressBar1.Value = 0;
    progressBar1.Maximum = 100; // how to get this value from myClass function? Pass in ProgressDialog contructor?
    progressBar1.Step = 1;
}

public void UpdateProgress(int progress)
{
    progressBar1.PerformStep();
}

Answer 1

BackgroundWorker通过ProgressChanged事件支持进度更新。

在loadFiles()方法中，您需要在foreach循环调用backgroundWorker.ReportProgress(percentage)内计算％的进度。这将引发ProgressChanged事件，您可以在事件参数e.ProgressPercentage中获取该事件。 [您需要引用BackgroundWorker方法中的loadFiles()

在ProgressDialog表单中，您需要注册此活动。您可以在构造函数中传递BackgroundWorker，例如

public void ProgressDialog(BackgroundWorker worker)
{
   worker.ProgressChanged += ProgressDialog_ProgressChanged;
}

private void ProgressDialog_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
   UpdateProgressBar(e.ProgressPercentage);
}

并以主要形式：

private void addFolderToolStripMenuItem_Click(object sender, EventArgs e)
{
    ctlFolderSelectDialog dlg = new ctlFolderSelectDialog();
    if (dlg.ShowDialog() == DialogResult.OK)
    {
        BackgroundWorker.RunWorkerAsync(dlg); // to pass some variables fromctlFolderSelectDialog
        Form_Dialogs.ProgressDialog progressDialog = 
           new Form_Dialogs.ProgressDialog(BackgroundWorker); // Pass the BackgroundWorker instance
        progressDialog.ShowDialog(); // open the progress dialog window
        // No need to explicitly close it. A dialog form is destroyed when closed by the user.
    }
}

private void BackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
    myClass.loadFiles((ctlFolderSelectDialog)e.Argument); // THE WORK
}

如何使用BackgroundWorker和自定义进度对话框（带有ProgressBar的表单）？

1 个答案: