修复拖放冻结资源管理器

Question

我有一个应用程序，它允许将数据拖放到其中，然后再对其执行可能很长的操作。这工作正常，但是，当我的应用程序正在处理时，资源管理器窗口会冻结。有没有什么办法可以“释放”它，只要我复制了文件列表？

我目前的代码是：

    private void MainForm_DragDrop(object sender, DragEventArgs e)
    {
        ClearTempFiles(); //Clear all files before populating
        string[] files = (string[])e.Data.GetData(DataFormats.FileDrop); //Get the filepaths for the dragdrop data
        List<string> toParse = new List<string>();
        foreach (string file in files) 
        {
            FileAttributes attr = File.GetAttributes(file);
            if (attr.HasFlag(FileAttributes.Directory)) //If a folder has been included, add all files from within
            {
                toParse.AddRange(DirSearch(file));
            }
            else
            {
                toParse.Add(file); //Add files
            }
        }
        CurrentJobData = new JobData(toParse); //Create new JobData from these files <---- Takes up to a few minutes with hundreds of files.
        CurrentJobData.ToTree(treeView1); //Push this data to the TreeView
    } //Handles the dragdrop of data, populating the solution

Answer 1

您需要让事件运行完成。由于 DragDrop 操作的性质，涉及的两个应用程序都需要确保操作已完成。他们只能判断 DragDrop 消息是否由任一消息泵处理。只要这种情况没有发生，资源管理器就只能假设用户仍在拖放。正如评论中已经建议的那样，使用BackgroundWorker：

private void Form1_DragDrop(object sender, DragEventArgs e)
{    
    // gets all data from Explorer
    string[] files = (string[])e.Data.GetData(DataFormats.FileDrop); //Get the filepaths for the dragdrop data

    // don't block the UI thread, that prevents the 
    // processing of both Windows messages in Explorer and your app
    // to complete, effectively blocking both of them
    backgroundWorker1.RunWorkerAsync(files);

    // if you want your form to be unavailable
    // while processing takes place
    // set Enabled to false on your form
    this.Enabled = false;
}

您作为DoWork事件处理程序现在将承担繁重的工作。请注意我如何设置Result的属性DoWorkEventArgs以将您的 JobData 发送到已完成的事件。

// this all runs on a background, non-UI threed
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
    ClearTempFiles(); //Clear all files before populating

    string[] files = (string[])e.Argument; // this is passed in from RunWorkerAsync

    List<string> toParse = new List<string>();
    foreach (string file in files)
    {
        FileAttributes attr = File.GetAttributes(file);
        if (attr.HasFlag(FileAttributes.Directory)) //If a folder has been included, add all files from within
        {
            toParse.AddRange(DirSearch(file));
        }
        else
        {
            toParse.Add(file); //Add files
        }
    }

    e.Result = new JobData(toParse); //Create new JobData from these files <---- Takes up to a few minutes with hundreds of files.
}

在RunWorkerCompleted事件处理程序中，您返回到 UI 线程，您可以在其中填充和更新您的TreeView. 请注意最后如何再次启用表单，以确保用户可以与应用程序交互。

// this runs on the UI thread
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    CurrentJobData = (JobData) e.Result;

    CurrentJobData.ToTree(treeView1); //Push this data to the TreeView

    // set Enabled to true on your controls
    this.Enabled = true;
}

如果要报告进度，请确保使用 ProgressChanged 事件处理程序，以便您位于 UI 线程上并调用ReportProgress后台工作程序上的方法来调用该处理程序。