c# - 表单在 backgroundworker 中不显示为对话框？

Question

Form 没有在 backgroundworker 中显示为 Dialog？

这是我的代码:

//From Form1
        private void backgroundWorkerResult_DoWork(object sender, DoWorkEventArgs e)
    {
        //do something here

        backgroundWorkerResult.ReportProgress(100);

        frmMessageBox frmMsgBox = new frmMessageBox();
        frmMsgBox.ShowDialog();
    }

即使我已经将 frmMsgBox 显示为对话框，我仍然可以单击应该不是的 Form1 吗？如何解决这个问题？

Answer 1

我创建了一个简单的代码示例，您可以使用它来了解后台工作人员的工作方式。将代码复制到测试窗体中，并添加以下控件

1. 标签控件 - 将其命名为“lblStatus”
2. 进度条控件 - 它应该命名为 progressBar1。
3. 添加两个名为“btnStartAsyncOperation”和“btnCancel”的按钮，并链接它们的点击事件。

基本上您应该在RunWorkerCompleted 事件中显示结果

    public partial class Form1 : Form
    {
        BackgroundWorker backgroundWorker;

        public Form1()
        {
            InitializeComponent();
            backgroundWorker = new BackgroundWorker {WorkerReportsProgress = true, WorkerSupportsCancellation = true};

            backgroundWorker.DoWork += new DoWorkEventHandler(BackgroundWorker_DoWork);
            backgroundWorker.ProgressChanged += new ProgressChangedEventHandler(BackgroundWorker_ProgressChanged);
            backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(BackgroundWorker_RunWorkerCompleted);

        }

        void BackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (e.Cancelled)
                lblStatus.Text = "Task Cancelled.";
            else if (e.Error != null)
                lblStatus.Text = "Error - " + e.Error.Message;
            else
                lblStatus.Text = "Task Completed...";

            btnStartAsyncOperation.Enabled = true;
            btnCancel.Enabled = false;
        }

        void BackgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            progressBar1.Value = e.ProgressPercentage;
            lblStatus.Text = "Processing......" + progressBar1.Value.ToString() + "%";
        }

        void BackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
        {
            for (int i = 0; i < 100; i++)
            {
                System.Threading.Thread.Sleep(100);
                backgroundWorker.ReportProgress(i);
                if (backgroundWorker.CancellationPending)
                {
                    e.Cancel = true;
                    backgroundWorker.ReportProgress(0);
                    return;
                }
            }
            backgroundWorker.ReportProgress(100);
        }

        private void btnStartAsyncOperation_Click(object sender, EventArgs e)
        {
            btnStartAsyncOperation.Enabled = false;
            btnCancel.Enabled = true;
            backgroundWorker.RunWorkerAsync();
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            if (backgroundWorker.IsBusy)
            {
                backgroundWorker.CancelAsync();
            }
        }
    }

根据 OP 的评论编辑

在 DoWork 事件中，按如下方式设置您的字符串

 e.Result = "Your String";

并在 RunWorkerCompleted 事件中

string muResult = Convert.ToString(e.Result);

注意: e.Result 是一个对象，因此您甚至可以在其中设置具有多个属性的自定义类。