Question

我有一个可以登录的表单，可能需要一段时间才能将数据加载到表单中。因此，我想在加载表单时创建一个带有进度条的单独表单（loadScreen.cs）。我在loadScreen.cs表单中尝试了这个：

 private void Form1_Load(object sender, EventArgs e)
 {
   worker = new BackgroundWorker();
   worker.WorkerReportsProgress = true;
   worker.WorkerSupportsCancellation = true;

   worker.DoWork += new DoWorkEventHandler(worker_DoWork);
   worker.ProgressChanged +=
          new ProgressChangedEventHandler(worker_ProgressChanged);
   worker.RunWorkerCompleted +=
         new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
 }



 void worker_DoWork(object sender, DoWorkEventArgs e)
 {
   int percentFinished = (int)e.Argument;
   while (!worker.CancellationPending && percentFinished < 100)
 {
   percentFinished++;
   worker.ReportProgress(percentFinished);
   System.Threading.Thread.Sleep(50);
 }
 e.Result = percentFinished;
 }


 void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
 {
   progressBar1.Value = e.ProgressPercentage;
 }


 void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
 {
  this.Close();
  }

我已经读过，worker_DoWork方法应该具有加载时间更长的代码。因为我的按钮在Form1中，所以我不知道如何处理这个问题。当它被点击时，我会带着

进入另一个班级

  private void signIn_Click(object sender, EventArgs e)
    {
        var logIn = new LogIn(this);
        logIn.checkUserInput(this);
    }

然后我执行加载某些东西的操作。如何连接一切？我需要帮助！

Answer 1

我实际上正在为这类事情创建一个通用对话。它没有及时准备好对你有用，但我建议你按照类似的方针行事。创建你的＆＃34; Loading＆＃34;对话，以便它接受委托并在DoWork事件处理程序中调用它。然后，主窗体可以包含一个执行工作的方法，您可以将该方法的委托传递给对话。我将发布一个非常基本的例子。

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private DataTable table;

    private void button1_Click(object sender, EventArgs e)
    {
        var work = new Action(GetData);

        using (var f2 = new Form2(work))
        {
            f2.ShowDialog();
            this.dataGridView1.DataSource = this.table;
        }
    }

    private void GetData()
    {
        this.table = new DataTable();

        using (var adapter = new SqlDataAdapter("SELECT * FROM MyTable", "connectionstring here"))
        {
            adapter.Fill(table);
        }
    }
}


public partial class Form2 : Form
{
    private Action work;

    public Form2(Action work)
    {
        InitializeComponent();

        this.work = work;
    }

    private void Form2_Load(object sender, EventArgs e)
    {
        this.backgroundWorker1.RunWorkerAsync();
    }

    private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        this.work();
    }

    private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        this.DialogResult = DialogResult.OK;
    }
}

请注意，在使用数据适配器时没有真正的方法来衡量进度，因此在这种情况下您只能真正显示选框进度条。

在Winforms的背景工作者装货屏幕

1 个答案: