使用标签描述表单的状态

本文关键字:状态 表单 描述 标签 | 更新日期: 2023-09-27 18:34:53

我遇到一种情况,我只需要一个标签,当用户单击按钮时,该标签可以在"就绪"和"进行中"之间切换。标签最初处于"就绪"状态。当用户单击按钮时,标签应显示为"正在进行",然后需要执行一些任务,例如复制文件等。成功完成任务后,标签应再次显示为"就绪"。现在我正在使用这段代码,标签状态没有改变。我怎样才能做到这一点。请帮忙。

 private void button1_Click(object sender, EventArgs e)
 {
        status.Text = "In Progress";
        if (listBox1.Items.Count == 0)
        {
            MessageBox.Show("Please select a file to upload");
        }
        FtpClient client = new FtpClient("*******", "*******", "******");
        string fileName = getFileNameFromPath(listBox1.Items[0].ToString());
        string localFile = listBox1.Items[0].ToString();
        string remoteFile = "**********/"+fileName;
        string link = client.upload(remoteFile, localFile);
        listBox1.Items.RemoveAt(0);
        textBox1.Text = link; 
        status.Text = "Ready";  
  }

使用标签描述表单的状态

你在长时间运行的过程中阻止了 UI 线程,既阻止了 UI 更新文本值,要么接收用户输入,要么执行任何操作。

您需要异步执行长时间运行的工作,以免阻塞 UI 线程。

理想情况下,您将拥有FtpClient提供的异步方法(甚至更好的是,它会返回一个Task(。 这将允许你写这样的东西:

private async void button1_Click(object sender, EventArgs e)
{
    status.Text = "In Progress";
    if (listBox1.Items.Count == 0)
    {
        MessageBox.Show("Please select a file to upload");
    }
    FtpClient client = new FtpClient("*******", "*******", "******");
    string fileName = getFileNameFromPath(listBox1.Items[0].ToString());
    string localFile = listBox1.Items[0].ToString();
    string remoteFile = "**********/" + fileName;
    string link = await client.uploadAsync(remoteFile, localFile);
    listBox1.Items.RemoveAt(0);
    textBox1.Text = link;
    status.Text = "Ready";
}

然后你就完成了。 如果它不提供任何异步方法,那么作为解决方法,您只需启动一个新任务即可在后台完成工作:

private async void button1_Click(object sender, EventArgs e)
{
    status.Text = "In Progress";
    if (listBox1.Items.Count == 0)
    {
        MessageBox.Show("Please select a file to upload");
    }
    FtpClient client = new FtpClient("*******", "*******", "******");
    string fileName = getFileNameFromPath(listBox1.Items[0].ToString());
    string localFile = listBox1.Items[0].ToString();
    string remoteFile = "**********/" + fileName;
    string link = await Task.Run(() => client.upload(remoteFile, localFile));
    listBox1.Items.RemoveAt(0);
    textBox1.Text = link;
    status.Text = "Ready";
}

如果您没有 C# 5.0 和 .NET 4.5 可以使用await则可以使用BackgroundWorker

private void button1_Click(object sender, EventArgs e)
{
    status.Text = "In Progress";
    if (listBox1.Items.Count == 0)
    {
        MessageBox.Show("Please select a file to upload");
    }
    string fileName = getFileNameFromPath(listBox1.Items[0].ToString());
    string localFile = listBox1.Items[0].ToString();
    string remoteFile = "**********/" + fileName;
    var worker = new BackgroundWorker();
    worker.DoWork += (s, args) =>
    {
        FtpClient client = new FtpClient("*******", "*******", "******");
        args.Result =  client.upload(remoteFile, localFile);
    };
    worker.RunWorkerCompleted += (s, args) =>
    {
        listBox1.Items.RemoveAt(0);
        textBox1.Text = args.Result as string;
        status.Text = "Ready";
    };
    worker.RunWorkerAsync();
}