Question

我正在尝试检查程序的更新。
我面临的问题是Thread.Sleep或Task.Delays被完全忽略了。
在CheckUpdate()，我等待5秒钟，然后显示“登录”表单，但是在我的情况下，当我调试程序时，它首先等待5秒钟，然后如果不需要更新，它将在第一个表单中直接打开第二个表单显示一个我尝试在代码中到处都执行Thread.Sleeps，但这只会使它更长，以显示实际的第一种形式，我尝试使用console进行调试，并使用console.writeline查看是否正确完成了睡眠，但情况确实如此与UI相关的东西无法正常工作，这就是为什么我在这里寻求帮助的原因，如果这听起来很愚蠢，并且我知道Thread.Sleep不应该使用，因为它冻结了UI，但是我一直使用的方式，我深表歉意过去，只要更新表单标签或其他任何内容，它就可以毫无问题地正常工作。

public partial class PreForm : Form
{
    public PreForm()
    {
        InitializeComponent();
        CheckRights();
    }

    private void CheckRights()
    {
        HttpWebRequest.DefaultWebProxy = new WebProxy();
        try
        {
            File.Create(@"C:\Users\Default\AppData\Local\Temp\SimpleTempFile.tmp");
        }
        catch (Exception)
        {
            MessageBox.Show("Error code : #0001.\nCheck for our knowledge base for more informations.", "Error code : #0001");
            Environment.Exit(0);
        }

        CheckUpdate();
    }

    private void CheckUpdate()
    {
        WebClient Update = new WebClient();

        if (Update.DownloadString("https://RandomSiteWithString.txt").Contains("1.1"))
        {

            TextBar.Text = "Using latest version..";
            Thread.Sleep(5000);
            Login F2 = new Login();
            F2.Show();

        }
        else
        {

            Console.WriteLine("Downloading");

            TextBar.Text = "An update is being downloaded..";

            StartDownload();

        }
    }



    private void StartDownload()
    {
        Thread thread = new Thread(() =>
        {
            Stopwatch sw = new Stopwatch();
            WebClient webClient;

            using (webClient = new WebClient())
            {
                webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
                webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);


                // Start the stopwatch which we will be using to calculate the download speed
                sw.Start();

                try
                {
                    // Start downloading the file
                    webClient.DownloadFileAsync(new Uri("http://siteofupdated.exe"), "XXXXX_Update.exe");
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        });
        thread.Start();

    }

    // The event that will fire whenever the progress of the WebClient is changed
    private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e)
    {
        this.BeginInvoke((MethodInvoker)delegate
        {


            // Update the progressbar percentage only when the value is not the same.
            TaskBar.Value = e.ProgressPercentage;



            // Update the label with how much data have been downloaded so far and the total size of the file we are currently downloading
            TextBar.Text = string.Format("{0} MB's / {1} MB's",
                (e.BytesReceived / 1024d / 1024d).ToString("0.00"),
                (e.TotalBytesToReceive / 1024d / 1024d).ToString("0.00"));
        });

    }

    // The event that will trigger when the WebClient is completed
    private void Completed(object sender, AsyncCompletedEventArgs e)
    {
        this.BeginInvoke((MethodInvoker)delegate
        {

            Stopwatch sw = new Stopwatch();
            // Reset the stopwatch.
            sw.Reset();

            if (e.Cancelled == true)
            {
                MessageBox.Show("Download has been canceled.");
            }
            else
            {
                MessageBox.Show("Download completed!");
                Process.Start("XXXXXX_Update.exe");
                Environment.Exit(0);
            }
        });
    }
}

Answer 1

在构造函数完成运行之前，不会显示PreForm表单，因此您需要从那里进行对CheckRights()的调用。

最简单的方法是将事件处理程序添加到Shown事件中，然后将调用放在此处。

使用Thread.Sleep或Task.Delay似乎不适用于我的代码

1 个答案: