使 Userdialog.Instance.Progress 等待方法执行 C# Xamarin 的好方法

Question

我正在尝试显示一个进度对话框，显示使用等待所有内容的方法完成的百分比 + await Task.Delay(20); 和等待我要执行的方法。现在我注意到使用 task.delay 执行需要更长的时间。

我想要实现的是 progress.dialog 计算该方法需要多长时间而不是延迟它，因为它的工作速度要慢一些。

我有哪些选择？

这是我的代码

    private async Task DownloadAllAlert()
    {
        //alert to download everything
        bool result = await DisplayAlert("Download", "Do you want to download everything?", "Yes", "No"); ;

        //alert is user chose yes
        if (result)
        {
            // loading dialog in percentage till downloading is done
            using (var progress = UserDialogs.Instance.Progress("Loading..."))
            {
                for (var i = 0; i < 100; i++)
                {
                    progress.PercentComplete = i;
                    await Api.DownloadAll();
                    await Task.Delay(20);
                }
            }
        }
    }

Answer 1

尝试在 c# 中使用 Task。

using (var progress = UserDialogs.Instance.Progress("Loading..."))
{
    await LoadData(ref progress);
}

调用这个函数

public async Task LoadData(ref IProgressDialog progress);
{
  //await Task.Yield(); //add this line of code if on ios didnt work
  
 Task task1 = new Task(() =>
    {
        for (int i = 0; i < 50 ; i++) // loop untill 50% then increase sleeping thread time
        {
            progress.PercentComplete = i;     
            //sleeping for 1 second  
            Thread.Sleep(1000);
        }
        for (int i = 50; i < 100; i++) // loop untill 99% then stop
        {
            progress.PercentComplete = i;     
            //sleeping for 2 second  
            Thread.Sleep(2000);
        }
        Console.WriteLine("Task 1 complete");
    });

    Task task2 = new Task(() =>
    {
        await Api.DownloadAll();
        Console.WriteLine("Task 2 complete");
    });

    //starting the tasks  
    task1.Start();
    task2.Start();
    Task.WaitAny(task2);
    progress.PercentComplete = 100; // when task2 finish put it 100%
}