Question

我正在实现一个ProgressBar，它在完成每个任务（总共5个任务）之后进行更新。每个完成的任务后，它应更新20％。单击按钮即可开始运行任务，但是单击该按钮时进度条会从0％变为100％，而不会在两者之间进行更新。在进度值的每个增量之前添加Thread.Sleep（1000），以模拟每个任务将花费的时间。在添加每个任务的代码之前，我想让进度条正常工作。

我尝试添加AvaloniaPropertyChanged事件，但似乎并不能解决问题。

MainWindow.xaml：

<ProgressBar Name="RunProgress" Value="{Binding Progress}" IsIndeterminate="False" Minimum="0" Maximum="100" Height="30"/>
<TextBlock Text="{Binding ElementName=RunProgress, Path=Value, StringFormat={}{0:0}%}" HorizontalAlignment="Center" VerticalAlignment="Center" />

MainWindow.xaml.cs：

//boolean variables for whether or not that process is completed (false if not done, true if done)
bool MasterLimitsRead = false;
bool MasterOrganized = false;
bool LimitsOrganized = false;
bool RemovedFailed = false;
bool OutputCreated = false;

//holds descriptions of the 5(+1) operations the program runs through including description for Done
string[] operation =
{
   "Reading the master and limits file text",
   "Organizing the master data",
   "Organizing the limits",
   "Identifying and removing failed devices",
   "Creating the output",
   "Done"
};

context.CurrentOp = operation[0];

Thread.Sleep(1000);
MasterLimitsRead = true;
if(MasterLimitsRead == true)
{
   context.Progress += 20;
   context.CurrentOp = operation[1];
}

Thread.Sleep(1000);
MasterOrganized = true;
if(MasterOrganized == true)
{
   context.Progress += 20;
   context.CurrentOp = operation[2];
}

Thread.Sleep(1000);
LimitsOrganized = true;
if(LimitsOrganized == true)
{
   context.Progress += 20;
   context.CurrentOp = operation[3];
}

Thread.Sleep(1000);
RemovedFailed = true;
if(RemovedFailed == true)
{
   context.Progress += 20;
   context.CurrentOp = operation[4];
}

Thread.Sleep(1000);
OutputCreated= true;
if(OutputCreated== true)
{
   context.Progress += 20;
   context.CurrentOp = operation[5];
}

MainWindowViewModel.cs：

private string currentOp = string.Empty;   //variable to store current operation, initialized to empty string
public string CurrentOp
{
   get => currentOp;
   set
   {
      if (value != currentOp)
      {
         currentOp = value;
         OnPropertyChanged();
      }
    }
}

private string progress = 0;   //variable to store ProgressBar value in percent, initialized to 0
public string CurrentOp
{
   get => currentOp;
   set
   {
      if (value != currentOp)
      {
         currentOp = value;
         OnPropertyChanged();
      }
    }
}

public event PropertyChangedEventHandler PropertyChanged;

protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
   if(PropertyChanged != null)
   {
      PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
   }
}

期望：进度条应在每个任务完成后从0％增加到100％，并增加20％（由Thread.Sleep（1000）延迟1秒来模拟）

实际：进度条从0％开始，然后单击按钮，暂停UI交互5秒钟，然后将进度条更新为100％。我希望它在进度栏的每个值增量时更新。

Answer 1

通过调用Sleep，您正在阻止UI线程。如果UI线程被阻止，则不会进行任何UI更新。要模拟长时间运行的任务，请改用await Task.Delay(TimeSpan.FromSeconds(1))。

进度栏从0％跳到100％，而之间没有更新

1 个答案: