WPF：每半秒更換網格背景並仍然與其他控件交互

Question

希望網格背景每半秒由提供的r，g，b值進行更改，並且仍然能夠與網格內的按鈕進行交互。 問題是背景在regualr時間間隔上都沒有變化，也不允許用戶與網格中的兩個按鈕進行交互。只有當我切換到任何其他應用程序或任務管理器時，網格的顏色纔會更改。如何達到目標？

<Grid Name="MainGrid" Height="{Binding ElementName=MainWindow1, Path=ActualHeight}" Loaded="MainGrid_Loaded"> 
    <StackPanel VerticalAlignment="Center"> 
     <Label Height="50" Name="xCoordinate" /> 
     <Label Height="50" Name="yCoordinate" /> 
     <StackPanel HorizontalAlignment="Center" Height="50" Orientation="Horizontal"> 
      <Button Content="Red" Width="100" Name="xBtn" Click="xBtn_Click" Margin="0,0,10,0"/> 
      <Button Content="Blue" Width="100" Name="yBtn" Click="yBtn_Click" /> 
     </StackPanel> 
    </StackPanel> 
</Grid> 

public partial class MainWindow : Window 
{ 
    Thread thread; 
    public MainWindow() 
    { 
     InitializeComponent(); 
     thread = new Thread(new ThreadStart(ChangeGridColor)); 
     thread.Start(); 

    } 

    private void xBtn_Click(object sender, RoutedEventArgs e) 
    { 
     xCoordinate.Background = new SolidColorBrush(Colors.Red); 
    } 

    private void yBtn_Click(object sender, RoutedEventArgs e) 
    { 
     yCoordinate.Background = new SolidColorBrush(Colors.Blue); 
    } 

    private void MainWindow_MouseMove(object sender, MouseEventArgs e) 
    { 
     Point point = Mouse.GetPosition(Application.Current.MainWindow); 
     xCoordinate.Content = point.X; 
     yCoordinate.Content = point.Y; 

    } 

    byte r=0,g=0,b = 0; 
    public void ChangeGridColor() 
    { 
     while (true) 
     { 
      this.Dispatcher.Invoke((Action)(() => 
      {//this refer to form in WPF application 
       MainGrid.Background = new SolidColorBrush(Color.FromRgb(r, g, b)); 
       r += 1; 
       g += 1; 
       b += 1; 
      })); 

      Thread.Sleep(1000); 
     } 
    } 
} 

Answer 1

你不需要第二個線程來睡覺。你可以使用一個計時器。定時器在給定的時間間隔內調用回調。

public partial class MainWindow : Window 
{ 
    private readonly System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer() 

    public MainWindow() 
    { 
     InitializeComponent(); 
     _timer.Interval = 500; // 500ms. 
     _timer.Elapsed += ElapsedCallback; 
     _timer.Start(); 
    } 

    private void ElapsedCallback(object sender, EventArgs e) 
    { 
     MainGrid.Background = new SolidColorBrush(Color.FromRgb(r, g, b)); 
     r = ++r % 0xFF; // prevent overlfow. 
     g = ++g % 0xFF; 
     b = ++g % 0xFF; 
    } 

    private void xBtn_Click(object sender, RoutedEventArgs e) 
    { 
     xCoordinate.Background = new SolidColorBrush(Colors.Red); 
    } 

    private void yBtn_Click(object sender, RoutedEventArgs e) 
    { 
     yCoordinate.Background = new SolidColorBrush(Colors.Blue); 
    } 

    private void MainWindow_MouseMove(object sender, MouseEventArgs e) 
    { 
     Point point = Mouse.GetPosition(Application.Current.MainWindow); 
     xCoordinate.Content = point.X; 
     yCoordinate.Content = point.Y; 

    } 
} 

Answer 2

您的代碼應該表現爲，如果你在後臺線程執行你的循環，你會期望：

byte r = 0, g = 0, b = 0; 
public void ChangeGridColor() 
{ 
    Task.Run(() => 
    { 
     while (true) 
     { 
      this.Dispatcher.Invoke((Action)(() => 
      { 
       MainGrid.Background = new SolidColorBrush(Color.FromRgb(r, g, b)); 
      })); 

      r += 1; 
      g += 1; 
      b += 1; 
      Thread.Sleep(1000); 
     } 
    }); 
}