保持焦點在WPF中的自定義（用戶）控件

Question

說，我需要使用鍵盤在窗體中移動自定義（用戶）控件。

行爲很簡單：用戶單擊控件，然後使用鍵盤（up/d/l/r）移動它。

在此示例中，而不是UserControl，我將使用Canvas。

的問題是，當我「合焦點」我的控制，或者我失去它的「階梯」對TextBox政變後，還是我不接受她在所有...

XAML：

<Window x:Class="WpfApplication14.MainWindow" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     Title="MainWindow" Height="350" Width="525" 
     PreviewKeyDown="Window_PreviewKeyDown"> 
    <Grid> 
     <TextBox Name="textBox1" 
       Margin="91,66,292,223" Width="120" 
       Text="Good morning, miss Hilton!"/> 
     <Canvas Name="canvas1" Focusable="True" 
       Margin="124,112,179,99" Width="200" 
       Background="AliceBlue" 
       MouseDown="canvas1_MouseDown" 
       PreviewKeyDown="canvas1_PreviewKeyDown" /> 
    </Grid> 
</Window> 

CS：

public partial class MainWindow : Window 
{ 
    public MainWindow() 
    { 
     InitializeComponent(); 
    } 

    private void canvas1_MouseDown(object sender, MouseButtonEventArgs e) 
    { 
     Console.WriteLine("canvas_MouseDown 0, canvas1.IsFocused? {0}", 
      canvas1.IsFocused); 

     canvas1.Focus(); 

     Console.WriteLine("canvas_MouseDown 1, canvas1.IsFocused? {0}", 
      canvas1.IsFocused); 
    } 

    private void canvas1_PreviewKeyDown(object sender, KeyEventArgs e) 
    { 
     Console.WriteLine("canvas_PreviewKeyDown, canvas1.IsFocused? {0}", 
      canvas1.IsFocused); 

     if (canvas1.IsFocused) 
      MoveCanvas(e.Key); 
    } 

    private void Window_PreviewKeyDown(object sender, KeyEventArgs e) 
    { 
     //Console.WriteLine("Window_PreviewKeyDown, canvas1.IsFocused? {0}", 
     // canvas1.IsFocused); 

     //if (canvas1.IsFocused) 
     // MoveCanvas(e.Key); 
    } 

    void MoveCanvas(Key key) 
    { 
     int delta = 10; 
     switch (key) 
     { 
      case Key.Left: canvas1.Margin = new Thickness(
       canvas1.Margin.Left - delta, 
       canvas1.Margin.Top, 
       canvas1.Margin.Right, 
       canvas1.Margin.Bottom); 
       break; 
      case Key.Up: canvas1.Margin = new Thickness(
       canvas1.Margin.Left, 
       canvas1.Margin.Top - delta, 
       canvas1.Margin.Right, 
       canvas1.Margin.Bottom + delta); 
       break; 
      case Key.Right: canvas1.Margin = new Thickness(
       canvas1.Margin.Left, 
       canvas1.Margin.Top, 
       canvas1.Margin.Right - delta, 
       canvas1.Margin.Bottom); 
       break; 
      case Key.Down: canvas1.Margin = new Thickness(
       canvas1.Margin.Left, 
       canvas1.Margin.Top + delta, 
       canvas1.Margin.Right, 
       canvas1.Margin.Bottom - delta); 
       break; 
      default: 
       break; 
     } 
    } 
} 

貝婁是按下鼠標的控制和三個 「使用keyUp」 S後執行日誌：

canvas_MouseDown 0, canvas1.IsFocused? False ' before click ' 
    canvas_MouseDown 1, canvas1.IsFocused? True ' after click ' 
Window_PreviewKeyDown, canvas1.IsFocused? True ' up 1 ' 
canvas_PreviewKeyDown, canvas1.IsFocused? True ' up 1 ' 
Window_PreviewKeyDown, canvas1.IsFocused? False ' up 2 ' 
Window_PreviewKeyDown, canvas1.IsFocused? False ' up 3 ' 

Answer 1

有兩件事情可以嘗試：

1. 集如果交給事件e.Handled爲true。這應該防止其他事物對關鍵中風作出反應。

2. 您可能需要在所有祖先控件上使用KeyboardNavigation.DirectionalNavigation設置。箭頭鍵默認會移動鍵盤焦點，但這是基於DirectionalNavigation設置的。你想把它設置爲None，但是這是假設＃1不能解決問題。