如何在 UI 中为组合键显示按钮被按下

Question

其实这篇文章和this（也是我发的）不同。我的 UI 中有一个电话键盘，现在我可以显示按下相应键时按下的按钮。

private void NumDisplayBox_PreviewKeyDown(object sender, KeyEventArgs e)
{
  switch (e.Key) 
  {
    case Key.D0:
    case Key.NumPad0:
      ZeroBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D1:
    case Key.NumPad1:
      OneBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D2:
    case Key.NumPad2:
      TwoBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D3:
    case Key.NumPad3:
      ThreeBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D4:
    case Key.NumPad4:
      FourBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D5:
    case Key.NumPad5:
      FiveBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D6:
    case Key.NumPad6:
      SixBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D7:
    case Key.NumPad7:
      SevenBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D8:
    case Key.NumPad8:
      EightBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
    case Key.D9:
    case Key.NumPad9:
      NineBtn.Style = (Style) FindResource("PressedButtonStyle");
      break;
  }

  if (((Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift))
  {
    if (e.Key == Key.D3)
    {
      ThreeBtn.Style = (Style)FindResource("NormalButtonStyle");
      HashBtn.Style = (Style)FindResource("PressedButtonStyle");
    }
  }
}

private void NumDisplayBox_PreviewKeyUp(object sender, KeyEventArgs e) 
{
  switch (e.Key) 
  {
    case Key.D0:
    case Key.NumPad0:
      ZeroBtn.Style = (Style) FindResource("ButtonStyle4"); break;
    case Key.D1:
    case Key.NumPad1:
      OneBtn.Style = (Style) FindResource("ButtonStyle4"); break;

    .
    .
    .
  }
}

问题是当哈希键 (Shift + 3) 或星号键 (Shift + 8) 按下时，在 UI 中也会按下“3”按钮（用于大小写哈希键）。如何显示当 Shift + 3 按下时在 UI 上只按下哈希按钮，而不是哈希按钮和“3”按钮？

Answer 1

检查KeyEventArgs.Modifiers 属性，仅在未设置修饰符时处理按键。

或者，使用TextInput 或PreviewTextInput 事件来获取组合文本而不是实际密钥。无论如何，这可能更可取，因为它将响应输入适当文本输入的任何方法，而不是依赖于特定键（例如，您不必为所有可能的键设置大小写，例如顶部-行数字键和数字键盘键，就像现在一样）。

Answer 2

这对我有用：

//Make the button to have "pressed" feel when the corresponding key is pressed

private void NumDisplayBox_PreviewKeyDown(object sender, KeyEventArgs e) 
{
    if (((Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift))
    {
      if (e.Key == Key.D3)
        HashBtn.Style = (Style) FindResource("PressedButtonStyle");

      if (e.Key == Key.D8)
        StarBtn.Style = (Style) FindResource("PressedButtonStyle");
    }

    switch (e.Key) 
    {
      case Key.D0:
      case Key.NumPad0:
        ZeroBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      case Key.D1:
      case Key.NumPad1:
        OneBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      case Key.D2:
      case Key.NumPad2:
        TwoBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      case Key.D3:
      case Key.NumPad3:
        {
          if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
            ThreeBtn.Style = (Style) FindResource("ButtonStyle4");

          else
            ThreeBtn.Style = (Style) FindResource("PressedButtonStyle");

          break;
        }
      case Key.D4:
      case Key.NumPad4:
        FourBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      case Key.D5:
      case Key.NumPad5:
        FiveBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      case Key.D6:
      case Key.NumPad6:
        SixBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      case Key.D7:
      case Key.NumPad7:
        SevenBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      case Key.D8:
      case Key.NumPad8:
        {
          if (Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift))
            EightBtn.Style = (Style) FindResource("ButtonStyle4");

          else
            EightBtn.Style = (Style) FindResource("PressedButtonStyle");

          break;
        }
      case Key.D9:
      case Key.NumPad9:
        NineBtn.Style = (Style) FindResource("PressedButtonStyle");
        break;
      default:
        break;
    }
}

//Return back to its original style

private void NumDisplayBox_PreviewKeyUp(object sender, KeyEventArgs e)
{
  switch (e.Key) 
  {
    case Key.D0:
    case Key.NumPad0:
      ZeroBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D1:
    case Key.NumPad1:
      OneBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D2:
    case Key.NumPad2:
      TwoBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D3:
    case Key.NumPad3:
      ThreeBtn.Style = (Style) FindResource("ButtonStyle4");
      HashBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D4:
    case Key.NumPad4:
      FourBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D5:
    case Key.NumPad5:
      FiveBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D6:
    case Key.NumPad6:
      SixBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D7:
    case Key.NumPad7:
      SevenBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D8:
    case Key.NumPad8:
      EightBtn.Style = (Style) FindResource("ButtonStyle4");
      StarBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    case Key.D9:
    case Key.NumPad9:
      NineBtn.Style = (Style) FindResource("ButtonStyle4");
      break;
    default:
      break;
  }
}