在WPF中转到Enter keypress上的下一个控件-Java 学习之路

当我在WPF MVVM应用程序中按Enter键而不是Tab键时，我想转到下一个控件 . 我怎样才能做到这一点？

7 回答

Jay的答案很好，如果你只想让它适用于几个文本框，但如果你希望你的整个应用程序以这种方式工作，我绝对赞成makwana.a的答案 . 这是我对makwana.a在C＃中使用的答案的修改 . 如果活动控件是一个复选框，我还支持通过输入继续下一个控件 .

另请注意，我不使用tag属性来表示焦点是否应继续，而是使用文本框的AcceptsReturn属性，因为它默认为false，您只需在所需的文本框中将其设置为true用作多行，即不应将焦点移到Enter键上 .

在OnStartup void App.xaml中声明这些事件处理程序

EventManager.RegisterClassHandler(typeof(TextBox), TextBox.KeyDownEvent, new KeyEventHandler(TextBox_KeyDown));
        EventManager.RegisterClassHandler(typeof(CheckBox), CheckBox.KeyDownEvent, new KeyEventHandler(CheckBox_KeyDown));

以下是使其适用于应用程序所需的其他方法 .

void TextBox_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter & (sender as TextBox).AcceptsReturn == false) MoveToNextUIElement(e);
    }

    void CheckBox_KeyDown(object sender, KeyEventArgs e)
    {
        MoveToNextUIElement(e);
        //Sucessfully moved on and marked key as handled.
        //Toggle check box since the key was handled and
        //the checkbox will never receive it.
        if (e.Handled == true)
        {
            CheckBox cb = (CheckBox)sender;
            cb.IsChecked = !cb.IsChecked;
        }

     }

    void MoveToNextUIElement(KeyEventArgs e)
    {
        // Creating a FocusNavigationDirection object and setting it to a
        // local field that contains the direction selected.
        FocusNavigationDirection focusDirection = FocusNavigationDirection.Next;

        // MoveFocus takes a TraveralReqest as its argument.
        TraversalRequest request = new TraversalRequest(focusDirection);

        // Gets the element with keyboard focus.
        UIElement elementWithFocus = Keyboard.FocusedElement as UIElement;

        // Change keyboard focus.
        if (elementWithFocus != null)
        {
            if (elementWithFocus.MoveFocus(request)) e.Handled = true;
        }
    }

Edit

我更新了代码，以便在移动成功时将按键标记为已处理，并且还会切换复选框，因为密钥已处理并且将不再到达 .

回复于 2024-04-29T22:14:23+08:00

以下是我用过的附属物 .

一，示例用法：

<TextBox Width="100"
         Text="{Binding Name, Mode=TwoWay}"
         UI:FocusAdvancement.AdvancesByEnterKey="True" />

（UI是我定义以下内容的命名空间别名 . ）

附属物：

public static class FocusAdvancement
{
    public static bool GetAdvancesByEnterKey(DependencyObject obj)
    {
        return (bool)obj.GetValue(AdvancesByEnterKeyProperty);
    }

    public static void SetAdvancesByEnterKey(DependencyObject obj, bool value)
    {
        obj.SetValue(AdvancesByEnterKeyProperty, value);
    }

    public static readonly DependencyProperty AdvancesByEnterKeyProperty =
        DependencyProperty.RegisterAttached("AdvancesByEnterKey", typeof(bool), typeof(FocusAdvancement), 
        new UIPropertyMetadata(OnAdvancesByEnterKeyPropertyChanged));

    static void OnAdvancesByEnterKeyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var element = d as UIElement;
        if(element == null) return;

        if ((bool)e.NewValue) element.KeyDown += Keydown;
        else element.KeyDown -= Keydown;
    }

    static void Keydown(object sender, KeyEventArgs e)
    {
        if(!e.Key.Equals(Key.Enter)) return;

        var element = sender as UIElement;
        if(element != null) element.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
    }
}

你还说"instead of tab,"所以我建议反对它，因为它是一个常见的，众所周知的范例，但如果是这种情况，你可以在附加属性中添加 PreviewKeyDown 处理程序，检查tab键，并设置 Handled = true 为事件args .

回复于 2024-04-29T22:14:23+08:00

示例解决方案：在堆栈面板中使用PreviewKeyDown . 预览...是一个泡沫，因此可以在更高级别处理事件 . 对于不同的元素类型，您可能需要以不同的方式处理它，例如按钮似乎应该保持回车键而不是将注意力更改为回车键 .

这是xaml：

<StackPanel PreviewKeyDown="StackPanel_PreviewKeyDown" >
    <TextBox >
        Hello
    </TextBox>
    <TextBox>
        World
    </TextBox>
    <TextBox>
        test
    </TextBox>
</StackPanel>

以下是代码背后的代码：

private void StackPanel_PreviewKeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.Enter)
    {
        TextBox s = e.Source as TextBox;
        if (s != null)
        {
            s.MoveFocus(new TraversalRequest( FocusNavigationDirection.Next));
        }

        e.Handled = true;
    }
}

这只是一个用于概念验证的沙箱 .

快乐编码......

回复于 2024-04-29T22:14:23+08:00

将此代码写入应用程序文件的onstartup事件中

EventManager.RegisterClassHandler(GetType(TextBox), TextBox.KeyDownEvent, New RoutedEventHandler(AddressOf TextBox_KeyDown))

然后将TextBox_KeyDown sub定义为

Private Sub TextBox_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Input.KeyEventArgs)
    If e.Key = Key.Enter And TryCast(sender, TextBox).Tag <> "1" Then
        ' Creating a FocusNavigationDirection object and setting it to a
        ' local field that contains the direction selected.
        Dim focusDirection As FocusNavigationDirection = FocusNavigationDirection.Next

        ' MoveFocus takes a TraveralReqest as its argument.
        Dim request As New TraversalRequest(focusDirection)

        ' Gets the element with keyboard focus.
        Dim elementWithFocus As UIElement = TryCast(Keyboard.FocusedElement, UIElement)

        ' Change keyboard focus.
        If elementWithFocus IsNot Nothing Then
            elementWithFocus.MoveFocus(request)
        End If
    End If
End Sub

我使用了文本框的“tag”属性来跳过移动焦点 . 即如果有一段时间你不想在按下输入键的情况下移动到下一个控件（在多行文本框的情况下需要输入以创建新行） . 只需将tag属性设置为1即可 .

回复于 2024-04-29T22:14:23+08:00

希望这个帮助：使用AttachedProperty http://madprops.org/blog/enter-to-tab-as-an-attached-property/

public class EnterKeyTraversal
{
    public static bool GetIsEnabled(DependencyObject obj)
    {
        return (bool)obj.GetValue(IsEnabledProperty);
    }

    public static void SetIsEnabled(DependencyObject obj, bool value)
    {
        obj.SetValue(IsEnabledProperty, value);
    }

    static void ue_PreviewKeyDown(object sender, System.Windows.Input.KeyEventArgs e)
    {
        var ue = e.OriginalSource as FrameworkElement;

        if (e.Key == Key.Enter)
        {
            e.Handled = true;
            ue.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
        }
    }

    private static void ue_Unloaded(object sender, RoutedEventArgs e)
    {
        var ue = sender as FrameworkElement;
        if (ue == null) return;

        ue.Unloaded -= ue_Unloaded;
        ue.PreviewKeyDown -= ue_PreviewKeyDown;
    }

    public static readonly DependencyProperty IsEnabledProperty =
        DependencyProperty.RegisterAttached("IsEnabled", typeof(bool),
        typeof(EnterKeyTraversal), new UIPropertyMetadata(false, IsEnabledChanged));

    static void IsEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var ue = d as FrameworkElement;
        if (ue == null) return;

        if ((bool)e.NewValue)
        {
            ue.Unloaded += ue_Unloaded;
            ue.PreviewKeyDown += ue_PreviewKeyDown;
        }
        else
        {
            ue.PreviewKeyDown -= ue_PreviewKeyDown;
        }
    }
}

<StackPanel my:EnterKeyTraversal.IsEnabled="True">

回复于 2024-04-29T22:14:23+08:00

1

首先发生的事件是向 PreviewKeyDown 触发时将调用的每个元素添加触发器 . 还要添加Dependency属性并绑定 FrameworkElement ，您不会将焦点放在 . 在触发器内提供绑定元素的设置 Focus .

回复于 2024-04-29T22:14:23+08:00

使用代码隐藏：

我想出了下面的代码 . 请注意，它没有设置e.Handled . 此外，MoveFocus_Next不会返回移动焦点是否成功，而是返回参数是否为空 . 您可以根据需要添加或删除要处理的控件类型 . 代码是为应用程序的MainWindow编写的，但也处理其他窗口 . 您还可以从App_Startup事件调整代码以进行调用 .

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

public partial class MainWindow : Window
{
    private bool MoveFocus_Next(UIElement uiElement)
    {
        if (uiElement != null)
        {
            uiElement.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
            return true;
        }
        return false;
    }

    public MainWindow()
    {
        InitializeComponent();
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        EventManager.RegisterClassHandler(typeof(Window), Window.PreviewKeyUpEvent, new KeyEventHandler(Window_PreviewKeyUp));
    }

    private void Window_PreviewKeyUp(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter)
        {
            IInputElement inputElement = Keyboard.FocusedElement;
            if (inputElement != null)
            {
                System.Windows.Controls.Primitives.TextBoxBase textBoxBase = inputElement as System.Windows.Controls.Primitives.TextBoxBase;
                if (textBoxBase != null)
                {
                    if (!textBoxBase.AcceptsReturn)
                        MoveFocus_Next(textBoxBase);
                    return;
                }
                if (
                    MoveFocus_Next(inputElement as ComboBox)
                    ||
                    MoveFocus_Next(inputElement as Button)
                    ||
                    MoveFocus_Next(inputElement as DatePicker)
                    ||
                    MoveFocus_Next(inputElement as CheckBox)
                    ||
                    MoveFocus_Next(inputElement as DataGrid)
                    ||
                    MoveFocus_Next(inputElement as TabItem)
                    ||
                    MoveFocus_Next(inputElement as RadioButton)
                    ||
                    MoveFocus_Next(inputElement as ListBox)
                    ||
                    MoveFocus_Next(inputElement as ListView)
                    ||
                    MoveFocus_Next(inputElement as PasswordBox)
                    ||
                    MoveFocus_Next(inputElement as Window)
                    ||
                    MoveFocus_Next(inputElement as Page)
                    ||
                    MoveFocus_Next(inputElement as Frame)
                )
                    return;
            }
        }
    }
}

回复于 2024-04-29T22:14:23+08:00

在WPF中转到Enter keypress上的下一个控件

7 回答

使用代码隐藏：

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