Select 应用程序中所有文本框的 TextBox 中的所有文本

Question

我想让我的 Windows 10 通用应用程序中的所有文本框在获得焦点时自动 select 所有文本。很像这样 here (WPF)。这在 UWP 中可行吗？

Answer 1

有多种方法可以实现这一点，但这里有一个：只需扩展现有的 TextBox 控件并在任何地方使用它。

public class SelectableTextBox : TextBox
{
    public SelectableTextBox()
    {
        this.GotFocus += SelectableTextBox_GotFocus;
    }

    private void SelectableTextBox_GotFocus(object sender, RoutedEventArgs e)
    {
        this.SelectAll();
    }
}

XAML:

<local:SelectableTextBox Text="This is some text."/>

这是另一种方法。写一个行为！

public class SelectAllTextBoxBehavior : DependencyObject, IBehavior
{
    private TextBox textBox;

    public DependencyObject AssociatedObject
    {
        get
        {
            return this.textBox;
        }
    }

    public void Attach(DependencyObject associatedObject)
    {
        if (associatedObject is TextBox)
        {
            this.textBox = associatedObject as TextBox;
            this.textBox.GotFocus += TextBox_GotFocus;
        }
    }

    public void Detach()
    {
        if (this.textBox != null)
        {
            this.textBox.GotFocus -= TextBox_GotFocus;
        }
    }

    private void TextBox_GotFocus(object sender, RoutedEventArgs e)
    {
        this.textBox.SelectAll();
    }
}

并将其附加到每个文本框。

<TextBox Text="This is some text.">
    <i:Interaction.Behaviors>
        <local:SelectAllTextBoxBehavior />
    </i:Interaction.Behaviors>
</TextBox>

您需要将 Behaviors SDK 添加到您的项目中才能使用第二个选项。

Answer 2

我会用 AttachedProperty

的附加行为来做到这一点

像这样：一个 class 来保存 bool 类型的属性并且在更改时是 attaching/detaching 焦点事件的处理程序

public static class TextBoxAttached
{
    public static bool GetAutoSelectable(DependencyObject obj)
    {
        return (bool)obj.GetValue(AutoSelectableProperty);
    }

    public static void SetAutoSelectable(DependencyObject obj, bool value)
    {
        obj.SetValue(AutoSelectableProperty, value);
    }

    public static readonly DependencyProperty AutoSelectableProperty =
        DependencyProperty.RegisterAttached(
            "AutoSelectable",
            typeof(bool),
            typeof(TextBoxAttached),
            new PropertyMetadata(false, AutoFocusableChangedHandler));

    private static void AutoFocusableChangedHandler(
        DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if(e.NewValue != e.OldValue)
        {
            if((bool)e.NewValue == true)
            {
                (d as TextBox).GotFocus += OnGotFocusHandler;
            }
            else
            {
                (d as TextBox).GotFocus -= OnGotFocusHandler;
            }
        }
    }

    private static void OnGotFocusHandler(object sender, RoutedEventArgs e)
    {
        (sender as TextBox).SelectAll();
    }
}

用法：XAML

<TextBox Text="Test" local:TextBoxAttached.AutoSelectable="True"/>

编辑

您还可以定义默认样式，使所有 TextBox 都可以自动选择

<Page.Resources>
    <Style TargetType="TextBox" >
        <Setter Property="local:TextBoxAttached.AutoSelectable" Value="True" />
    </Style>
</Page.Resources>

Select 应用程序中所有文本框的 TextBox 中的所有文本

Select all text in TextBox for all textboxes in app

c#

xaml

windows-10

uwp