有没有什么方法可以选择WPF文本块？-Java 学习之路

191

我想在Witty中显示文本，这是一个开源的Twitter客户端，可以选择 . 它目前使用自定义文本块显示 . 我需要使用TextBlock，因为我'm working with the textblock'内联显示和格式化@username和链接作为超链接 . 经常请求是能够复制粘贴文本 . 为了做到这一点，我需要使TextBlock可选 .

我试图通过使用只读TextBox来显示文本，使其看起来像文本块，但这在我的情况下不起作用，因为TextBox没有内联 . 换句话说，我不能单独设置或格式化TextBox中的文本，就像我可以使用TextBlock一样 .

有任何想法吗？

14 回答

<TextBox Background="Transparent"
         BorderThickness="0"
         Text="{Binding Text, Mode=OneWay}"
         IsReadOnly="True"
         TextWrapping="Wrap" />

回复于 2024-04-25T23:46:15+08:00

这里的所有答案都只是使用 TextBox 或尝试手动实现文本选择，这会导致性能不佳或非本机行为（ TextBox 中闪烁插入符号，手动实现中没有键盘支持等）

经过几个小时的挖掘并阅读WPF source code，我发现了一种为 TextBlock 控件（或实际上任何其他控件）启用本机WPF文本选择的方法 . 文本选择的大多数功能都在 System.Windows.Documents.TextEditor 系统类中实现 .

要为控件启用文本选择，您需要做两件事：

调用 TextEditor.RegisterCommandHandlers() 一次以注册类事件处理程序
为您的类的每个实例创建 TextEditor 的实例，并将 System.Windows.Documents.ITextContainer 的基础实例传递给它

's also a requirement that your control' s Focusable 属性设置为 True .

就是这个！听起来很简单，但不幸的是 TextEditor 类被标记为内部 . 所以我不得不在它周围写一个反射包装器：

class TextEditorWrapper
{
    private static readonly Type TextEditorType = Type.GetType("System.Windows.Documents.TextEditor, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35");
    private static readonly PropertyInfo IsReadOnlyProp = TextEditorType.GetProperty("IsReadOnly", BindingFlags.Instance | BindingFlags.NonPublic);
    private static readonly PropertyInfo TextViewProp = TextEditorType.GetProperty("TextView", BindingFlags.Instance | BindingFlags.NonPublic);
    private static readonly MethodInfo RegisterMethod = TextEditorType.GetMethod("RegisterCommandHandlers", 
        BindingFlags.Static | BindingFlags.NonPublic, null, new[] { typeof(Type), typeof(bool), typeof(bool), typeof(bool) }, null);

    private static readonly Type TextContainerType = Type.GetType("System.Windows.Documents.ITextContainer, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35");
    private static readonly PropertyInfo TextContainerTextViewProp = TextContainerType.GetProperty("TextView");

    private static readonly PropertyInfo TextContainerProp = typeof(TextBlock).GetProperty("TextContainer", BindingFlags.Instance | BindingFlags.NonPublic);

    public static void RegisterCommandHandlers(Type controlType, bool acceptsRichContent, bool readOnly, bool registerEventListeners)
    {
        RegisterMethod.Invoke(null, new object[] { controlType, acceptsRichContent, readOnly, registerEventListeners });
    }

    public static TextEditorWrapper CreateFor(TextBlock tb)
    {
        var textContainer = TextContainerProp.GetValue(tb);

        var editor = new TextEditorWrapper(textContainer, tb, false);
        IsReadOnlyProp.SetValue(editor._editor, true);
        TextViewProp.SetValue(editor._editor, TextContainerTextViewProp.GetValue(textContainer));

        return editor;
    }

    private readonly object _editor;

    public TextEditorWrapper(object textContainer, FrameworkElement uiScope, bool isUndoEnabled)
    {
        _editor = Activator.CreateInstance(TextEditorType, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.CreateInstance, 
            null, new[] { textContainer, uiScope, isUndoEnabled }, null);
    }
}

我还创建了一个 SelectableTextBlock 派生自 TextBlock ，采取上述步骤：

public class SelectableTextBlock : TextBlock
{
    static SelectableTextBlock()
    {
        FocusableProperty.OverrideMetadata(typeof(SelectableTextBlock), new FrameworkPropertyMetadata(true));
        TextEditorWrapper.RegisterCommandHandlers(typeof(SelectableTextBlock), true, true, true);

        // remove the focus rectangle around the control
        FocusVisualStyleProperty.OverrideMetadata(typeof(SelectableTextBlock), new FrameworkPropertyMetadata((object)null));
    }

    private readonly TextEditorWrapper _editor;

    public SelectableTextBlock()
    {
        _editor = TextEditorWrapper.CreateFor(this);
    }
}

另一种选择是为 TextBlock 创建附加属性，以便根据需要启用文本选择 . 在这种情况下，要再次禁用选择，需要使用与此代码等效的反射来分离 TextEditor ：

_editor.TextContainer.TextView = null;
_editor.OnDetach();
_editor = null;

回复于 2024-04-25T23:46:15+08:00

我一直无法找到真正回答这个问题的任何例子 . 所有答案都使用了Textbox或RichTextbox . 我需要一个允许我使用TextBlock的解决方案，这就是我创建的解决方案 .

我相信正确的方法是扩展TextBlock类 . 这是我用来扩展TextBlock类的代码，允许我选择文本并将其复制到剪贴板 . “sdo”是我在WPF中使用的命名空间引用 .

WPF Using Extended Class:

xmlns:sdo="clr-namespace:iFaceCaseMain"

<sdo:TextBlockMoo x:Name="txtResults" Background="Black" Margin="5,5,5,5" 
      Foreground="GreenYellow" FontSize="14" FontFamily="Courier New"></TextBlockMoo>

Code Behind for Extended Class:

public partial class TextBlockMoo : TextBlock 
{
    TextPointer StartSelectPosition;
    TextPointer EndSelectPosition;
    public String SelectedText = "";

    public delegate void TextSelectedHandler(string SelectedText);
    public event TextSelectedHandler TextSelected;

    protected override void OnMouseDown(MouseButtonEventArgs e)
    {
        base.OnMouseDown(e);
        Point mouseDownPoint = e.GetPosition(this);
        StartSelectPosition = this.GetPositionFromPoint(mouseDownPoint, true);            
    }

    protected override void OnMouseUp(MouseButtonEventArgs e)
    {
        base.OnMouseUp(e);
        Point mouseUpPoint = e.GetPosition(this);
        EndSelectPosition = this.GetPositionFromPoint(mouseUpPoint, true);

        TextRange otr = new TextRange(this.ContentStart, this.ContentEnd);
        otr.ApplyPropertyValue(TextElement.ForegroundProperty, new SolidColorBrush(Colors.GreenYellow));

        TextRange ntr = new TextRange(StartSelectPosition, EndSelectPosition);
        ntr.ApplyPropertyValue(TextElement.ForegroundProperty, new SolidColorBrush(Colors.White));

        SelectedText = ntr.Text;
        if (!(TextSelected == null))
        {
            TextSelected(SelectedText);
        }
    }
}

Example Window Code:

public ucExample(IInstanceHost host, ref String WindowTitle, String ApplicationID, String Parameters)
    {
        InitializeComponent();
        /*Used to add selected text to clipboard*/
        this.txtResults.TextSelected += txtResults_TextSelected;
    }

    void txtResults_TextSelected(string SelectedText)
    {
        Clipboard.SetText(SelectedText);
    }

回复于 2024-04-25T23:46:15+08:00

19

为TextBlock创建ControlTemplate并将TextBox放在readonly属性集中 . 或者只使用TextBox并使其只读，然后您可以更改TextBox.Style以使其看起来像TextBlock .

回复于 2024-04-25T23:46:15+08:00

将此样式应用于TextBox，就是这样（灵感来自this article）：

<Style x:Key="SelectableTextBlockLikeStyle" TargetType="TextBox" BasedOn="{StaticResource {x:Type TextBox}}">
    <Setter Property="IsReadOnly" Value="True"/>
    <Setter Property="IsTabStop" Value="False"/>
    <Setter Property="BorderThickness" Value="0"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Padding" Value="-2,0,0,0"/>
    <!-- The Padding -2,0,0,0 is required because the TextBox
        seems to have an inherent "Padding" of about 2 pixels.
        Without the Padding property,
        the text seems to be 2 pixels to the left
        compared to a TextBlock
    -->
    <Style.Triggers>
        <MultiTrigger>
            <MultiTrigger.Conditions>
                <Condition Property="IsMouseOver" Value="False" />
                <Condition Property="IsFocused" Value="False" />
            </MultiTrigger.Conditions>
            <Setter Property="Template">
                <Setter.Value>
                <ControlTemplate TargetType="{x:Type TextBox}">
                    <TextBlock Text="{TemplateBinding Text}" 
                             FontSize="{TemplateBinding FontSize}"
                             FontStyle="{TemplateBinding FontStyle}"
                             FontFamily="{TemplateBinding FontFamily}"
                             FontWeight="{TemplateBinding FontWeight}"
                             TextWrapping="{TemplateBinding TextWrapping}"
                             Foreground="{DynamicResource NormalText}"
                             Padding="0,0,0,0"
                                       />
                </ControlTemplate>
                </Setter.Value>
            </Setter>
        </MultiTrigger>
    </Style.Triggers>
</Style>

回复于 2024-04-25T23:46:15+08:00

1

我不确定你是否可以选择TextBlock，但另一种选择是使用RichTextBox - 它就像你建议的TextBox，但支持你想要的格式 .

回复于 2024-04-25T23:46:15+08:00
2

根据Windows Dev Center：

TextBlock.IsTextSelectionEnabled属性[已针对Windows 10上的UWP应用程序进行了更新 . 对于Windows 8.x文章，请参阅存档]获取或设置一个值，该值指示是否在TextBlock中启用文本选择，通过用户操作或调用选择相关API .

回复于 2024-04-25T23:46:15+08:00

TextBlock没有模板 . 因此，为了实现这一点，我们需要使用一个TextBox，其样式被更改为表现为textBlock .

<Style x:Key="TextBlockUsingTextBoxStyle" BasedOn="{x:Null}" TargetType="{x:Type TextBox}">
    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="BorderBrush" Value="{StaticResource TextBoxBorder}"/>
    <Setter Property="BorderThickness" Value="0"/>
    <Setter Property="Padding" Value="1"/>
    <Setter Property="AllowDrop" Value="true"/>
    <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
    <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
    <Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type TextBox}">
                <TextBox BorderThickness="{TemplateBinding BorderThickness}" IsReadOnly="True" Text="{TemplateBinding Text}" Background="{x:Null}" BorderBrush="{x:Null}" />
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

回复于 2024-04-25T23:46:15+08:00

195

有一个替代解决方案可能适用于此_1358223中所包含的RichTextBox - 当用户将鼠标悬停在控件上时，它使用触发器来交换控件模板 - 应该有助于提高性能

回复于 2024-04-25T23:46:15+08:00
-1

虽然问题确实说'可选'但我认为有意的结果是将文本放到剪贴板中 . 通过添加上下文菜单和名为copy的菜单项可以轻松，优雅地实现这一点，该菜单项将Textblock Text属性值放入剪贴板 . 无论如何只是一个想法 .

回复于 2024-04-25T23:46:15+08:00

new TextBox
{
   Text = text,
   TextAlignment = TextAlignment.Center,
   TextWrapping = TextWrapping.Wrap,
   IsReadOnly = true,
   Background = Brushes.Transparent,
   BorderThickness = new Thickness()
         {
             Top = 0,
             Bottom = 0,
             Left = 0,
             Right = 0
         }
};

回复于 2024-04-25T23:46:15+08:00

20
我在我的开源控件库中实现了SelectableTextBlock . 你可以像这样使用它：
```
<jc:SelectableTextBlock Text="Some text" />
```
回复于 2024-04-25T23:46:15+08:00

public MainPage()
{
    this.InitializeComponent();
    ...
    ...
    ...
    //Make Start result text copiable
    TextBlockStatusStart.IsTextSelectionEnabled = true;
}

回复于 2024-04-25T23:46:15+08:00

Really nice and easy solution, exactly what I wanted !

我带了一些小修改

public class TextBlockMoo : TextBlock 
{
    public String SelectedText = "";

    public delegate void TextSelectedHandler(string SelectedText);
    public event TextSelectedHandler OnTextSelected;
    protected void RaiseEvent()
    {
        if (OnTextSelected != null){OnTextSelected(SelectedText);}
    }

    TextPointer StartSelectPosition;
    TextPointer EndSelectPosition;
    Brush _saveForeGroundBrush;
    Brush _saveBackGroundBrush;

    TextRange _ntr = null;

    protected override void OnMouseDown(MouseButtonEventArgs e)
    {
        base.OnMouseDown(e);

        if (_ntr!=null) {
            _ntr.ApplyPropertyValue(TextElement.ForegroundProperty, _saveForeGroundBrush);
            _ntr.ApplyPropertyValue(TextElement.BackgroundProperty, _saveBackGroundBrush);
        }

        Point mouseDownPoint = e.GetPosition(this);
        StartSelectPosition = this.GetPositionFromPoint(mouseDownPoint, true);            
    }

    protected override void OnMouseUp(MouseButtonEventArgs e)
    {
        base.OnMouseUp(e);
        Point mouseUpPoint = e.GetPosition(this);
        EndSelectPosition = this.GetPositionFromPoint(mouseUpPoint, true);

        _ntr = new TextRange(StartSelectPosition, EndSelectPosition);

        // keep saved
        _saveForeGroundBrush = (Brush)_ntr.GetPropertyValue(TextElement.ForegroundProperty);
        _saveBackGroundBrush = (Brush)_ntr.GetPropertyValue(TextElement.BackgroundProperty);
        // change style
        _ntr.ApplyPropertyValue(TextElement.BackgroundProperty, new SolidColorBrush(Colors.Yellow));
        _ntr.ApplyPropertyValue(TextElement.ForegroundProperty, new SolidColorBrush(Colors.DarkBlue));

        SelectedText = _ntr.Text;
    }
}

回复于 2024-04-25T23:46:15+08:00

有没有什么方法可以选择WPF文本块？

14 回答

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