如何允许TextBlock的文本是可选的?
我试图让它通过显示文本使用只读文本框样式看起来像一个文本块,但这不会在我的情况下工作,因为一个文本框没有内联。换句话说,如何使它具有可选性?
如何允许TextBlock的文本是可选的?
我试图让它通过显示文本使用只读文本框样式看起来像一个文本块,但这不会在我的情况下工作,因为一个文本框没有内联。换句话说,如何使它具有可选性?
当前回答
所有的答案在这里只是使用一个文本框或试图实现文本选择手动,这导致性能差或非本机行为(闪烁插入文本框,手动实现不支持键盘等)。
经过几个小时的挖掘和阅读WPF源代码,我反而发现了一种启用本地WPF文本选择TextBlock控件(或真正的任何其他控件)的方法。大多数关于文本选择的功能是在system . windows . documents . texteditor系统类中实现的。
要启用控件的文本选择,您需要做两件事:
调用一次texteitor . registercommandhandlers()来注册类 事件处理程序 为类的每个实例创建一个TextEditor实例,并将System.Windows.Documents.ITextContainer的底层实例传递给它
还有一个要求是控件的Focusable属性设置为True。
就是它了!听起来很简单,但不幸的是,TextEditor类被标记为内部。所以我必须在它周围写一个反射包装:
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);
}
}
我还创建了一个从TextBlock派生的SelectableTextBlock,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创建一个附加属性,以便在需要时启用文本选择。在这种情况下,要再次禁用选择,需要通过使用相当于下面代码的反射来分离TextEditor:
_editor.TextContainer.TextView = null;
_editor.OnDetach();
_editor = null;
其他回答
为torvin的代码添加了Selection & SelectionChanged事件
public class SelectableTextBlock : TextBlock
{
static readonly Type TextEditorType
= Type.GetType("System.Windows.Documents.TextEditor, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35");
static readonly PropertyInfo IsReadOnlyProp
= TextEditorType.GetProperty("IsReadOnly", BindingFlags.Instance | BindingFlags.NonPublic);
static readonly PropertyInfo TextViewProp
= TextEditorType.GetProperty("TextView", BindingFlags.Instance | BindingFlags.NonPublic);
static readonly MethodInfo RegisterMethod
= TextEditorType.GetMethod("RegisterCommandHandlers",
BindingFlags.Static | BindingFlags.NonPublic, null, new[] { typeof(Type), typeof(bool), typeof(bool), typeof(bool) }, null);
static readonly Type TextContainerType
= Type.GetType("System.Windows.Documents.ITextContainer, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35");
static readonly PropertyInfo TextContainerTextViewProp
= TextContainerType.GetProperty("TextView");
static readonly PropertyInfo TextContainerTextSelectionProp
= TextContainerType.GetProperty("TextSelection");
static readonly PropertyInfo TextContainerProp = typeof(TextBlock).GetProperty("TextContainer", BindingFlags.Instance | BindingFlags.NonPublic);
static void RegisterCommandHandlers(Type controlType, bool acceptsRichContent, bool readOnly, bool registerEventListeners)
{
RegisterMethod.Invoke(null, new object[] { controlType, acceptsRichContent, readOnly, registerEventListeners });
}
static SelectableTextBlock()
{
FocusableProperty.OverrideMetadata(typeof(SelectableTextBlock), new FrameworkPropertyMetadata(true));
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;
object? textContainer;
object? editor;
public TextSelection TextSelection { get; private set; }
public SelectableTextBlock()
{
textContainer = TextContainerProp.GetValue(this);
editor = Activator.CreateInstance(TextEditorType, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.CreateInstance,
null, new[] { textContainer, this, false }, null);
IsReadOnlyProp.SetValue(editor, true);
TextViewProp.SetValue(editor, TextContainerTextViewProp.GetValue(textContainer));
TextSelection = (TextSelection)TextContainerTextSelectionProp.GetValue(textContainer);
TextSelection.Changed += (s, e) => OnSelectionChanged?.Invoke(this, e);
}
public event EventHandler OnSelectionChanged;
}
我不确定你是否可以使一个TextBlock可选,但另一个选择是使用RichTextBox -它就像你建议的TextBox,但支持你想要的格式。
我已经实现了SelectableTextBlock在我的开源控件库。你可以这样使用它:
<jc:SelectableTextBlock Text="Some text" />
有一个替代的解决方案,可能适用于这篇博客文章中提到的RichTextBox -它使用一个触发器来交换控件模板,当使用悬停在控件上时-应该有助于性能
Really nice and easy solution, exactly what I wanted !
我带来了一些小改动
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;
}
}