如何从文本块的 InLine 事件中设置依赖属性？答案

【问题标题】：How to set a dependency property from InLine event of a textblock?如何从文本块的 InLine 事件中设置依赖属性？
【发布时间】：2015-01-25 02:48:07
【问题描述】：

我正在尝试从 CustomTextBlock 的 MouseEnter 的内联事件中设置依赖属性“WordPad”。但是这个错误结果：

非静态字段、方法或属性“WpfCustomControlLibrary.CustomTextBlock.WordPad.get”需要对象引用

我怎样才能做到这一点？

任何帮助将不胜感激。谢谢。

给定以下类：

 public class CustomTextBlock : TextBlock
{
      public string InLineText
    {
        get { return (string)GetValue(InLineTextProperty); }
        set { SetValue(InLineTextProperty, value); }
    }

     public static readonly DependencyProperty InLineTextProperty =
        DependencyProperty.Register("InLineText", typeof(string), typeof(CustomTextBlock),
            new FrameworkPropertyMetadata(string.Empty,
                FrameworkPropertyMetadataOptions.AffectsMeasure,
                (o, e) =>
                {
                    //PropertyChangedCallback

                    CustomTextBlock tb = (CustomTextBlock)o;
                    string text = (string)e.NewValue;

                    tb.Inlines.Clear();

                    if (String.IsNullOrEmpty(text))
                        return;

                    List<Inline> inlines = new List<Inline>();

                    string[] words = Regex.Split(text, @"(\s+)");

                    Inline inline = null;
                    foreach (string s in words)
                    {
                        Run run = new Run(s);
                        inline = run;
                        inline.MouseEnter += new System.Windows.Input.MouseEventHandler(inline_MouseEnter);
                        inline.MouseLeave += new System.Windows.Input.MouseEventHandler(inline_MouseLeave);
                        tb.Inlines.Add(inline);
                    }
                }));


     public WritingPad WordPad
    {
        get { return (WritingPad)GetValue(WordPadProperty); }
        set { SetValue(WordPadProperty, value); }
    }

     public static readonly DependencyProperty WordPadProperty =
        DependencyProperty.Register("WordPad", typeof(WritingPad), typeof(CustomTextBlock), new UIPropertyMetadata(null));


static void inline_MouseEnter(object sender, System.Windows.Input.MouseEventArgs e)
    {
        Run Sender = sender as Run;
        TextPointer tp0 = Sender.ContentStart;
        TextPointer tp1 = Sender.ContentEnd;

        Rect StartRect = tp0.GetCharacterRect(LogicalDirection.Forward);
        Rect EndRect = tp1.GetCharacterRect(LogicalDirection.Backward);
        StartRect.Union(EndRect);

        WordPad = new WritingPad();   <--**THIS FAILS ????


    }

【问题讨论】：

标签： wpf dependency-properties textblock

【解决方案1】：

将inline_MouseEnter 和inline_MouseLeave 方法设为非静态并将它们附加到您的运行中，如下所示：

inline.MouseEnter += tb.inline_MouseEnter;
inline.MouseLeave += tb.inline_MouseLeave;

更好的办法是让整个 PropertyChangedCallback 非静态，然后像这样编写依赖属性声明：

public static readonly DependencyProperty InLineTextProperty =
    DependencyProperty.Register("InLineText", typeof(string), typeof(CustomTextBlock),
        new FrameworkPropertyMetadata(string.Empty,
            FrameworkPropertyMetadataOptions.AffectsMeasure,
            (o, e) => ((CustomTextBlock)o).InlineTextChanged((string)e.NewValue)));

private void InlineTextChanged(string text)
{
    Inlines.Clear();

    if (!string.IsNullOrEmpty(text))
    {
        foreach (string s in Regex.Split(text, @"(\s+)"))
        {
            var run = new Run(s);
            run.MouseEnter += inline_MouseEnter;
            run.MouseLeave += inline_MouseLeave;
            Inlines.Add(run);
        }
    }
}

【讨论】：

【解决方案2】：

我希望大师可以提供更好的解决方案。

需要注意的是，Run 有一个“Parent”属性，它解析到这个 CustomTextBlock 实例。因此，这似乎可行，

  CustomTextBlock ctb = Sender.Parent as CustomTextBlock;
        ctb.WordPad = new WritingPad
        {
            WordBounds = StartRect,
            WritingPadMode = Enumerations.WritingPadModes.EditingByWord
        };

【讨论】：