在WPF中设置RichTextBox的插入符/光标位置

Question

如何在WPF的RichTextBox中设置插入符/光标位置？

我使用MSDN CaretPosition中的代码，但似乎无法设置光标？

// Create a new FlowDocument, and add 3 paragraphs.
FlowDocument flowDoc = new FlowDocument();
flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 1"))); 
flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 2"))); 
flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 3")));
// Set the FlowDocument to be the content for a new RichTextBox.
RichTextBox rtb = new RichTextBox(flowDoc);

// Get the current caret position.
TextPointer caretPos = rtb.CaretPosition;

// Set the TextPointer to the end of the current document.
caretPos = caretPos.DocumentEnd;

// Specify the new caret position at the end of the current document.
rtb.CaretPosition = caretPos;

- yu yang Jian

Answer 1

如何在WPF中设置RichTextBox中的插入符/光标位置？

假设rtb是您的RichTextBox的名称，且具有不同的Blocks和Inlines，您可以通过以下方式将Caret设置为文档开头：

rtb.CaretPosition = rtb.CaretPosition.DocumentStart;

或者在它的结尾处：

rtb.CaretPosition = rtb.CaretPosition.DocumentEnd;

另一方面，假设您有一个特定的段落或块，例如：

Block blk = rtb.Document.Blocks.ElementAt(1);

您可以将插入符设置为其开头。

rtb.CaretPosition = blk.ContentStart;

或它的结束

rtb.CaretPosition = blk.ContentEnd;

或者如果您有特定的内联，例如

Run r = ((Paragraph)rtb.Document.Blocks.ElementAt(0)).Inlines.ElementAt(1) as Run;

您也可以使用。

rtb.CaretPosition = r.ContentStart;
rtb.CaretPosition = r.ContentEnd;

当然，如果您正在处理既包含从右到左又包含从左到右文字的复杂段落时，您可能需要考虑

rtb.CaretPosition = blk.ElementStart;
rtb.CaretPosition = blk.ElementEnd;

还要注意在TextPointer中实现的不同方法，您可以使用这些方法来访问文档/块/内联的不同部分：

rtb.CaretPosition = rtb.CaretPosition.GetLineStartPosition(0);
rtb.CaretPosition = rtb.CaretPosition.GetPositionAtOffset(2);

请查看链接获取更多方法和更多信息。

最后，您可能想要使用在块或内联中实现的BringIntoView方法：

blk.BringIntoView();
r.BringIntoView();

并设置键盘焦点，以查看插入符号的闪烁：

Keyboard.Focus(rtb);

- rmojab63

Answer 2

请记得设置焦点，这样光标才会出现在 RichTextBox 中：

// Create a new FlowDocument, and add 3 paragraphs.
FlowDocument flowDoc = new FlowDocument();
flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 1"))); 
flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 2"))); 
flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 3")));
// Set the FlowDocument to be the content for a new RichTextBox.
RichTextBox rtb = new RichTextBox(flowDoc);

//****SET FOCUS****
rtb.Focus();

// Get the current caret position.
TextPointer caretPos = rtb.CaretPosition;
// Set the TextPointer to the end of the current document.
caretPos = caretPos.DocumentEnd;
// Specify the new caret position at the end of the current document.
rtb.CaretPosition = caretPos;

除了将设置移动到文档结尾外，您还可以使用GetPositionAtOffset来设置caretPos的向前或向后以及您想要移动的位移量：

int displacement = 8;

// Set the TextPointer 8 displacement backward.
caretPos = caretPos.GetPositionAtOffset(displacement, LogicalDirection.Backward);

例如，您可以将其粘贴到空窗口的构造器中进行测试：

    public RichTbxFlowDocumentTest()
    {
        InitializeComponent();

        // Create a new FlowDocument, and add 3 paragraphs.
        FlowDocument flowDoc = new FlowDocument();
        flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 1")));
        flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 2")));
        flowDoc.Blocks.Add(new Paragraph(new Run("Paragraph 3")));
        // Set the FlowDocument to be the content for a new RichTextBox.
        RichTextBox rtb = new RichTextBox(flowDoc);

        //Add RichTextBox and Button with setting cursor method to a new StackPanel
        StackPanel s = new StackPanel();
        Button button = new Button() { Content = "Set Cursor Pos" };
        button.Click += (sender, e) =>
        {
            //SET FOCUS
            rtb.Focus();

            // Get the current caret position.
            TextPointer caretPos = rtb.CaretPosition;

            //Set amount of displacement
            int displacement = 6;

            // Set the TextPointer 6 displacement backward
            caretPos = caretPos.GetPositionAtOffset(displacement, LogicalDirection.Backward);

            // Specify the new caret position to RichTextBox
            rtb.CaretPosition = caretPos;
        };
        s.Children.Add(button);
        s.Children.Add(rtb);
        this.Content = s;
    }
}

结果:

(我将窗口移到中间，以防止残影)

.

其他补充:

如果要将RichTextBox插入符上下移动一行，请参见https://social.msdn.microsoft.com/Forums/vstudio/en-US/8c34e7b1-91ed-4b11-979d-d18b28a71f6f/how-do-you-move-richtextbox-caret-up-or-down-one-line?forum=wpf

myRichTextBox.Focus();
EditingCommands.MoveUpByLine.Execute(null, myRichTextBox);

- yu yang Jian