在 RichTextBox 中设置 Caret/Cursor 位置 - WPF

Question

如何在 WPF 中设置 RichTextBox 中的 caret/cursor 位置？

我用了MSDN CaretPosition中的代码，但是好像不能设置光标？

// 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;

Answer 1

记得设置焦点以便光标出现在 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;

.

除了设置到文档结束外，您还可以使用GetPositionAtOffset设置caretPosbackward / forward和您要移动的位移量：

int displacement = 8;

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

.

例子，你可以把它粘贴到一个空Window的构造函数中来测试：

    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：

(我把window移到中间防止残影)

.

其他补充：

如果你想将 RichTextBox 插入符号向上或向下移动一行，你可以看到 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);

Answer 2

How to set caret/cursor position in RichTextBox in WPF?

假设rtb是你的RichTextBox的名称，与Blocks and Inlines不同，你可以通过以下方式设置文档开头的插入符号：

rtb.CaretPosition = rtb.CaretPosition.DocumentStart;

或最后：

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);

您可以将插入符号设置为开头

rtb.CaretPosition = blk.ContentStart;

或其结尾

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，如果您正在处理包含从右到左和从左到右文本的复杂段落，您可能需要考虑

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

另请注意 TextPointer 中实现的不同方法，您可以使用它们到达 document/Blocks/Inlines 的不同部分：

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

有关更多方法和更多信息，请参阅 link。

最后，您可能想使用 BringIntoView 在块或内联中实现的方法：

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

并设置键盘焦点，以查看插入符的 blinking：

Keyboard.Focus(rtb);

在 RichTextBox 中设置 Caret/Cursor 位置 - WPF

Set Caret/Cursor Position in RichTextBox - WPF

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