如何通过鼠标单击在 RichTextBox 中选择一行? [英] How to select a line in a RichTextBox on a mouse click?

问题描述

我的用户界面中有一个只读 RichTextBox.我想让它当我用鼠标单击一行文本时，它会选择或突出显示整行.只是被点击的那一行.

I have a read-only RichTextBox in my user interface. I want to make it so that when I click on a line of text with the mouse it selects or highlights the entire line. Just that one line that was clicked.

你是怎么做到的?

推荐答案

RichTextBox 拥有您需要的所有方法，您只需要其中的多个.首先需要将鼠标位置映射到字符索引:

RichTextBox has all the methods you need, you just need multiple of them. First you need to map the mouse position to a character index:

Private Sub RichTextBox1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)
    Dim box = DirectCast(sender, RichTextBox)
    Dim index = box.GetCharIndexFromPosition(e.Location)

然后需要将字符索引映射到一行:

Then you need to map the character index to a line:

    Dim line = box.GetLineFromCharIndex(index)

然后你需要找出该行从哪里开始:

Then you need to find out where the line starts:

    Dim lineStart = box.GetFirstCharIndexFromLine(line)

然后你需要找出它在哪里结束，也就是下一行的开始减一:

Then you need to find out where it ends, which is the start of the next line minus one:

    Dim lineEnd = box.GetFirstCharIndexFromLine(line + 1) - 1

然后您需要进行选择:

    box.SelectionStart = lineStart
    box.SelectionLength = lineEnd - lineStart

总结:

Private Sub RichTextBox1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) Handles RichTextBox1.MouseDown
    Dim box = DirectCast(sender, RichTextBox)
    Dim index = box.GetCharIndexFromPosition(e.Location)
    Dim line = box.GetLineFromCharIndex(index)
    Dim lineStart = box.GetFirstCharIndexFromLine(line)
    Dim lineEnd = box.GetFirstCharIndexFromLine(line + 1) - 1
    box.SelectionStart = lineStart
    box.SelectionLength = lineEnd - lineStart
End Sub

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