获取/设置RichTextBox的第一条可见线 [英] Get/Set First Visible Line of RichTextBox

问题描述

我有一个 RichTextBox ，其中包含数千行文本.通过执行以下操作，我可以轻松地使用 ScrollToCaret() SET 来显示第一个可见行.

I have a RichTextBox with thousands of lines of text in it. I can easily SET the first visible line by using ScrollToCaret() by doing...

this.SelectionStart = this.Find(this.Lines[lineIndex], RichTextBoxFinds.NoHighlight);
this.ScrollToCaret();

但是我也希望能够 GET 第一行.有什么建议吗?

But I would like to be able to GET the first visible line too. Any suggestions?

推荐答案

以下可能是您需要的:

//get the first visible char index
int firstVisibleChar = richTextBox1.GetCharIndexFromPosition(new Point(0,0));
//get the line index from the char index
int lineIndex = richTextBox1.GetLineFromCharIndex(firstVisibleChar);
//just get the string of the line
string firstVisibleLine = richTextBox1.Lines[lineIndex];

对于说您想要一些与 RichTextBox 的 Width 相对应的行的评论，您可以执行以下操作:

For your comment saying that you want some line accordingly to the Width of the RichTextBox, you can do something like this:

int firstVisibleChar = richTextBox1.GetCharIndexFromPosition(new Point(0,0));
int lastChar = richTextBox1.GetCharIndexFromPosition(new Point(richTextBox1.ClientSize.Width - 1, 1));
string firstVisibleLine = richTextBox1.Text.Substring(firstVisibleChar, lastChar - firstVisibleChar);

这篇关于获取/设置RichTextBox的第一条可见线的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！