带行号的RichTextBox（C#）

 editorControl是一个userControl，其包含两个控件：左侧是一个用来显示行号的RichTextBox（使用label等均可），右侧是一个继承自RichTextBox的component--editorGrid1。

 

(1) 添加事件

        editorGrid1.TextChanged += new EventHandler(editorGrid1_TextChanged);
        editorGrid1.VScroll += new EventHandler(editorGrid1_VScroll);

 

        void editorGrid1_VScroll(object sender, EventArgs e)
        {
            int p = editorGrid1.GetPositionFromCharIndex(0).Y % (editorGrid1.Font.Height + 1);
            richTextBox1.Location = new Point(0, p);
            DrewLineNumber();
        }

 

        private void editorGrid1_TextChanged(object sender, EventArgs e)
        {
            if ( fchange )
            {
                Regex r = new Regex(@"/*");
               
                if( ! r.IsMatch(Parent.Text))
                {
                    Parent.Text += " *";
                }
            }

            DrewLineNumber();
        }

 

(2)更新行号的主函数

        private void DrewLineNumber()
        {
            Point pos = new Point(0, 0);
            int firstIndex = editorGrid1.GetCharIndexFromPosition(pos);
            int firstLine = editorGrid1.GetLineFromCharIndex(firstIndex);

            pos.X = editorGrid1.ClientRectangle.Width;
            pos.Y = editorGrid1.ClientRectangle.Height;

            int endIndex = editorGrid1.GetCharIndexFromPosition(pos);
            int endLine = editorGrid1.GetLineFromCharIndex(endIndex);

            richTextBox1.Text = "";

            for (int i = firstLine; i <= endLine +1 ; i++)
            {
                 richTextBox1.Text += i + 1 + "/n";
            }
        }