咱们在利用到WINFORM窗体工作中，要求RichTextBox 参加行号；
之前有看到大牛们写的，可是太杂乱繁复，而且有效双TextBox举办联动，非常不错，本日咱们实行RichTextBox +Panel相互联动如下效果.
左边灰色为Panel，右侧为RichTextBox 控件
1：预备Panel画布如下代码，当接到文件字符后举办坐标分析，制作行号。
1 private void showLineNo()
2 {
3 //获恰当时坐标信息
4 Point p = this.txtFileView.Location;
5 int crntFirstIndex = this.txtFileView.GetCharIndexFromPosition(p);
6
7 int crntFirstLine = this.txtFileView.GetLineFromCharIndex(crntFirstIndex);
8
9 Point crntFirstPos = this.txtFileView.GetPositionFromCharIndex(crntFirstIndex);
10
11 p.Y += this.txtFileView.Height;
12
13 int crntLastIndex = this.txtFileView.GetCharIndexFromPosition(p);
14
15 int crntLastLine = this.txtFileView.GetLineFromCharIndex(crntLastIndex);
16 Point crntLastPos = this.txtFileView.GetPositionFromCharIndex(crntLastIndex);
17
18 //预备绘图
19 Graphics g = this.panel2.CreateGraphics();
20
21 Font font = new Font(this.txtFileView.Font, this.txtFileView.Font.Style);
22
23 SolidBrush brush = new SolidBrush(Color.Green);
24
25 //绘图开端
26
27 //改造画布
28
29 Rectangle rect = this.panel2.ClientRectangle;
30 brush.Color = this.panel2.BackColor;
31
32 g.FillRectangle(brush, 0, 0, this.panel2.ClientRectangle.Width, this.panel2.ClientRectangle.Height);
33
34 brush.Color = Color.White;//重置画笔颜色
35
36 //制作行号
37
38 int lineSpace = 0;
39
40 if (crntFirstLine != crntLastLine)
41 {
42 lineSpace = (crntLastPos.Y - crntFirstPos.Y) / (crntLastLine - crntFirstLine);
43
44 }
45
46 else
47 {
48 lineSpace = Convert.ToInt32(this.txtFileView.Font.Size);
49
50 }
51 int brushX = this.panel2.ClientRectangle.Width - Convert.ToInt32(font.Size * 3);
52
53 int brushY = crntLastPos.Y + Convert.ToInt32(font.Size * 0.21f);
54 for (int i = crntLastLine; i >= crntFirstLine; i--)
55 {
56
57 g.DrawString((i + 1).ToString(), font, brush, brushX, brushY);
58
59 brushY -= lineSpace;
60 }
61
62 g.Dispose();
63
64 font.Dispose();
65
66 brush.Dispose();
67 }
View Code
2：事端预备（启用）如下事端
控件加载事端
1 private void txtFileView_TextChanged(object sender, EventArgs e)
2 {
3 showLineNo();
4 }
View Code
控件滚动事端（当算出的行数大于本控件长度）
1 private void txtFileView_VScroll(object sender, EventArgs e)
2 {
3 showLineNo();
4 }
View Code
完成后，直接启用运行，Demo案例中的效果就出来，方便各人用于各种应用上.
