加兩個控件：Panel/RichTextBox
view sourceprint?01 //方法
02
03 private void showLineNo()
04
05 {
06
07 //獲得當前坐標信息
08
09 Point p = this.richTextBox1.Location;
10 int crntFirstIndex = this.richTextBox1.GetCharIndexFromPosition(p);
11
12 int crntFirstLine = this.richTextBox1.GetLineFromCharIndex(crntFirstIndex);
13
14 Point crntFirstPos = this.richTextBox1.GetPositionFromCharIndex(crntFirstIndex);
15
16 //
17 p.Y += this.richTextBox1.Height;
18
19 //
20
21 int crntLastIndex = this.richTextBox1.GetCharIndexFromPosition(p);
22
23 int crntLastLine = this.richTextBox1.GetLineFromCharIndex(crntLastIndex);
24 Point crntLastPos = this.richTextBox1.GetPositionFromCharIndex(crntLastIndex);
25
26 //
27
28 //
29
30 //准備畫圖
31 Graphics g = this.panel1.CreateGraphics();
32
33 Font font = new Font(this.richTextBox1.Font,this.richTextBox1.Font.Style);
34
35 SolidBrush brush = new SolidBrush(Color.Green);
36
37 //
38 //
39
40 //畫圖開始
41
42 //刷新畫布
43
44 Rectangle rect = this.panel1.ClientRectangle;
45 brush.Color = this.panel1.BackColor;
46
47 g.FillRectangle(brush, 0, 0, this.panel1.ClientRectangle.Width,this.panel1.ClientRectangle.Height);
48
49 brush.Color = Color.Green;//重置畫筆顏色
50
51 //
52 //繪制行號
53
54 int lineSpace = 0;
55
56 if (crntFirstLine != crntLastLine)
57
58 {
59 lineSpace = (crntLastPos.Y - crntFirstPos.Y) / (crntLastLine - crntFirstLine);
60
61 }
62
63 else
64
65 {
66 lineSpace = Convert.ToInt32(this.richTextBox1.Font.Size);
67
68 }
69
70 int brushX = this.panel1.ClientRectangle.Width - Convert.ToInt32(font.Size * 3);
71
72 int brushY = crntLastPos.Y+ Convert.ToInt32(font.Size*0.21f);//驚人的算法啊！！
73 for (int i = crntLastLine; i >= crntFirstLine;i-- )
74
75 {
76
77 g.DrawString((i + 1).ToString(), font, brush, brushX, brushY);
78
79 brushY -= lineSpace;
80 }
81
82 g.Dispose();
83
84 font.Dispose();
85
86 brush.Dispose();
87 }
