C# 控件 RichTextBox 显示行号，并且与Panel相互联动

我们在利用到WINFORM窗体工作中，要求RichTextBox 参加行号；

之前有看到大牛们写的，但是太复杂繁多，而且有效双TextBox举行联动，非常不错，本日我们实行RichTextBox +Panel相互联动如下效果.

左侧灰色为Panel，右侧为RichTextBox 控件

1：准备Panel画布如下代码，当接到文件字符后举行坐标剖析，绘制行号。

1. 1 private void showLineNo()
2. 2 {
3. 3 //获恰当前坐标信息
4. 4 Point p = this.txtFileView.Location;
5. 5 int crntFirstIndex = this.txtFileView.GetCharIndexFromPosition(p);
6. 6
7. 7 int crntFirstLine = this.txtFileView.GetLineFromCharIndex(crntFirstIndex);
8. 8
9. 9 Point crntFirstPos = this.txtFileView.GetPositionFromCharIndex(crntFirstIndex);
10. 10
11. 11 p.Y += this.txtFileView.Height;
12. 12
13. 13 int crntLastIndex = this.txtFileView.GetCharIndexFromPosition(p);
14. 14
15. 15 int crntLastLine = this.txtFileView.GetLineFromCharIndex(crntLastIndex);
16. 16 Point crntLastPos = this.txtFileView.GetPositionFromCharIndex(crntLastIndex);
17. 17
18. 18 //准备绘图
19. 19 Graphics g = this.panel2.CreateGraphics();
20. 20
21. 21 Font font = new Font(this.txtFileView.Font, this.txtFileView.Font.Style);
22. 22
23. 23 SolidBrush brush = new SolidBrush(Color.Green);
24. 24
25. 25 //绘图开始
26. 26
27. 27 //革新画布
28. 28
29. 29 Rectangle rect = this.panel2.ClientRectangle;
30. 30 brush.Color = this.panel2.BackColor;
31. 31
32. 32 g.FillRectangle(brush, 0, 0, this.panel2.ClientRectangle.Width, this.panel2.ClientRectangle.Height);
33. 33
34. 34 brush.Color = Color.White;//重置画笔颜色
35. 35
36. 36 //绘制行号
37. 37
38. 38 int lineSpace = 0;
39. 39
40. 40 if (crntFirstLine != crntLastLine)
41. 41 {
42. 42 lineSpace = (crntLastPos.Y - crntFirstPos.Y) / (crntLastLine - crntFirstLine);
43. 43
44. 44 }
45. 45
46. 46 else
47. 47 {
48. 48 lineSpace = Convert.ToInt32(this.txtFileView.Font.Size);
49. 49
50. 50 }
51. 51 int brushX = this.panel2.ClientRectangle.Width - Convert.ToInt32(font.Size * 3);
52. 52
53. 53 int brushY = crntLastPos.Y + Convert.ToInt32(font.Size * 0.21f);
54. 54 for (int i = crntLastLine; i >= crntFirstLine; i--)
55. 55 {
56. 56
57. 57 g.DrawString((i + 1).ToString(), font, brush, brushX, brushY);
58. 58
59. 59 brushY -= lineSpace;
60. 60 }
61. 61
62. 62 g.Dispose();
63. 63
64. 64 font.Dispose();
65. 65
66. 66 brush.Dispose();
67. 67 }

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2：事故准备（启用）如下事故

控件加载事故

1. 1 private void txtFileView_TextChanged(object sender, EventArgs e)
2. 2 {
3. 3 showLineNo();
4. 4 }

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控件滚动事故（当算出的行数大于本控件长度）

1. 1 private void txtFileView_VScroll(object sender, EventArgs e)
2. 2 {
3. 3 showLineNo();
4. 4 }

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完成后，直接启用运行，Demo事例中的效果就出来，方便各人用于各种应用上.