C # Write richTextBox with row number

Add two controls: Panel/RichTextBox

 

View sourceprint? 01 // Method

02

03 private void showLineNo ()

04

05 {

06

07 // obtain the current coordinate information

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 // prepare for drawing

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 // start drawing

41

42 // refresh the canvas

43

44 Rectangle rect = this. panel1.ClientRectangle;

45 brush. Color = this. panel1.BackColor;

46

47g. FillRectangle (brush, 0, 0, this. panel1.ClientRectangle. Width, this. panel1.ClientRectangle. Height );

48

49 brush. Color = Color. Green; // reset the paint Color

50

51 //

52 // draw the row number

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); // amazing algorithm !!

73 for (int I = crntLastLine; I> = crntFirstLine; I --)

74

75 {

76

77g. DrawString (I + 1). ToString (), font, brush, brushX, brushY );

78

79 brushY-= lineSpace;

80}

81

82g. Dispose ();

83

84 font. Dispose ();

85

86 brush. Dispose ();

87}