C# 控件 RichTextBox 显示行号，并且与Panel相互联动

我们在使用到winform窗体工作中，要求richtextbox 加入行号；

之前有看到大牛们写的，但是太复杂繁多，而且有用双textbox进行联动，非常不错，今天我们尝试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，当接到文件字符后进行坐标解析，绘制行号。

 1 private void showlineno()
 2         {
 3             //获得当前坐标信息
 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             //准备画图
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             //画图开始
26 
27             //刷新画布
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             //绘制行号
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         }

 

2：事件准备（启用）如下事件

控件加载事件

1 private void txtfileview_textchanged(object sender, eventargs e)
2         {
3             showlineno();
4         }

控件滚动事件（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         }

完成后，直接启用运行，demo事例中的效果就出来，方便大家用于各种应用上.