用到.Net中绘图类，实现折线图的绘制，生成图片，在页面的显示，代码如下：
1 /// <summary>
2 /// 获取数据
3 /// strChartName：图名称；
4 /// yName：纵坐标名称；
5 /// xName：横坐标名称；
6 /// iyMaxValue:纵坐标最大值；
7 /// dyAveValue:纵坐标单位值=（纵坐标最大值/标量30）
8 /// ----100 30 :3
9 /// ----200 30 :1.5；
10 /// xdbColumnName:横坐标绑定显示数据表值的列名；
11 /// ydbColumnName:纵坐标绑定显示数据表值得列名；
12 /// </summary>
13 public void Get_CurveData(string strSql,string strChartName,string yName,string xName,int iyMaxValue, double dyAveValue,string xdbColumnName,string ydbColumnName)
14 {
15 try
16 {
17 DataSet ds = sqlAccess.ReadFromDB(strSql);
18 draw(ds.Tables[0], strChartName, yName, xName, iyMaxValue, dyAveValue, xdbColumnName, ydbColumnName);
19 }
20 catch (Exception exp)
21 {
22 Response.Write(sqlAccess.ExceptionMessage);
23 }
24 }
25
26 public void draw(DataTable dt, string strChartName, string yName, string xName, int iyMaxValue, double dyAveValue, string xdbColumnName, string ydbColumnName)
27 {
28 //取得记录数量
29 int count = dt.Rows.Count;
30 //记算图表宽度
31 int wd = 80 + 20 * (count - 1);
32 //设置最小宽度为800
33 if (wd < 600) wd = 600;
34 //生成Bitmap对像
35 Bitmap img = new Bitmap(wd, 400);
36 //生成绘图对像
37 Graphics g = Graphics.FromImage(img);
38 //定义黑色画笔
39 Pen Bp = new Pen(Color.Black);
40 //定义红色画笔
41 Pen Rp = new Pen(Color.Red);
42 //定义银灰色画笔
43 Pen Sp = new Pen(Color.Silver);
44 //定义蓝色画笔
45 Pen Blp = new Pen(Color.Blue);
46 //定义大标题字体
47 Font Bfont = new Font("Arial", 12, FontStyle.Bold);
48 //定义一般字体
49 Font font = new Font("Arial", 9);
50 //定义大点的字体
51 Font Tfont = new Font("Arial", 9);
52 //定义横坐标间隔，(最佳值是总宽度-留空宽度[左右侧都需要])/(记录数量-1)
53 int xSpace = (wd - 100) / (count - 1);
54 //定义纵坐标间隔,不能随便修改，跟高度和横坐标线的条数有关，最佳值=(绘图的高度-上面留空-下面留空)
55 int ySpace = 30;
56 //纵坐标最大值和间隔值
57 int yMaxValue = iyMaxValue;
58 //绘制底色
59 g.DrawRectangle(new Pen(Color.White, 400), 0, 0, img.Width, img.Height);
60 //定义黑色过渡型笔刷
61 LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Black, Color.Black, 1.2F, true);
62 //定义蓝色过渡型笔刷
63 LinearGradientBrush Bluebrush = new LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Blue, Color.Blue, 1.2F, true);
64 //绘制大标题
65 g.DrawString(strChartName, Bfont, brush, 40, 5);
66 //绘制信息简报
67 //string info = " 曲线图生成时间：" + DateTime.Now.ToString();
68 //g.DrawString(info, Tfont, Bluebrush, 40, 25);
69 //绘制图片边框
70 g.DrawRectangle(Bp, 0, 0, img.Width - 1, img.Height - 1);
71 //绘制竖坐标轴
72 g.DrawLine(Bp, 40, 55, 40, 360);
73 //绘制横坐标轴 x2的60是右侧空出部分
74 g.DrawLine(Bp, 40, 360, 60 + xSpace * (count - 1), 360);
75 //绘制竖坐标标题
76 g.DrawString(yName, Tfont, brush, 5, 40);
77 //绘制横坐标标题
78 g.DrawString(xName, Tfont, brush, 40, 385);
79 //绘制竖坐标线
80 for (int i = 0; i < count; i++)
81 {
82 g.DrawLine(Sp, 40 + xSpace * i, 60, 40 + xSpace * i, 360);
83 }
84 //绘制时间轴坐标标签
85 for (int i = 0; i < count; i++)
86 {
87 //string st = Convert.ToDateTime(dt.Rows[i]["testdate"]).ToString("MM:dd");
88 //string st = "第" + dt.Rows[i]["testdate"].ToString() + "周";
89 string st = dt.Rows[i][xdbColumnName].ToString();
90 g.DrawString(st, font, brush, 30 + xSpace * i, 370);
91 }
92 //绘制横坐标线
93 for (int i = 0; i < 10; i++)
94 {
95 g.DrawLine(Sp, 40, 60 + ySpace * i, 40 + xSpace * (count - 1), 60 + ySpace * i);
96 //横坐标轴的值间隔是最大值除以间隔数
97 int s = yMaxValue - i * (yMaxValue / 10);
98 //绘制发送量轴坐标标签
99 g.DrawString(s.ToString(), font, brush, 10, 60 + ySpace * i);
100 }
101
102 //处理39.6%形式的数据
103 string[] strArr = new string[dt.Rows.Count];
104 for (int i = 0; i < count; i++)
105 {
106 string strValue = dt.Rows[i][ydbColumnName].ToString();
107 if (strValue.Contains("%"))
108 {
109 strArr[i] = strValue.Split(‘%‘)[0];
110 }
111 else
112 {
113 strArr[i] = strValue;
114 }
115 }
116 //200/30
117 //定义纵坐标单位数值=纵坐标最大值/标量最大值
118 double yAveValue = dyAveValue;
119 //定义曲线转折点
120 Point[] p = new Point[count];
121 for (int i = 0; i < count; i++)
122 {
123 p[i].X = 40 + xSpace * i;
124 p[i].Y = 360 - Convert.ToInt32(Convert.ToDouble(strArr[i]) * yAveValue);
125 }
126
127 //绘制折线图
128 //g.DrawLines(Rp, p);
129 //绘制曲线图
130 //g.DrawCurve(Rp, p);
131 //绘制自定义张力的曲线图（0.5F是张力值，默认就是这个值）
132 g.DrawCurve(Rp, p, 0.5F);
133 //g.DrawLines(Rp, p);
134 //当需要在一个图里绘制多条曲线的时候，就多定义个point数组，然后画出来就可以了。
135 for (int i = 0; i < count; i++)
136 {
137 //绘制发送记录点的发送量
138 g.DrawString(strArr[i], font, Bluebrush, p[i].X, p[i].Y - 10);
139 //绘制发送记录点
140 g.DrawRectangle(Rp, p[i].X - 1, p[i].Y - 1, 2, 2);
141 }
142
143 ///*******************画中值线///
144 //for (int i = 0; i < count; i++)
145 //{
146 // p[i].X = 40 + xSpace * i;
147 // p[i].Y = 360 - Convert.ToInt32("50") * yAveValue;
148 //}
149 //for (int i = 0; i < count; i++)
150 //{
151 // //绘制发送记录点的发送量
152 // g.DrawString("", font, Bluebrush, p[i].X, p[i].Y - 10);
153 // //绘制发送记录点
154 // g.DrawRectangle(Rp, p[i].X - 1, p[i].Y - 1, 2, 2);
155 //}
156 //g.DrawLine(Blp, 40, 360 - Convert.ToInt32("50") * yAveValue, 60 + xSpace * (count - 1), 360 - Convert.ToInt32("50") * yAveValue);
157 ///**************************///
158
159 //保存绘制的图片
160 MemoryStream stream = new MemoryStream();
161 img.Save(stream, ImageFormat.Jpeg);
162 //图片输出
163 Response.Clear();
164 Response.ContentType = "image/jpeg";
165 Response.BinaryWrite(stream.ToArray());
166 }
167 }
时间： 2025-01-17 04:56:21