画一个立体的柱图

画立体柱图应该非常的简单，就是两个截面＋柱体。所以我就不做多的描述了，请直接看代码吧：

 1/**//// <summary>
 2    /// Draw Bar Chart
 3    /// </summary>
 4    /// <param name="g"></param>
 5    /// <param name="value"></param>
 6    private void DrawBarChart(Graphics g, double value)
 7    {
 8        double val = value > 100 ? 100 : value;
 9
10        // Compute size and location
11        Point pt = new Point();
12        int width = 100;
13        int height = 16;
14        int eclipseWidth = 4;
15
16        Rectangle r1 = new Rectangle(pt, new Size(eclipseWidth, height));
17        Rectangle r2 = r1;
18        r2.X += width;
19        Rectangle r3 = r1;
20        r3.X = r1.X + (int)(width * (val / 100.0));
21
22        Rectangle r4 = r1;
23        r4.X = pt.X + (eclipseWidth / 2);
24        r4.Width = width;
25
26        Rectangle r5 = r4;
27        r5.Width = (int)(width * (val / 100.0));
28
29        Pen redPen = new Pen(Color.Red);
30        Pen greenPen = new Pen(Color.Green);
31
32        GraphicsPath gp1 = new GraphicsPath();
33        gp1.AddEllipse(r1);
34        GraphicsPath gp2 = new GraphicsPath();
35        gp2.AddEllipse(r2);
36
37        Region rgn1 = new Region(r4);
38        rgn1.Exclude(gp1);
39        rgn1.Union(gp2);
40
41
42        gp1 = new GraphicsPath();
43        gp1.AddEllipse(r1);
44        gp2 = new GraphicsPath();
45        gp2.AddEllipse(r3);
46
47        Region rgn2 = new Region(r5);
48        rgn2.Exclude(gp1);
49        rgn2.Union(gp2);
50
51        LinearGradientBrush lgb = new LinearGradientBrush(pt, new Point(pt.X, pt.Y + height), Color.Black, Color.Yellow);
52        lgb.SetBlendTriangularShape(0.5f, 1.0f);
53        
54        g.FillRegion(lgb, rgn1);
55
56        lgb = new LinearGradientBrush(pt, new Point(pt.X, pt.Y + height), Color.Navy, Color.Green);
57        if (value > 100)
58        {
59            lgb = new LinearGradientBrush(pt, new Point(pt.X, pt.Y + height), Color.Navy, Color.Red);
60        }
61        lgb.SetBlendTriangularShape(0.5f, 1.0f);
62        g.FillRegion(lgb, rgn2);
63
64
65        PathGradientBrush pb = new PathGradientBrush(gp1);
66        pb.SurroundColors = new Color[] { Color.Gray };
67        pb.CenterColor = pb.CenterColor = Color.LightYellow;
68
69        g.FillEllipse(pb, r1);
70
71        Font f = new Font(FontFamily.GenericSansSerif,9.0f);
72
73        string text = string.Format("{0}%", value);
74        if (value > 100)
75        {
76            text = "过期未完成";
77        }
78        
79        Color fntColor = Color.White;
80        if (val < 50)
81        {
82            fntColor = Color.Purple;
83        }
84        
85        RectangleF textRect = this.ComputeTextRectangle(g, r4, f, text);
86        g.DrawString(text, f, new SolidBrush(fntColor), textRect, StringFormat.GenericTypographic); 
87
88    }

需要把所画的图像由页面展示出来：

 1    protected void Page_Load(object sender, EventArgs e)
 2    {
 3        Response.Clear();
 4        Response.ContentType = "image/jpeg";
 5
 6        string error = Request["error"];
 7        string progress = Request["progress"];
 8
 9        MemoryStream ms = new MemoryStream();
10
11        Bitmap bmp = new Bitmap(110,17);
12        using (Graphics g = Graphics.FromImage(bmp))
13        {
14            g.Clear(Color.White);
15
16            if (string.IsNullOrEmpty(progress))
17            {
18                error = "1";
19            }
20
21            if (!string.IsNullOrEmpty(error))
22            {
23                this.DrawError(g, int.Parse(error));
24            }
25            else
26            {
27                this.DrawBarChart(g, double.Parse(progress));
28            }
29        }
30
31        bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
32    }

效果图如下，里面有比较明显的锯齿，主要是所选取的位图尺寸比较小，如果取大一些再来缩小展现的话，效果应该会好些。