asp,net中画图

public class ChartUtil
  {
   public ChartUtil()
   {
   }
   public static Color GetChartItemColor(int itemIndex)
   {
    Color selectedColor;
    switch(itemIndex)
    {
     case 0:
      selectedColor = Color.Blue;
      break;
     case 1:
      selectedColor = Color.Red;
      break;
     case 2:
      selectedColor = Color.Yellow;
      break;
     case 3:
      selectedColor = Color.Purple;
      break;
     default:
      selectedColor = Color.Green;
      break;
    }
    return selectedColor;
   }
  }
  public void Render(int width, int height)
  {
   //string title, string subTitle,
   const int SIDE_LENGTH = 400;
   const int PIE_DIAMETER = 200;
   DataTable dt=new Class.Function().GraphData();
  
   //通过输入参数，取得饼图中的总基数
   float sumData = 0;
//   foreach(DataRow dr in dt.Rows)
//   {
//    sumData += Convert.ToSingle(dr[1]);
//   }
   for(int i=0;i<dt.Rows.Count;i++)
   {
    sumData+=Convert.ToSingle(dt.Rows[i][1].ToString());
   }
   //产生一个image对象，并由此产生一个Graphics对象
   Bitmap bm = new Bitmap(width,height);
   Graphics g = Graphics.FromImage(bm);
   //设置对象g的属性
   g.ScaleTransform((Convert.ToSingle(width))/SIDE_LENGTH,(Convert.ToSingle(height))/SIDE_LENGTH);
   g.SmoothingMode = SmoothingMode.Default;
   g.TextRenderingHint = TextRenderingHint.AntiAlias;
  
   //画布和边的设定
   g.Clear(Color.White);
   //g.DrawRectangle(Pens.Black,0,0,SIDE_LENGTH-1,SIDE_LENGTH-1);

   for(int j=0;j<dt.Rows.Count;j++)
   {
    int s=int.Parse(dt.Rows[j][1].ToString());
    g.DrawString(dt.Rows[j][0].ToString(),new Font("Tahoma",14),Brushes.Black,new PointF(5,j*20));
    g.FillRectangle(new SolidBrush(ChartUtil.GetChartItemColor(j)),50,j*20+10,s+5,20);//j*35)+15
    g.DrawRectangle(Pens.Black,50,j*20+10,s+5,20);
    
   }

   //画饼图标题
   //g.DrawString(title,new Font("Tahoma",24),Brushes.Black,new PointF(5,5));
   //画饼图的图例
   //g.DrawString(subTitle,new Font("Tahoma",14),Brushes.Black,new PointF(7,35));
   //画饼图
//   float curAngle = 0;
//   float totalAngle = 0;
//   for(int i=0;i<dt.Rows.Count;i++)
//   {
//    curAngle = Convert.ToSingle(dt.Rows[i][1]) / sumData * 360;
//  
//    g.FillPie(new SolidBrush(ChartUtil.GetChartItemColor(i)),100,65,PIE_DIAMETER,PIE_DIAMETER,totalAngle,curAngle);
//    g.DrawPie(Pens.Black,100,65,PIE_DIAMETER,PIE_DIAMETER,totalAngle,curAngle);
//    totalAngle += curAngle;
//   }
//   //画图例框及其文字
//   g.DrawRectangle(Pens.Black,200,300,199,99);
//   g.DrawString("图例",new Font("Tahoma",12,FontStyle.Bold),Brushes.Black,new PointF(200,300));
//  
   //画图例各项
   PointF boxOrigin = new PointF(210,330);
   PointF textOrigin = new PointF(235,326);
   float percent = 0;
   for(int i=0;i<dt.Rows.Count;i++)
   {
    g.FillRectangle(new SolidBrush(ChartUtil.GetChartItemColor(i)),boxOrigin.X,boxOrigin.Y,20,10);
    g.DrawRectangle(Pens.Black,boxOrigin.X,boxOrigin.Y,20,10);
    percent = Convert.ToSingle(dt.Rows[i][1]) / sumData * 100;
    g.DrawString(dt.Rows[i][0].ToString()  + " (" + percent.ToString("0") + "%)",new Font("Tahoma",10),Brushes.Black,textOrigin);
    boxOrigin.Y += 15;
    textOrigin.Y += 15;
   }
//   //通过Response.OutputStream，将图形的内容发送到浏览器
   bm.Save(Response.OutputStream, ImageFormat.Gif);
   //回收资源
   bm.Dispose();
   g.Dispose();
  }
  public void Render2(int width, int height)
  {
   const int SIDE_LENGTH = 400;
   const int CHART_TOP = 75;
   const int CHART_HEIGHT = 200;
   const int CHART_LEFT = 50;
   const int CHART_WIDTH = 300;
   DataTable dt=new Class.Function().GraphData();
  
   //计算最高的点
   float highPoint = 0;
   foreach(DataRow dr in dt.Rows)
   {
    if(highPoint<Convert.ToSingle(dr[1]))
    {
     highPoint = Convert.ToSingle(dr[1]);
    }
   }
   //建立一个Graphics对象实例
   Bitmap bm = new Bitmap(width,height);
   Graphics g = Graphics.FromImage(bm);
   //设置条图图形和文字属性
   g.ScaleTransform((Convert.ToSingle(width))/SIDE_LENGTH,(Convert.ToSingle(height))/SIDE_LENGTH);
   g.SmoothingMode = SmoothingMode.Default;
   g.TextRenderingHint = TextRenderingHint.AntiAlias;
  
   //设定画布和边
   g.Clear(Color.White);
   g.DrawRectangle(Pens.Black,0,0,SIDE_LENGTH-1,SIDE_LENGTH-1);
   //画大标题
   //g.DrawString(title,new Font("Tahoma",24),Brushes.Black,new PointF(5,5));
   //画小标题
  //g.DrawString(subTitle,new Font("Tahoma",14),Brushes.Black,new PointF(7,35));
   //画条形图
   float barWidth = CHART_WIDTH / (dt.Rows.Count * 2);
   PointF barOrigin = new PointF(CHART_LEFT + (barWidth / 2),0);
   float barHeight = dt.Rows.Count;
   for(int i=0;i<dt.Rows.Count;i++)
   {
    barHeight = Convert.ToSingle(dt.Rows[i][1]) * 200 / highPoint;
    barOrigin.Y = CHART_TOP + CHART_HEIGHT - barHeight;
    g.FillRectangle(new SolidBrush(ChartUtil.GetChartItemColor(i)),barOrigin.X,barOrigin.Y,barWidth,barHeight);
    barOrigin.X = barOrigin.X + (barWidth * 2);
   }
   //设置边
   g.DrawLine(new Pen(Color.Black,2),new Point(CHART_LEFT,CHART_TOP),new Point(CHART_LEFT,CHART_TOP + CHART_HEIGHT));
   g.DrawLine(new Pen(Color.Black,2),new Point(CHART_LEFT,CHART_TOP + CHART_HEIGHT),new Point(CHART_LEFT + CHART_WIDTH,CHART_TOP + CHART_HEIGHT));
   //画图例框和文字
   g.DrawRectangle(new Pen(Color.Black,1),200,300,199,99);
   g.DrawString("Legend",new Font("Tahoma",12,FontStyle.Bold),Brushes.Black,new PointF(200,300));
  
   //画图例
   PointF boxOrigin = new PointF(210,330);
   PointF textOrigin = new PointF(235,326);
   for(int i=0;i<dt.Rows.Count;i++)
   {
    g.FillRectangle(new SolidBrush(ChartUtil.GetChartItemColor(i)),boxOrigin.X,boxOrigin.Y,20,10);
    g.DrawRectangle(Pens.Black,boxOrigin.X,boxOrigin.Y,20,10);
    g.DrawString(dt.Rows[i][0].ToString() + " - " + dt.Rows[i][1].ToString(),new Font("Tahoma",10),Brushes.Black,textOrigin);
    boxOrigin.Y += 15;
    textOrigin.Y += 15;
   }
   //输出图形
   bm.Save(Response.OutputStream, ImageFormat.Gif);
  
   //资源回收
   bm.Dispose();
   g.Dispose();
  }
调用
   Render2(200,300);

转载于:https://www.cnblogs.com/wuyq80/articles/453920.html