绘图Draw

public class WebForm1 : System.Web.UI.Page
{
  private void Page_Load(object sender, System.EventArgs e)
  {
   //This is the interface to outer usage
   int widthValue = 800;
   int heightValue = 500;
   String xTitle,yTitle;
   int offsetX = 20;
   int offsetY = 20;
   //柱状图之间的间距
   int spaceSpan = 15;
   
   xTitle = "Time";
   yTitle = "Sum";

   Bitmap imgBitmap = new Bitmap(widthValue+5*offsetX,heightValue+offsetY*2,PixelFormat.Format32bppPArgb);
   Graphics g = Graphics.FromImage(imgBitmap);
   g.Clear(Color.Snow);
   Pen linePen = new Pen(Color.Black);
   linePen.Width = 2;
   //Draw Title
   Font txtFont = new Font("Courier",10,GraphicsUnit.Point);
   String title= "This is the title to be displayed";
   g.DrawString(title,txtFont,Brushes.Blue,new PointF(imgBitmap.Width/2,0));
   Point original = new Point(offsetX,heightValue+offsetY);
   Point xEndPonit = new Point(widthValue+offsetX ,heightValue+offsetY); 
   Point yEndPonit = new Point(offsetX,0);
   //X coordinate
   g.DrawLine(linePen,original,xEndPonit);
   //Y Coordinate
   g.DrawLine(linePen,original,yEndPonit);
   //Draw arrows
   Point leftArrowStart = new Point(offsetX*3/4 ,offsetY/3);
   Point rightArrowEnd = new Point(offsetX*5/4,offsetY/3);
   g.DrawLine(linePen,leftArrowStart,yEndPonit);
   g.DrawLine(linePen,yEndPonit,rightArrowEnd);
   
   Point topArrowStart = new Point(widthValue + offsetX*3/4,heightValue +  offsetY*3/4);
   Point bottomArrowEnd = new Point(widthValue+ offsetX*3/4,heightValue  + offsetY*5/4);
   g.DrawLine(linePen,topArrowStart,xEndPonit);
   g.DrawLine(linePen,xEndPonit,bottomArrowEnd);
   
   
   //Draw X-Title
g.DrawString(xTitle,txtFont,Brushes.Blue,new PointF(bottomArrowEnd.X-g.MeasureString(xTitle,txtFont).Width,topArrowStart.Y +10));
   StringFormat f = new StringFormat();
   //f.Alignment = StringAlignment.Center;
   //Draw Y-Title
   f.LineAlignment = StringAlignment.Center;
   g.DrawString(yTitle,txtFont,Brushes.Blue,new PointF(offsetX * 5/3,15),f);
   
   //画单个柱状图的代码
   
   //测试数据
   /**
   int[] staticData = new int[]{20,30,80,50,200,120,20,30,80,50,200,120,60,90,140};
   
   int maxValue = MaxValue(staticData);
   
   int ratio = heightValue/maxValue;
   int groupCount = staticData.Length; //柱状图组数
   ResetValue(staticData,ratio);
   
   int rectWidth = (widthValue - (groupCount +1)*spaceSpan )/ groupCount;
   Rectangle rect;
   int startX = offsetX + spaceSpan; //起始坐标点
   for(int i=0;i
   {
    rect = new Rectangle(startX,heightValue +offsetY - staticData,rectWidth,staticData);
    g.DrawRectangle(Pens.Green,rect);
    g.FillRectangle(Brushes.Green,rect);
    startX = startX + rectWidth + spaceSpan;
   }
   **/
//   Type t = dataList.GetType();
//   if(t.IsArray)
//   {
//   }
   //画分组柱状图代码
   ArrayList dataList = new ArrayList();
   int[] data1= new int[]{20,30,50,100};
   int[] data2 = new int[]{50,60,30,30};
   int[] data3 = new int[]{80,50,60,85};
   int[] data4= new int[]{20,30,90,58};
   int[] data5 = new int[]{50,60,30,30};
   int[] data6 = new int[]{80,50,60,85};
   int[] data7= new int[]{20,30,90,58};
   dataList.Add(data1);
   dataList.Add(data2);
   dataList.Add(data3);
   dataList.Add(data4);
   dataList.Add(data5);
   dataList.Add(data6);
   dataList.Add(data7);
   int maxValue = MaxValue(dataList);
   int ratio = heightValue/maxValue;
   int groupCount = dataList.Count; //柱状图组数
   ResetValue(dataList,ratio);
   
   //根据比率画坐标
   //Draw X-Grids, The height value is divided into 10 parts
   int heightStep = heightValue/10;
   Point point1,point2;
   for(int i=1;i<=10;i++)
   {
    point1 = new Point(offsetX*3/4,offsetY+heightValue - heightStep*i);
    point2 = new Point(offsetX,point1.Y);
    g.DrawLine(Pens.Black,point1,point2);
    String text = maxValue/10*i+"";
    g.DrawString(text,txtFont,Brushes.Blue,new PointF(-2,point1.Y));
   }
   //画坐标结束
   int rectWidth = (widthValue - (groupCount +1)*spaceSpan )/ groupCount;
   int innerGroupCount = GetInnerGroupCount(dataList);
   int innerWidth = rectWidth / innerGroupCount;
   Rectangle rect;
   int startX = offsetX + spaceSpan; //起始坐标点
   for(int i=0;i
   {
    int[] staticData = (int[])dataList;
    for(int j=0;j
    {
     rect = new Rectangle(startX,heightValue +offsetY - staticData[j],innerWidth,staticData[j]);
     g.DrawRectangle(GetPenColor(j),rect);
     g.FillRectangle(GetBrushColor(j),rect);
     startX = startX + innerWidth;
    }
    startX = startX + spaceSpan;
   }
   //画曲线
   Point pnt1 = new Point(200+offsetX,heightValue+offsetY-300);
   Point pnt2 = new Point(300+offsetX,heightValue+offsetY-500);
   Point pnt3 = new Point(400+offsetX,heightValue+offsetY-300);
   Point pnt4 = new Point(600+offsetX,heightValue+offsetY-600);
   g.DrawCurve(Pens.Purple,new Point[]{pnt1,pnt2,pnt3,pnt4});
   //画饼图
   g.DrawPie ( Pens.Red , 50 , 50 , 150 , 150 , 0 , 30 ) ;
   imgBitmap.Save(Response.OutputStream,ImageFormat.Gif);
  }

代码中涉及到的函数如下：
private int MaxValue(int[] data)
  {
   int maxValue = 0;
   for(int i=0;i
   {
    if(data>maxValue)
     maxValue = data;
   }
   return maxValue;
  }
  private int MaxValue(ArrayList dataList)
  {
   int maxValue = 0;
   for(int i=0;i
   {
    int newMaxValue = MaxValue((int[])dataList);
    if( newMaxValue>maxValue)
     maxValue = newMaxValue;
   }
   return maxValue;
  }
  private void ResetValue(int[] data,int ratio)
  {
   for(int i=0;i
    data *= ratio;
  }
  private void ResetValue(ArrayList dataList,int ratio)
  {
   for(int i=0;i
   {
    ResetValue((int[])dataList,ratio);
   }
  }
  private int GetInnerGroupCount(ArrayList dataList)
  {
   int groupCount = 0;
   for(int i=0;i
   {
    int count = ((int[])dataList).Length;
    if(count>groupCount)
     groupCount = count;
   }
   return groupCount;
  }
  private Pen GetPenColor(int index)
  {
   Pen linePen = new Pen(Color.Black);
   linePen.Width = 1;
   linePen.CompoundArray = new float[]{0.0F,0.2F};
   switch(index)
   {
    case 0:
     linePen.Color = Color.Gray;
     break;
    case 1:
     linePen.Color = Color.Green;
     break;
    case 2:
      linePen.Color = Color.Blue;
     break;
    case 3:
     linePen.Color = Color.Purple;
     break;
   }
   return linePen;
  }
  private Brush GetBrushColor(int index)
  {
   switch(index)
   {
    case 0:
     return Brushes.Gray;
    case 1:
     return Brushes.Green;
    case 2:
     return Brushes.Blue;
    case 3:
     return Brushes.Purple;
   }
   return Brushes.Red;
  }