C#绘图(可以处理负值)

 

using System;
using System.IO;//用于文件存取
using System.Data;//用于数据访问
using System.Drawing;//提供画GDI+图形的基本功能
using System.Drawing.Text;//提供画GDI+图形的高级功能
using System.Drawing.Drawing2D;//提供画高级二维，矢量图形功能
using System.Drawing.Imaging;//提供画GDI+图形的高级功能

namespace Drawpicture
 {
  ///

  /// BarChart 的摘要说明。
  ///

  public class BarChart
  {
   private   int Pic_Width = 410;
   private   int Pic_Height = 320;
           
   public static bool hasNeg = false;

   private const string FontWord = "Arial";
   private const int FontSize = 9;

   public  int SIDE_WIDTH = 400;
   public  int SIDE_HEIGHT = 400;
   private const int CHART_TOP = 60;
   private  int CHART_HEIGHT = 300;
   private const int CHART_LEFT = 60;
   private const int CHART_WIDTH = 300;

   public void Render(string[] word,int[] data, out string fileName)
   {
    
    for(int i=0;i    {
     if(data[i]<0)
     {
      Pic_Height *=2;
      hasNeg = true;
      SIDE_HEIGHT = (int)(SIDE_HEIGHT*1.5);
      CHART_HEIGHT =(int)(CHART_HEIGHT*0.3);
      break;
     }
    }
    ChartUtil cu = new ChartUtil();

    PointF[] zuoBiaoStart;
    PointF[] zuoBiaoEnd;
    Graphics g;
    Bitmap bm;
    createCanvas(out bm, out g, out zuoBiaoEnd, out zuoBiaoStart,cu);

    //画坐标轴
    int chiDu = drawAxes(data, zuoBiaoStart, g, zuoBiaoEnd,cu);

    //画条形图
    float barWidth = CHART_WIDTH / (2 * 2);
    PointF barOrigin = new PointF(CHART_LEFT + (barWidth / 2),0);
    float barHeight = 2;
    for(int i=0;i<2;i++)
    {
     barHeight = ((float)data[i]/chiDu) *(CHART_HEIGHT/5) ;
     if(barHeight<0)
     {
      barOrigin.Y = CHART_TOP + CHART_HEIGHT;
     }
     else
     {
      barOrigin.Y = CHART_TOP + CHART_HEIGHT - barHeight;
     }
     
     g.FillRectangle(new SolidBrush(ChartUtil.GetChartItemColor(i)),barOrigin.X,barOrigin.Y,barWidth,Math.Abs(barHeight));
     barOrigin.X = barOrigin.X + (barWidth * 2);
    }
    
  
    //画右上角的说明图形
    drawInstruction(CHART_LEFT, CHART_HEIGHT, CHART_TOP, g, word, data);

    //输出图形
    fileName = cu.PicPath + Guid.NewGuid().ToString() + ".gif";
    bm.Save(fileName, ImageFormat.Gif);
  
    //资源回收
    bm.Dispose();
    g.Dispose();
   }

   private  int drawAxes(int[] data, PointF[] zuoBiaoStart, Graphics g, PointF[] zuoBiaoEnd,ChartUtil cu)
   {
    int chiDu =1;
    int[] t = cu.getZuoBiaoValue(data,out chiDu);
    for(int i=0;i    {
     PointF txtPos = new PointF();
     txtPos.X = zuoBiaoStart[i].X -50;
     txtPos.Y = zuoBiaoStart[i].Y - 5;
     g.DrawString(t[i].ToString(),new Font(FontWord,8),Brushes.Black,txtPos);
     g.DrawLine(Pens.Black,zuoBiaoStart[i],zuoBiaoEnd[i]);   
    }
    return chiDu;
   }

   private  void createCanvas(out Bitmap bm, out Graphics g, out PointF[] zuoBiaoEnd, out PointF[] zuoBiaoStart,ChartUtil cu)
   {
    //建立一个Graphics对象实例
    bm = new Bitmap(Pic_Width,Pic_Height);
    g = Graphics.FromImage(bm);
    //设置条图图形和文字属性

    g.ScaleTransform((Convert.ToSingle(Pic_Width))/SIDE_WIDTH,(Convert.ToSingle(Pic_Height))/SIDE_HEIGHT);
    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_WIDTH-1,SIDE_HEIGHT-1);
 
    //设置条形图的边
    g.DrawRectangle(new Pen(Color.Black,1),CHART_LEFT,CHART_TOP,CHART_WIDTH, CHART_HEIGHT);
    if(hasNeg)
    {
     g.DrawRectangle(new Pen(Color.Black,1),CHART_LEFT,CHART_TOP+CHART_HEIGHT,CHART_WIDTH, CHART_HEIGHT);
    }

    zuoBiaoEnd = null;
   zuoBiaoStart = cu.getZuoBiaoPoint(new PointF(CHART_TOP,CHART_LEFT),CHART_HEIGHT,CHART_WIDTH,out zuoBiaoEnd,hasNeg);
   }

   private  void drawInstruction(int CHART_LEFT, int CHART_HEIGHT, int CHART_TOP, Graphics g, string[] word, int[] data)
   {
    PointF colsNamePoint = new PointF(CHART_LEFT + 55,CHART_HEIGHT + CHART_TOP + 2);
    if(hasNeg)
    {
     colsNamePoint = new PointF(CHART_LEFT + 55,CHART_HEIGHT*2 + CHART_TOP + 2);
    }
    
    PointF boxOrigin = new PointF(Pic_Width*5/6-30,CHART_TOP*1/3);
    PointF textOrigin = new PointF(Pic_Width*4/5+8,CHART_TOP*1/3 -3 );
    for(int i=0;i<2;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(word[i],new Font(FontWord,FontSize),Brushes.DarkBlue,colsNamePoint);
     g.DrawString(data[i].ToString(),new Font(FontWord,FontSize),Brushes.Black,textOrigin);
     colsNamePoint.X += 150;
     boxOrigin.Y += 15;
     textOrigin.Y += 15;
    }
   }
  }
  public class ChartUtil
  {
   
   public  readonly string PicPath = System.AppDomain.CurrentDomain.BaseDirectory + "Temp/";

   public  PointF[] getZuoBiaoPoint(PointF orign,int height,int width,out PointF[] endPoint,bool hasNeg)
   {
    int num = 6;
    if(hasNeg) num = 11;
    PointF[] startPoint = new PointF[num];
    endPoint = new PointF[num];

    for(int i =0;i    {
     PointF pfStart = new PointF();
     PointF pfEnd = new PointF();
     pfStart.X = orign.X;
     pfEnd.X = orign.X + width;
     pfStart.Y = orign.Y + i*height/5;
     pfEnd.Y = pfStart.Y;
     startPoint[i] = pfStart;
     endPoint[i] = pfEnd;
    }
    return startPoint;
   }
   public  int[] getZuoBiaoValue(int[] data,out int chidu)
   {
    int[] result = new Int32[11];
    int Max = data[0];
    
    for(int i=0;i    {
     if(Max < data[i])
      Max = data[i];
    }
    string strMax = Max + "";
    chidu =(int)((Convert.ToInt32(strMax.Substring(0,1)) +1)* Math.Pow(10,strMax.Length-1))/5;
    for(int i=0;i    {
     result[i] = chidu* (5-i) ;
    }
    return result;
   }
   
   #region get color
   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;
   }
   #endregion
  }
 }