ASP.Net绘制柱状图和曲线图示例
本周对ASP.Net绘制图形做了番学习，学会了如何用C#代码在页面上输出代码图形，但是效果不怎么好。示例如下。
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<staticData.Length;i++)
{
rect = new Rectangle(startX,heightValue +offsetY - staticData[i],rectWidth,staticData[i]);
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<dataList.Count;i++)
{
int[] staticData = (int[])dataList[i];
for(int j=0;j<staticData.Length;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<data.Length;i++)
{
if(data[i]>maxValue)
maxValue = data[i];
}
return maxValue;
}
private int MaxValue(ArrayList dataList)
{
int maxValue = 0;
for(int i=0;i<dataList.Count;i++)
{
int newMaxValue = MaxValue((int[])dataList[i]);
if( newMaxValue>maxValue)
maxValue = newMaxValue;
}
return maxValue;
}
private void ResetValue(int[] data,int ratio)
{
for(int i=0;i<data.Length;i++)
data[i] *= ratio;
}
private void ResetValue(ArrayList dataList,int ratio)
{
for(int i=0;i<dataList.Count;i++)
{
ResetValue((int[])dataList[i],ratio);
}
}
private int GetInnerGroupCount(ArrayList dataList)
{
int groupCount = 0;
for(int i=0;i<dataList.Count;i++)
{
int count = ((int[])dataList[i]).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;
}
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