????? 当我们的软件需要各种饼状图和柱状图来表示数据时，我们或许会想到用offices中的图形控件或是第三方控件，但现在的第三方控件大都需要注册，有些免费的控件会有开发商的标记等。而对于使用Offices的图形控件来说，并不能在程序中得于很好控制，其使用的简易程度也较低，所以在这我给出在C#中使用GDI+实现饼状图和柱状图跟数据库联接显示数据的方法。
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 BaseLayer
{
?public class PieChart
?{
? public PieChart()
? {
? }
//Render是图形大标题，图开小标题，图形宽度，图形长度，饼图的数据集和饼图的数据集要表示出来的数据
? public Image Render(string title, string subTitle, int width, int height, DataSet chartData,int DataLine)
? {
?? const int SIDE_LENGTH = 400;
?? const int PIE_DIAMETER = 200;
?? DataTable dt = chartData.Tables[0];
??
?? //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[DataLine]);
?? }
?? //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);
?? //画饼图标题
?? g.DrawString(title,new Font("Tahoma",14),Brushes.Black,new PointF(5,5));
?? //画饼图的图例
?? g.DrawString(subTitle,new Font("Tahoma",12),Brushes.Black,new PointF(7,35));
?? //画饼图
?? float curAngle = 0;
?? float totalAngle = 0;
?? for(int i=0;i
??? curAngle = Convert.ToSingle(dt.Rows[i][DataLine]) / 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("图表说明",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
??? 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][DataLine]) / sumData * 100;
??? g.DrawString(dt.Rows[i][1].ToString() + " - " + dt.Rows[i][0].ToString() + " (" + percent.ToString("0") + "%)",new Font("Tahoma",10),Brushes.Black,textOrigin);
??? boxOrigin.Y += 15;
??? textOrigin.Y += 15;
?? }
?? //回收资源
?? g.Dispose();
?? return (Image) bm;
??
? }
?}
??
?//画条形图
?public class BarChart
?{
? public BarChart()
? {
? }
//Render是图形大标题，图开小标题，图形宽度，图形长度，饼图的数据集和饼图的数据集
? public Image Render(string title, string subTitle, int width, int height, DataSet chartData)
? {
?? 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 = chartData.Tables[0];
??
?? //计算最高的点
?? float highPoint = 0;
?? foreach(DataRow dr in dt.Rows)
?? {
??? if(highPoint
???? highPoint = Convert.ToSingle(dr[0]);
??? }
?? }
?? //建立一个Graphics对象实例
?? Bitmap bm = new Bitmap(width,height);
?? try
?? {
??? 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",14),Brushes.Black,new PointF(5,5));
??? //画小标题
??? g.DrawString(subTitle,new Font("Tahoma",12),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
???? barHeight = Convert.ToSingle(dt.Rows[i][0]) * 200 / highPoint * 1;
???? 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("图表说明",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
???? 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][1].ToString() + " - " + dt.Rows[i][0].ToString(),new Font("Tahoma",10),Brushes.Black,textOrigin);
???? boxOrigin.Y += 15;
???? textOrigin.Y += 15;
??? }
??? //输出图形
??? g.Dispose();
??? return bm;
?? }
?? catch
?? {
??? return bm;
?? }??
? }
?}
?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;
? }
?}
}
以上是一个完整的WinForm中制作饼状图和柱状图源程序，大家可以通过以上程序的更改，做出能满足自己程序的需要。