如何在C#的WinForm中制作饼状图和柱状图

//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<Convert.ToSingle(dr[0]))
{
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<dt.Rows.Count;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<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][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;
}
}
}

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