Dim objColor As Color
Select Case itemIndex
Case 0
objColor = Color.Blue
Case 1
objColor = Color.Red
Case 2
objColor = Color.Yellow
Case 3
objColor = Color.Purple
Case 4
objColor = Color.Orange
Case 5
objColor = Color.Brown
Case 6
objColor = Color.Gray
Case 7
objColor = Color.Maroon
Case 8
objColor = Color.Maroon
Case Else
objColor = Color.Blue
End Select
Return objColor
End Function
End Class
好了，我们的代码已经写完，点击“全部保存”按钮，然后按“F5”执行，看看最好的结果。如果没有错误的话，您将会看到如下的结果：
值得说明的是，上面只是简单地示例了如何利用.NET 框架类库中的图形类创建简单的图形，但.NET 框架类库中还提供了更高级的二维和矢量图形功能，利用这些高级功能，我们可以创建出二维或矢量的图形，那时，我们的图形看起来会更加形象。
本文所有代码在简体中文Windows 2000 + .NET FrameWork 1.0（英文正式版）+ .NET FrameWork SP1和Windows XP + .NET FrameWork 1.0（中文版）下调试通过。
C#代码
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Drawing.Imaging;
namespace eMeng.Exam
{
/// <summary>
/// Chart 的摘要说明。
/// </summary>
public class Chart : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
Bitmap objBitMap = new Bitmap(400, 200);
Graphics objGraphics;
objGraphics = Graphics.FromImage(objBitMap);
objGraphics.Clear(Color.White);
int arrValues = {100,135,115,125,75,120};
string arrValueNames = new string{"一月","二月","三月","四月","五月","六月"};
objGraphics.DrawString(" X 公司上半年销售情况",
new Font("宋体", 16), Brushes.Black, new PointF(5, 5));
PointF symbolLeg = new PointF(335, 20);
PointF descLeg = new PointF(360, 16);
for (int i = 0; i < arrValueNames.Length; i++)
{
objGraphics.FillRectangle(new SolidBrush(GetColor(i)), symbolLeg.X, symbolLeg.Y, 20, 10);
objGraphics.DrawRectangle(Pens.Black, symbolLeg.X, symbolLeg.Y, 20, 10);
objGraphics.DrawString(arrValueNames[i].ToString(), new Font("宋体", 10), Brushes.Black, descLeg);
symbolLeg.Y += 15;
descLeg.Y += 15;
}
for (int i = 0; i < arrValues.Length; i++)
{
objGraphics.FillRectangle(new SolidBrush(GetColor(i)), (i * 35) + 15, 200 - arrValues[i], 20,
arrValues[i] + 5);
objGraphics.DrawRectangle(Pens.Black, (i * 35) + 15, 200 - arrValues[i], 20, arrValues[i] + 5);
}
float sglCurrentAngle = 0;
float sglTotalAngle = 0;
float sglTotalValues = 0;
for (int i = 0; i <= arrValues.Length - 1; i++)
{
sglTotalValues += arrValues[i];
}
for (int i = 0; i < arrValues.Length; i++)
{
sglCurrentAngle = arrValues[i] / sglTotalValues * 360;
objGraphics.FillPie(new SolidBrush(GetColor(i))
