GDI+ 的服务分为以下三个大类：
二维矢量图形
图像处理
版式
GDI+ 处理的时候实际上就是先建立画布，然后在画布上画图形的框架，接着是在框架里面填充东西，最后是释放资源
下面是一个饼图的例子
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace GDITest
{
/// <summary>
/// topn3dpie 的摘要说明。
/// </summary>
public class GDITest: System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
Response.ContentType = "image/gif";
const int width = 300, height = 300;
int x = 30, y = 50;
int pieWidth = 120, pieHeight = 40, pieShadow = 15;
int[] arrVote = {70,90,80,20,60,40};
Random oRan = new Random();
Bitmap objBitmap = new Bitmap(width-100, height-100);
Graphics objGraphics = Graphics.FromImage(objBitmap);
objGraphics.DrawRectangle(new Pen(Color.Black),0,0,width-100,height-100);
objGraphics.FillRectangle(new SolidBrush(Color.White), 1, 1,width - 2, height - 2);
SolidBrush objBrush = new SolidBrush(Color.Blue);
objGraphics.SmoothingMode = SmoothingMode.AntiAlias;
int iCurrentPos = 0;
Color[] arrColor = {Color.Red,Color.Red,Color.Red,Color.Red,Color.Red,Color.Red};
for(int i = arrVote.Length - 1 ; i >= 0; i--)
{
arrColor[i] = Color.FromArgb(oRan.Next(255), oRan.Next(255), oRan.Next(255));
}
for(int i = arrVote.Length - 1 ; i >= 0; i--)
{
objBrush.Color = arrColor[i];
for(int iLoop2 = 0; iLoop2 < pieShadow; iLoop2++)
objGraphics.FillPie(new HatchBrush(HatchStyle.Percent50,objBrush.Color),x, y + iLoop2, pieWidth, pieHeight, iCurrentPos, arrVote[i]);
iCurrentPos += arrVote[i];
}
iCurrentPos = 0;
for(int i = arrVote.Length - 1 ; i >= 0;i--)
{
objBrush.Color = arrColor[i];
objGraphics.FillPie(objBrush,x, y, pieWidth, pieHeight, iCurrentPos, arrVote[i]);
iCurrentPos += arrVote[i];
}
objBitmap.Save(Response.OutputStream, ImageFormat.Jpeg);
// clean up...
objGraphics.Dispose();
objBitmap.Dispose();
}
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}
