mycreateimage.aspx.cs

ASP C#代码实例 适合初学人士学习使用

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.Drawing2D;
using System.Drawing.Text;
using System.Drawing.Imaging;
using System.IO;

namespace Example_11_6
{
	/// <summary>
	/// Summary description for MyCreateImage.
	/// </summary>
	public class MyCreateImage : System.Web.UI.Page
	{
		private ArrayList dataList = new ArrayList();

		private void Page_Load(object sender, System.EventArgs e)
		{
			if(!IsPostBack)
			{
				///绘制相应的图像
				CreateImage(SetDataList(dataList));
			}
		}

		private ArrayList SetDataList(ArrayList dataList)
		{
			dataList.Clear();

			///添加图片的起始坐标
			DataPoint pointzero = new DataPoint();
			pointzero.X = 0;
			pointzero.Y = 0;
			dataList.Add(pointzero);

			///添加图片的最大坐标
			DataPoint pointwero = new DataPoint();
			pointwero.X = 200;
			pointwero.Y = 200;
			dataList.Add(pointwero);	
		
			///返回坐标数据
			return(dataList);
		}

		private void CreateImage(ArrayList dataList)
		{
			///判定数据是否正确，否则终止程序
			if(dataList.Count < 2)
			{
				Response.Write("从数据库读取数据错误！");
				return;
			}

			///创建背景图片
			Bitmap mymap = new Bitmap(((DataPoint)dataList[1]).X * 2,((DataPoint)dataList[1]).Y * 2);

			///创建画笔并设置其颜色
			Graphics graphic = Graphics.FromImage(mymap);
			Pen pen = new Pen(Color.Red,4);
			
			///绘制标准圆
			graphic.DrawEllipse(pen,((DataPoint)dataList[0]).X,((DataPoint)dataList[0]).Y,((DataPoint)dataList[1]).X,((DataPoint)dataList[1]).Y);
			
			///绘制三角形
			graphic.DrawLine(new Pen(Color.Green,3),new Point(((DataPoint)dataList[0]).X,((DataPoint)dataList[1]).Y),new Point(((DataPoint)dataList[1]).X,((DataPoint)dataList[1]).Y));
			graphic.DrawLine(new Pen(Color.Green,3),new Point(((DataPoint)dataList[1]).X,((DataPoint)dataList[1]).Y),new Point(((DataPoint)dataList[1]).X,((DataPoint)dataList[1]).Y * 2));
			graphic.DrawLine(new Pen(Color.Green,3),new Point(((DataPoint)dataList[1]).X,((DataPoint)dataList[1]).Y * 2),new Point(((DataPoint)dataList[0]).X,((DataPoint)dataList[1]).Y));

			///绘制正方形
			graphic.DrawRectangle(new Pen(Color.Yellow,3),225,75,((DataPoint)dataList[1]).Y / 2 + 50,((DataPoint)dataList[1]).Y);
			
			///保存并输出绘制的图片
//			mymap.Save(Response.OutputStream,ImageFormat.Jpeg);
			OutPicture(mymap);

			///释放占用的资源
			graphic.Dispose();
			mymap.Dispose();
		}

		private void OutPicture(Bitmap map)
		{
			///定义输出的内存流
			MemoryStream ms = new MemoryStream();
			///保存图像	
			map.Save(ms,ImageFormat.Png);
			///清空网页的输出
			Response.ClearContent();

			///设置网页输出的格式
			Response.ContentType = "Image/png";
			///输出图像
			Response.BinaryWrite(ms.ToArray());
			Response.End();
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.Load += new System.EventHandler(this.Page_Load);
		}
		#endregion
	}

	/// <summary>
	/// 定义坐标类
	/// </summary>
	public class DataPoint
	{
		public int X = 0;    ///保存坐标的X值
		public int Y = 0;    ///保存坐标的Y值
	}
}