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;

namespace Example_6_7
{
	/// <summary>
	/// Summary description for WebForm1.
	/// </summary>
	public class DataToImage : System.Web.UI.Page
	{
		private ArrayList dataList = new ArrayList();

		private void Page_Load(object sender, System.EventArgs e)
		{
			if(!IsPostBack)
			{
				///繪制相應的圖像
				CreateImage(SetDataList(dataList));
			}
		}

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

			///添加圖片的起始坐標
			DataPoint pointzero = new DataPoint();
			pointzero.X = 0;
			pointzero.Y = 0;
			dataList.Add(pointzero);

			///添加圖片的最大坐標
			DataPoint pointwero = new DataPoint();
			pointwero.X = 200;
			pointwero.Y = 200;
			dataList.Add(pointwero);	
		
			///返回坐標數據
			return(dataList);
		}

		private void CreateImage(ArrayList dataList)
		{
			///判定數據是否正確，否則終止程序
			if(dataList.Count < 2)
			{
				Response.Write("從數據庫讀取數據錯誤！");
				return;
			}

			///創建背景圖片
			Bitmap mymap = new Bitmap(((DataPoint)dataList[1]).X * 2,((DataPoint)dataList[1]).Y * 2);

			///創建畫筆并設置其顏色
			Graphics graphic = Graphics.FromImage(mymap);
			Pen pen = new Pen(Color.Red,4);
			
			///繪制標準圓
			graphic.DrawEllipse(pen,((DataPoint)dataList[0]).X,((DataPoint)dataList[0]).Y,((DataPoint)dataList[1]).X,((DataPoint)dataList[1]).Y);
			
			///繪制三角形
			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));

			///保存并輸出繪制的圖片
			mymap.Save(Response.OutputStream,ImageFormat.Jpeg);

			///釋放占用的資源
			graphic.Dispose();
			mymap.Dispose();
		}

		#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>
	/// 定義坐標類
	/// </summary>
	public class DataPoint
	{
		public int X = 0;    ///保存坐標的X值
		public int Y = 0;    ///保存坐標的Y值
	}
}