mapstream.aspx.cs

map server code iot can be used for developing map appliaction to render the map on .NET plateform

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.IO;

namespace TutorialMapServer
{
	/// <summary>
	/// MapStream produce an imagestream for the ibMap control at the Default.aspx page
	/// </summary>
	public class MapStream : System.Web.UI.Page
	{
		//private variable for this class
		mapObj map;
		rectObj originalExtent;

		/// <summary>
		/// Zoom Mode Enumerator
		/// </summary>
		private enum ZOOMMODE
		{
			ZoomIn = 0,
			ZoomOut = 1
		}

		/// <summary>
		/// Do a Map Action and send an image stream
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void Page_Load(object sender, System.EventArgs e)
		{
			//read map if existing, otherwhise create a new one from map file
			map = (mapObj)Session["MAP"];
			if(map==null)
			{
				map = new mapObj(System.Configuration.ConfigurationSettings.AppSettings["mapFilePath"].ToString());
				originalExtent = new rectObj(map.extent.minx, map.extent.miny, map.extent.maxx, map.extent.maxy, 0);
				Session["ORIGINALEXTENT"]=originalExtent;
			}
			originalExtent = (rectObj)Session["ORIGINALEXTENT"];
			//read x,y
			Double x=0;
			Double y=0;
			if(Request.QueryString["X"]!=null && Request.QueryString["Y"]!=null)
			{
				x = Double.Parse(Request.QueryString["X"].ToString());
				y = Double.Parse(Request.QueryString["Y"].ToString());
			}
			//let's see which action is necessary
			String Action = Request.QueryString["ACTION"].ToString().ToUpper();
			switch(Action)
			{
				case "ZOOMIN":
					DoZoom(ZOOMMODE.ZoomIn,x,y);
					break;
				case "ZOOMOUT":
					DoZoom(ZOOMMODE.ZoomOut,x,y);
					break;
				case "FULLEXTENT":
					DoZoomFullExtent();
					break;
			}
			//refresh
			RefreshMap();
			//store in session
			Session["MAP"]=map;
		}

		/// <summary>
		/// Refresh MapServer map and send the image stream to output
		/// </summary>
		private void RefreshMap()
		{
			using(imageObj image = map.draw())
			{
				byte[] img = image.getBytes();
				using (MemoryStream ms = new MemoryStream(img))
				{
					System.Drawing.Image mapimage = System.Drawing.Image.FromStream(ms);	
					Bitmap bitmap = (Bitmap)mapimage;
					bitmap.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
				}				
			}
		}

		/// <summary>
		/// Do a zoom in or zoom out
		/// </summary>
		/// <param name="zoomMode">zoomin or zoomout</param>
		/// <param name="x">x image coordinate</param>
		/// <param name="y">y image coordinate</param>
		private void DoZoom(ZOOMMODE zoomMode, Double x, Double y)
		{
			//Do Zoom In
			if(zoomMode==ZOOMMODE.ZoomIn)
			{
				map.zoomPoint(2, new pointObj(x,y,0,0), map.width, map.height, map.extent, null);
			}
			//Do Zoom Out
			if(zoomMode==ZOOMMODE.ZoomOut)
			{
				map.zoomPoint(-2, new pointObj(x,y,0,0), map.width, map.height, map.extent, null);
			}
		}

		/// <summary>
		/// Do a Full Extent (return to Origina Extent)
		/// </summary>
		private void DoZoomFullExtent()
		{
			map.extent = originalExtent;
		}

		#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
	}
}