map.cs

Sharp Map 用于制作GIS系统S harp Map 用于制作GIS系统S harp Map 用于制作GIS系统

// Copyright 2005, 2006 - Morten Nielsen (www.iter.dk)
//
// This file is part of SharpMap.
// SharpMap is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
// 
// SharpMap is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public License
// along with SharpMap; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 

using System;
using System.Collections.Generic;
using System.Text;


namespace SharpMap
{
	/// <summary>
	/// Map class
	/// </summary>
	/// <example>
	/// Creating a new map instance, adding layers and rendering the map:
	/// <code lang="C#">
	/// SharpMap.Map myMap = new SharpMap.Map(picMap.Size);
	/// myMap.MinimumZoom = 100;
	/// myMap.BackgroundColor = Color.White;
	/// 
	/// SharpMap.Layers.VectorLayer myLayer = new SharpMap.Layers.VectorLayer("My layer");
	///	string ConnStr = "Server=127.0.0.1;Port=5432;User Id=postgres;Password=password;Database=myGisDb;";
	/// myLayer.DataSource = new SharpMap.Data.Providers.PostGIS(ConnStr, "myTable", "the_geom", 32632);
	/// myLayer.FillStyle = new SolidBrush(Color.FromArgb(240,240,240)); //Applies to polygon types only
	///	myLayer.OutlineStyle = new Pen(Color.Blue, 1); //Applies to polygon and linetypes only
	/// //Setup linestyle (applies to line types only)
	///	myLayer.Style.Line.Width = 2;
	///	myLayer.Style.Line.Color = Color.Black;
	///	myLayer.Style.Line.EndCap = System.Drawing.Drawing2D.LineCap.Round; //Round end
	///	myLayer.Style.Line.StartCap = layRailroad.LineStyle.EndCap; //Round start
	///	myLayer.Style.Line.DashPattern = new float[] { 4.0f, 2.0f }; //Dashed linestyle
	///	myLayer.Style.EnableOutline = true;
	///	myLayer.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias; //Render smooth lines
	///	myLayer.MaxVisible = 40000;
	/// 
	/// myMap.Layers.Add(myLayer);
	/// // [add more layers...]
	/// 
	/// myMap.Center = new SharpMap.Geometries.Point(725000, 6180000); //Set center of map
	///	myMap.Zoom = 1200; //Set zoom level
	/// myMap.Size = new System.Drawing.Size(300,200); //Set output size
	/// 
	/// System.Drawing.Image imgMap = myMap.GetMap(); //Renders the map
	/// </code>
	/// </example>
	public class Map : IDisposable
	{
		/// <summary>
		/// Used for converting numbers to/from strings
		/// </summary>
		internal static System.Globalization.NumberFormatInfo numberFormat_EnUS = new System.Globalization.CultureInfo("en-US", false).NumberFormat;

		/// <summary>
		/// Initializes a new map
		/// </summary>
		public Map() : this(new System.Drawing.Size(300,150))
		{
		}
		
		/// <summary>
		/// Initializes a new map
		/// </summary>
		/// <param name="size">Size of map in pixels</param>
		public Map(System.Drawing.Size size)
		{
			this.Size = size;
			this.Layers = new List<SharpMap.Layers.ILayer>();
			this.BackColor = System.Drawing.Color.Transparent;
			this._MaximumZoom = double.MaxValue;
			this._MinimumZoom = 0;
			_MapTransform = new System.Drawing.Drawing2D.Matrix();
			MapTransformInverted = new System.Drawing.Drawing2D.Matrix();
			_Center = new SharpMap.Geometries.Point(0, 0);
			_Zoom = 1;
			_PixelAspectRatio = 1.0;
		}		

		/// <summary>
		/// Disposes the map object
		/// </summary>
		public void Dispose()
		{
			foreach (SharpMap.Layers.Layer layer in this.Layers)
				if (layer is IDisposable)
					((IDisposable)layer).Dispose();
			this.Layers.Clear();
		}

		#region Events
		/// <summary>
		/// EventHandler for event fired when the maps layer list has been changed
		/// </summary>
		public delegate void LayersChangedEventHandler();

		/// <summary>
		/// Event fired when the maps layer list have been changed
		/// </summary>
		public event LayersChangedEventHandler LayersChanged;

		/// <summary>
		/// EventHandler for event fired when the zoomlevel or the center point has been changed
		/// </summary>
		public delegate void MapViewChangedHandler();
		
		/// <summary>
		/// Event fired when the zoomlevel or the center point has been changed
		/// </summary>
		public event MapViewChangedHandler MapViewOnChange;


		/// <summary>
		/// EventHandler for event fired when all layers have been rendered
		/// </summary>
		public delegate void MapRenderedEventHandler(System.Drawing.Graphics g);

		/// <summary>
		/// Event fired when all layers have been rendered
		/// </summary>
		public event MapRenderedEventHandler MapRendered;
		#endregion

		#region Methods

		/// <summary>
		/// Renders the map to an image
		/// </summary>
		/// <returns></returns>
		public System.Drawing.Image GetMap()
		{
			if (Layers == null || Layers.Count == 0)
				throw new InvalidOperationException("No layers to render");

			System.Drawing.Image img = new System.Drawing.Bitmap(this.Size.Width, this.Size.Height);
			System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(img);
			g.Transform = this.MapTransform;
			g.Clear(this.BackColor);
			g.PageUnit = System.Drawing.GraphicsUnit.Pixel;
			int SRID = (Layers.Count > 0 ? Layers[0].SRID : -1); //Get the SRID of the first layer
			for (int i = 0; i < _Layers.Count; i++)
			{
				if (_Layers[i].Enabled && _Layers[i].MaxVisible >= this.Zoom && _Layers[i].MinVisible < this.Zoom)
					_Layers[i].Render(g, this);
			}
			if (MapRendered != null) MapRendered(g); //Fire render event
			g.Dispose();
			return img;
		}

		/// <summary>
		/// Returns an enumerable for all layers containing the search parameter in the LayerName property
		/// </summary>
		/// <param name="layername">Search parameter</param>
		/// <returns>IEnumerable</returns>
		public IEnumerable<SharpMap.Layers.ILayer> FindLayer(string layername)
		{
			foreach (SharpMap.Layers.ILayer l in this.Layers)
				if (l.LayerName.Contains(layername))
					yield return l;
		}

		/// <summary>
		/// Returns a layer by its name
		/// </summary>
		/// <param name="name">Name of layer</param>
		/// <returns>Layer</returns>
		public SharpMap.Layers.ILayer GetLayerByName(string name)
		{
			return _Layers.Find(delegate(SharpMap.Layers.ILayer layer) { return layer.LayerName.Equals(name); });
		}

		/// <summary>
		/// Zooms to the extents of all layers
		/// </summary>
		public void ZoomToExtents()
		{
			this.ZoomToBox(this.GetExtents());
		}

		/// <summary>
		/// Zooms the map to fit a bounding box
		/// </summary>
		/// <remarks>
		/// NOTE: If the aspect ratio of the box and the aspect ratio of the mapsize
		/// isn't the same, the resulting map-envelope will be adjusted so that it contains
		/// the bounding box, thus making the resulting envelope larger!
		/// </remarks>
		/// <param name="bbox"></param>
		public void ZoomToBox(SharpMap.Geometries.BoundingBox bbox)
		{
			this._Zoom = bbox.Width; //Set the private center value so we only fire one MapOnViewChange event
			if (this.Envelope.Height < bbox.Height)
				this._Zoom *= bbox.Height / this.Envelope.Height;
			this.Center = bbox.GetCentroid();			
		}

		/// <summary>
		/// Converts a point from world coordinates to image coordinates based on the current
		/// zoom, center and mapsize.
		/// </summary>
		/// <param name="p">Point in world coordinates</param>
		/// <returns>Point in image coordinates</returns>
		public System.Drawing.PointF WorldToImage(SharpMap.Geometries.Point p)
		{
			return Utilities.Transform.WorldtoMap(p, this);
		}
		/// <summary>
		/// Converts a point from image coordinates to world coordinates based on the current
		/// zoom, center and mapsize.
		/// </summary>
		/// <param name="p">Point in image coordinates</param>
		/// <returns>Point in world coordinates</returns>
		public SharpMap.Geometries.Point ImageToWorld(System.Drawing.PointF p)
		{
			return Utilities.Transform.MapToWorld(p, this);
		}

		#endregion

		#region Properties

		/// <summary>
		/// Gets the extents of the current map based on the current zoom, center and mapsize
		/// </summary>
		public SharpMap.Geometries.BoundingBox Envelope
		{
			get {
				return new SharpMap.Geometries.BoundingBox(
					new SharpMap.Geometries.Point(this.Center.X - this.Zoom * .5, this.Center.Y - this.MapHeight * .5),
					new SharpMap.Geometries.Point(this.Center.X + this.Zoom * .5, this.Center.Y + this.MapHeight * .5));
			}
		}

		private System.Drawing.Drawing2D.Matrix _MapTransform;
		internal System.Drawing.Drawing2D.Matrix MapTransformInverted;

		/// <summary>
		/// Using the <see cref="MapTransform"/> you can alter the coordinate system of the map rendering.
		/// This makes it possible to rotate or rescale the image, for instance to have another direction than north upwards.
		/// </summary>
		/// <example>