如何使用ArcGIS API for Flex 调用天地图

本文讲述如何使用ArcGIS API for Flex调用天地图的服务，那么下面我就把代码共享给大家。 实现的方式主要是扩展ArcGIS API for Flex中的TiledMapLayer，去读取天地图的切片: packagecom.esrichina { importcom.esri.ags.SpatialReference; importcom.esri.ag

本文讲述如何使用ArcGIS API for Flex调用天地图的服务，那么下面我就把代码共享给大家。 实现的方式主要是扩展ArcGIS API for Flex中的TiledMapLayer，去读取天地图的切片:
package com.esrichina { import com.esri.ags.SpatialReference; import com.esri.ags.geometry.Extent; import com.esri.ags.geometry.MapPoint; import com.esri.ags.layers.LOD; import com.esri.ags.layers.TileInfo; import com.esri.ags.layers.TiledMapServiceLayer; import flash.net.URLRequest; public class tdtMapslayer extends TiledMapServiceLayer { public function tdtMapslayer() { super(); buildTileInfo(); setLoaded(true); } private var _tileInfo:TileInfo=new TileInfo(); private var _baseURL:String=""; override public function get fullExtent():Extent { return new Extent(-180, -90, 180, 90, new SpatialReference(4326)); } override public function get initialExtent():Extent { return new Extent(-180, -90, 180, 90, new SpatialReference(4326)); } override public function get spatialReference():SpatialReference { return new SpatialReference(4326); } override public function get tileInfo():TileInfo { return _tileInfo; } override protected function getTileURL(level:Number, row:Number, col:Number):URLRequest { var url:String="http://tile2.tianditu.com/DataServer?T=A0512_EMap&" + "X=" + col + "&" + "Y=" + row + "&" + "L=" + level; return new URLRequest(url); } private function buildTileInfo():void { _tileInfo.height=256; _tileInfo.width=256; _tileInfo.origin=new MapPoint(-90 ,45 ,new SpatialReference(4326)); _tileInfo.spatialReference=new SpatialReference(4326); _tileInfo.lods = [ new LOD(1, 0.3515625, 147748799.285417), new LOD(2, 0.17578125, 73874399.6427087), new LOD(3, 0.087890625, 36937199.8213544), new LOD(4, 0.0439453125, 18468599.9106772), new LOD(5, 0.02197265625, 9234299.95533859), new LOD(6, 0.010986328125, 4617149.97766929), new LOD(7, 0.0054931640625, 2308574.98883465), new LOD(8, 0.00274658203125, 1154287.49441732),

继承 TiledMapServiceLayer 编写SXGeoTileLayer 类
package ext
{

import com.esri.ags.SpatialReference;
import com.esri.ags.geometry.Extent;
import com.esri.ags.geometry.MapPoint;
import com.esri.ags.layers.supportClasses.LOD;
import com.esri.ags.layers.supportClasses.TileInfo;
import com.esri.ags.layers.TiledMapServiceLayer;
import com.esri.ags.layers.TiledMapServiceLayer;

import flash.geom.Point;
import flash.net.URLRequest;

/**
* SXGeoTileLayer 吉奥的地图服务
*/
public class SXGeoTileLayer extends TiledMapServiceLayer
{
//--------------------------------------------------------------------------
//
// Constructor
//
//--------------------------------------------------------------------------

/**
* Creates a new PortlandTiledMapServiceLayer object.
*/
public function SXGeoTileLayer()
{
super();

buildTileInfo(); // to create our hardcoded tileInfo

setLoaded(true); // Map will only use loaded layers
}

//--------------------------------------------------------------------------
//
// Variables
//
//--------------------------------------------------------------------------

private var wkid:int = 4326;
private var _tileInfo:TileInfo = new TileInfo(); // see buildTileInfo()
private var _url:String = new String();
//private var _wmsLayer:String = new String();

//--------------------------------------------------------------------------
//
// Overridden properties
// fullExtent()
// initialExtent()
// spatialReference()
// tileInfo()
// units()
//
//--------------------------------------------------------------------------

//----------------------------------
// fullExtent
// - required to calculate the tiles to use
//----------------------------------

override public function get fullExtent():Extent
{
return new Extent(-180, -90, 180, 90, new SpatialReference(4326));
//return new Extent(65.94,18.84,137.74,62.85, new SpatialReference(4326));
}

//----------------------------------
// initialExtent
// - needed if Map doesn't have an extent
//----------------------------------

override public function get initialExtent():Extent
{
return new Extent(-124.731422,24.955967,-66.969849, 49.371735,new SpatialReference(4326));
//return new Extent(112.48,47.77,112.60,47.97, new SpatialReference(4326));
}

//----------------------------------
// spatialReference
// - needed if Map doesn't have a spatialReference
//----------------------------------

override public function get spatialReference():SpatialReference
{
return new SpatialReference(4326);
}

//----------------------------------
// tileInfo
//----------------------------------

override public function get tileInfo():TileInfo
{
return _tileInfo;
}

//----------------------------------
// units
// - needed if Map doesn't have it set
//----------------------------------

override public function get units():String
{
return "esriDecimalDegrees";
}

//--------------------------------------------------------------------------
//
// Overridden methods
// getTileURL(level:Number, row:Number, col:Number):URLRequest
//
//--------------------------------------------------------------------------

override protected function getTileURL(level:Number, row:Number, col:Number):URLRequest
{
var url:String ;
url = _url + "&X=" + col.toString() + "&Y=" + row.toString()+ "&L="+ level.toString();
return new URLRequest(url) ;
}

//--------------------------------------------------------------------------
//
// Private Methods
//
//--------------------------------------------------------------------------

private function buildTileInfo():void
{
_tileInfo.height = 256;
_tileInfo.width = 256;
_tileInfo.origin = new MapPoint(-180, 90);
_tileInfo.spatialReference = new SpatialReference(4326);
_tileInfo.lods = [
//new LOD(0, 1.40625, 590995197.1416691),
new LOD(1, 0.703125, 295497598.5708346),
new LOD(2, 0.3515625, 147748799.2854173),
new LOD(3, 0.17578125, 73874399.64270864),
new LOD(4, 0.087890625, 36937199.82135432),
new LOD(5, 0.0439453125, 18468599.91067716),
new LOD(6, 0.02197265625, 9234299.95533858),

new LOD(7, 0.010986328125, 4617149.97766929),
new LOD(8, 0.0054931640625, 2308574.98883465),
new LOD(9, 0.00274658203124999, 1154287.49441732),
new LOD(10, 0.001373291015625, 577143.747208662),
new LOD(11, 0.0006866455078125, 288571.873604331),
new LOD(12, 0.000343322753906249, 144285.936802165),
new LOD(13, 0.000171661376953125, 72142.9684010827),
new LOD(14, 0.0000858306884765626, 36071.4842005414),
new LOD(15, 0.0000429153442382813, 18035.7421002707),
new LOD(16, 0.0000214576721191406, 9017.87105013534),
];
}

private function padString(text:String, size:int, ch:String):String
{
while (text.length < size)
{
text = ch + text;
}
return text;
}
public function set url(val:String):void
{
this._url = val;
}
}
}

前台页面

xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
minWidth="955"
minHeight="600"
creationComplete="init()" xmlns:esri="http://www.esri.com/2008/ags">

import ext.SXGeoTileLayer;
private function init():void{
var wmslayer:SXGeoTileLayer=new SXGeoTileLayer();
wmslayer.url=" http://tile0.tianditu.com/DataServer?T=A0610_ImgAnno";
map.addLayer(wmslayer);
var wmslayer1:SXGeoTileLayer=new SXGeoTileLayer();
wmslayer1.url=" http://tile0.tianditu.com/DataServer?T=sbsm0210";
map.addLayer(wmslayer1);
}
]]>