(转载)ArcGIS Flex API配合LibertyGISI加载SHP文件

本文转载自《使用LibertyGIS在Flex中加载Shape数据》http://www.dancecoder.com/2012/255.html和《ArcGIS Flex API加载SHP文件》http://www.gisall.com/html/66/102766-4308.html

某些情况下，如果在WebGIS系统中能够加载本地Map数据，会给用户带来很大的方便。SHP是使用范围很广泛的数据格式，而且数据结构早已公开，已经存在很多能够对SHP文件进行读取操作的类库。我们今天借助LibertyGIS（http://www.libertyvanguard.com/，一个开源的Flex GIS Framework）来实现在浏览器端加载SHP数据。

首先来介绍下LibertyGIS，LibertyGIS是开源的shape数据展现框架（LibertyGIS is an open source flex mapping framework for displaying ShapeFiles），官网地址：http://code.google.com/p/liberty-gis/；该框架包括一个独立的Map对象（com.liberty.controls.Map）以及加载shape文件所需的shp文件相关对象（ com.liberty.files.dbf.DBF; com.liberty.files.shapefile.ShapeFile），此外，LibertyGIS还提供了一个图层对象DataLayer（com.liberty.core.DataLayer）和自己的MapEvent事件。使用LibertyGIS能够很容易的展现我们客户端的shp数据。

<?xml version="1.0" encoding="utf-8"?><s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark"   xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"   xmlns:local="*" xmlns:esri="http://www.esri.com/2008/ags"   xmlns:shapefile="com.liberty.files.shapefile.*"><fx:Script><![CDATA[import com.esri.ags.Graphic;import com.esri.ags.SpatialReference;import com.esri.ags.geometry.MapPoint;import com.esri.ags.geometry.Polygon;import com.esri.ags.geometry.Polyline;import com.esri.ags.utils.WebMercatorUtil;import com.liberty.files.shapefile.IShapeFileContent;import com.liberty.files.shapefile.ShapeFileRecord;import mx.collections.ArrayCollection;import mx.controls.Alert;private var sps:SimpleMarkerSymbol=new SimpleMarkerSymbol();private var sls:SimpleLineSymbol=new SimpleLineSymbol("solid");private var sfs:SimpleFillSymbol=new SimpleFillSymbol("solid",0xff0000,0.7,sls);private function loadShpData():void{shpFile.source="assets/data/cities.shp";}private function shpFileLoadComplete(event:Event):void{var graphics:ArrayCollection=new ArrayCollection();var records:Array=shpFile.records;for (var i:int=0; i < records.length; i++){var record:ShapeFileRecord=records[i];var content:IShapeFileContent=record.content;var points:Vector.<Number>=content.getPoints();switch(shpFile.type){case 1:{var mapPoint:MapPoint=new MapPoint(points[0], points[1],new SpatialReference(4326));if(map.spatialReference.wkid!=4326){mapPoint=WebMercatorUtil.geographicToWebMercator(mapPoint) as MapPoint;}var graphic:Graphic=new Graphic(mapPoint);graphic.symbol=sps;graphics.addItem(graphic);graphicsLayer.add(graphic);break;}case 3:{var pArrLine:Array=new Array();for(var j:Number=0;j<points.length;j+=2){var point:MapPoint=new MapPoint(points[j],points[j+1],new SpatialReference(4326));if(map.spatialReference.wkid!=4326){point=WebMercatorUtil.geographicToWebMercator(point) as MapPoint;}pArrLine.push(point);}var polyline:Polyline=new Polyline();polyline.addPath(pArrLine);var grPolyline:Graphic=new Graphic(polyline);grPolyline.symbol=sls;graphics.addItem(grPolyline);graphicsLayer.add(grPolyline);break;}case 5:{var pArrPolygon:Array=new Array();for(var k:Number=0;k<points.length-1;k+=2){var pPoint:MapPoint=new MapPoint(points[k],points[k+1],new SpatialReference(4326));if(map.spatialReference.wkid!=4326){pPoint=WebMercatorUtil.geographicToWebMercator(pPoint) as MapPoint;}pArrPolygon.push(pPoint);}var polygon:Polygon=new Polygon();polygon.addRing(pArrPolygon);var grPolygon:Graphic=new Graphic(polygon);grPolygon.symbol=sfs;graphics.addItem(grPolygon);graphicsLayer.add(grPolygon);break;}default:{Alert.show("LibertyGIS不支持您的数据格式！","提示");return;}}}graphicsLayer.graphicProvider=graphics;}private function onShapeFileProgress(event:ProgressEvent):void{progressBar.setProgress((event.bytesLoaded / event.bytesTotal) * 100, 100);progressBar.label=int(event.bytesLoaded / 1000).toString() + "K";}]]></fx:Script><fx:Declarations><shapefile:ShapeFile id="shpFile" complete="shpFileLoadComplete(event)" progress="onShapeFileProgress(event)"/></fx:Declarations><esri:Map id="map"><esri:ArcGISTiledMapServiceLayer url="http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer"/><esri:GraphicsLayer id="graphicsLayer"><esri:symbol><esri:SimpleMarkerSymbol color="0xff0000" size="5"><esri:outline><esri:SimpleLineSymbol color="0x000000"/></esri:outline></esri:SimpleMarkerSymbol></esri:symbol></esri:GraphicsLayer></esri:Map><mx:HBox width="100%" backgroundColor="0xff0000"><s:Button label="Load SHP Data" click="loadShpData()"/><mx:ProgressBar id="progressBar" minimum="0" maximum="100" mode="manual" color="0xFFFFFF"labelPlacement="right"/></mx:HBox></s:Application>

效果如下