arcgis for android 实现绘图功能

一：实现绘图功能的思路

1：首先需要一个点击地图的一个监听函数，可以实现点击地图画点、线、面。arcgis 提供一个MapOnTouchListener类。

2：创建点、线、面对象，arcgis提供的类有Point，Polygon，Line

3：设置样式，不管是点、线、面都有自己的样式。arcgis提供了 SimpleLineSymbol （线样式类）SimpleMarkerSymbol（点样式类）  SimpleFillSymbol（面样式类）

4：创建一个绘画的图层，GraphicsLayer

5：将绘画图层添加到地图上。

二:实现代码

1：创建一个类继承MapOnTouchListener用来监听地图的点击 

public class MapTouchListener extends MapOnTouchListener {
        /**
	 * 单击地图
	 */
	public boolean onSingleTap(MotionEvent point) {
        }
}

2：创建点、线、面对象

//屏幕坐标转化成空间坐标
Point mapPoint = map.toMapPoint(point.getX(),point.getY());

3：创建样式

	//设置点、线、面的样式
    private void initSymbols(){
    	markerSymbol = new SimpleMarkerSymbol(Color.BLUE,10,STYLE.CIRCLE);
    	lineSymbol =  new SimpleLineSymbol(Color.BLACK, 1, SimpleLineSymbol.STYLE.SOLID);
    	fillSymbol = new SimpleFillSymbol(Color.BLACK, SimpleFillSymbol.STYLE.SOLID);
    	fillSymbol.setAlpha(33);//设置的透明度
    } 

4：创建一个绘画图层

	   //创建绘图图层 对象
	   drawLayer = new GraphicsLayer();
	   mMapView.addLayer(drawLayer);

5：添加到地图上(这一定要加上，否则地图的监听事件无法实现)

  //绑定触摸事件监听器
	  mapTouchListener=new MapTouchListener(EarthquakeActivity.this,mMapView);
	  mapTouchListener.setLayer(drawLayer);
      mMapView.setOnTouchListener(mapTouchListener);

6：完成代码

package cn.zzu.Graphic;

import java.text.DecimalFormat;
import java.util.ArrayList;

import android.content.Context;
import android.graphics.Color;
import android.view.MotionEvent;
import android.widget.Toast;

import cn.zzu.Global.Variable;
import cn.zzu.Query.MyIdentifyTask;

import com.esri.android.map.GraphicsLayer;
import com.esri.android.map.MapOnTouchListener;
import com.esri.android.map.MapView;
import com.esri.core.geometry.Envelope;
import com.esri.core.geometry.Geometry;
import com.esri.core.geometry.Geometry.Type;
import com.esri.core.geometry.GeometryEngine;
import com.esri.core.geometry.Line;
import com.esri.core.geometry.MultiPath;
import com.esri.core.geometry.Point;
import com.esri.core.geometry.Polygon;
import com.esri.core.geometry.Polyline;
import com.esri.core.geometry.SpatialReference;
import com.esri.core.map.Graphic;
import com.esri.core.symbol.SimpleFillSymbol;
import com.esri.core.symbol.SimpleLineSymbol;
import com.esri.core.symbol.SimpleMarkerSymbol;
import com.esri.core.symbol.SimpleMarkerSymbol.STYLE;
import com.esri.core.tasks.identify.IdentifyParameters;

public class MapTouchListener extends MapOnTouchListener {
	private Context context;//上下文
	private MapView map;//地图对象
	private GraphicsLayer graphicsLayer;//画图图层
	private Geometry.Type geoType = null;//绘图的对象
	private Point endPonit = null;
	private Polygon polygon;
	private Polygon webPolygon;
	private SimpleLineSymbol lineSymbol;  
	private SimpleMarkerSymbol markerSymbol;  
	private SimpleFillSymbol fillSymbol;
	private ArrayList points=null;//记录全部点
	private IdentifyParameters params;
	public MapTouchListener(Context context, MapView map) {		
		super(context, map);
		this.context = context;
		this.map = map;
		//样式初始化
		initSymbols();
	}
	
	// 根据用户选择设置当前绘制的几何图形类型
	public void setDrawType(Geometry.Type geotype)
	{
		this.geoType=geotype;
		//将上一次绘图的图形删除
		graphicsLayer.removeAll();
		endPonit = null;
		if(geoType == Geometry.Type.POLYGON)
			points=new ArrayList();
	}
	/**
	 * 判断是否量测
	 * @param measure
	 */
	public void setMeasure(boolean measure){
		if(geoType == Geometry.Type.POLYLINE)
			Variable.measureLength = measure;
		if(geoType == Geometry.Type.POLYGON)
			Variable.measureArea = measure;
	}
	/**
	 * 
	 * 创建画图图层
	 * @param drawLayer
	 */
	public void setLayer(GraphicsLayer drawLayer){
		this.graphicsLayer=drawLayer;
	}
	//设置点、线、面的样式
    private void initSymbols(){
    	markerSymbol = new SimpleMarkerSymbol(Color.BLUE,10,STYLE.CIRCLE);
    	lineSymbol =  new SimpleLineSymbol(Color.BLACK, 1, SimpleLineSymbol.STYLE.SOLID);
    	fillSymbol = new SimpleFillSymbol(Color.BLACK, SimpleFillSymbol.STYLE.SOLID);
    	fillSymbol.setAlpha(33);//设置的透明度
    } 
    
    public void setQueryParams(){
    	//实例化对象，并且给实现初始化相应的值
    	params = new IdentifyParameters();//创建查询的对象
    	params.setTolerance(20);//设置识别的容差
    	params.setDPI(98);//设置自分辨率
    	params.setLayers(new int[]{0,1,2,3,6});//设置识别的图层
    	params.setLayerMode(IdentifyParameters.ALL_LAYERS);//设置模式为识别服务上所有的图层
    }

	/**
	 * 单击地图
	 */
	public boolean onSingleTap(MotionEvent point) {
		//屏幕坐标转化成空间坐标
		Point mapPoint = map.toMapPoint(point.getX(),point.getY());
		if(Variable.singleQuery&&geoType ==null){
			params.setGeometry(mapPoint);
		    params.setSpatialReference(map.getSpatialReference());    // 设置坐标系                                         
		    params.setMapHeight(map.getHeight());
		    params.setMapWidth(map.getWidth());
		    Envelope env = new Envelope();
		    map.getExtent().queryEnvelope(env);
		    params.setMapExtent(env);
		      //我们自己扩展的异步类
		    MyIdentifyTask mTask = new MyIdentifyTask(context,map,mapPoint);
		    mTask.execute(params);//执行异步操作并传递所需的参数    
		}
		
		if(geoType == Geometry.Type.POLYGON)
			points.add(mapPoint);//将当前点加入点集合中
		if(geoType == null)
			return true;
		if(geoType == Geometry.Type.POINT){
			//画点
			Graphic graphic = new Graphic(mapPoint,markerSymbol);
			graphicsLayer.addGraphic(graphic);
		}else{
			if(endPonit==null){
				//线或者面的第一个点
				Graphic graphic = new Graphic(mapPoint,markerSymbol);
				graphicsLayer.addGraphic(graphic);
			}else{
				//画点
				Graphic graphic = new Graphic(mapPoint,markerSymbol);
				graphicsLayer.addGraphic(graphic);
				//两点连线
				Line line = new Line() ;
				line.setStart(endPonit);//起始点 
				line.setEnd(mapPoint);//终止点
				
				//画折线
				if(geoType == Geometry.Type.POLYLINE){
					Polyline polyline = new Polyline(); 
					polyline.addSegment(line, true);  
		            Graphic iGraphic=new Graphic(polyline,lineSymbol); 
		            graphicsLayer.addGraphic(iGraphic);
		            if(Variable.measureLength)
		            	measure(endPonit,mapPoint,geoType);
				}
				if(geoType == Geometry.Type.POLYGON){
					graphicsLayer.removeAll();
					  //画面
				      if(polygon==null){  
		                  polygon=new Polygon(); 
		                  webPolygon=new Polygon();
		              }  
				      Polygon polygon = new Polygon();  
				      Point startPoint = null;  
			          Point endPoint = null;  	
			          // 绘制完整的多边形  
			           for(int i=1;i1000){
				mathLength=mathLength/1000;
				String format = new DecimalFormat("0.00").format(mathLength);//保留小数点后两位
				length = format+"公里";
			}else{
				String format = new DecimalFormat("0.00").format(mathLength);//保留小数点后两位
				length = format+"米";
			}
			Toast.makeText(context, "距离:"+length, Toast.LENGTH_SHORT).show();
		}
		
		if(geoType == Geometry.Type.POLYGON ){ 
			Polygon polygon = new Polygon();  	  
            Point startPoint = null;  
            Point endPoint = null;  
            // 绘制完整的多边形  
            for(int i=1;i1000000){
				mathArea2D=mathArea2D/1000000;
				String format = new DecimalFormat("0.00").format(mathArea2D);//保留小数点后两位
				Area = format+"平方公里";
			}else{
				String format = new DecimalFormat("0.00").format(mathArea2D);//保留小数点后两位
				Area = format+"平方米";
			}
			Toast.makeText(context, "面积:"+Area, Toast.LENGTH_SHORT).show();
		}
		
	}

}