数据挖掘概念与技术,亚冠半决赛时间,光电子快报
一：思路
注意：量测功能是在web墨卡托坐标系下实现，如果使用天地图（wgs-84坐标）做底图，不进行坐标转化会出现量测错误。
1：首先进行画线，画面。
2：量测
在距离量测的arcgis提供了line.calculatelength2d();来实现
在面积量测arcgis提供了polygon.calculatearea2d()来实现。
二：实现的具体方法
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/**
* 距离量测和面积量测
* @param startponit
* @param endponit
* @param geotype
*/
public void measure(point startponit,point endponit,geometry.type geotype){
point mspoint = (point) geometryengine.project(startponit ,map.getspatialreference(),spatialreference.create(102100));
point mepoint = (point) geometryengine.project(endponit ,map.getspatialreference(),spatialreference.create(102100));
//两点连线
line line = new line() ;
line.setstart(mepoint);//起始点
line.setend(mspoint);//终止点
if(geotype == geometry.type.polyline ){
//距离量测
double mathlength = line.calculatelength2d();
string length = null;
if(mathlength>1000){
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();
}
三：全部代码
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();
}
}
}
还需要在mapview中实现
//创建绘图图层 对象 drawlayer = new graphicslayer(); mmapview.addlayer(drawlayer); //绑定触摸事件监听器 maptouchlistener=new maptouchlistener(earthquakeactivity.this,mmapview); maptouchlistener.setlayer(drawlayer); mmapview.setontouchlistener(maptouchlistener);
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