接着上面的项目《Android访问webservice.客户端登录注册》http://www.linuxidc.com/Linux/2013-04/82747.htm，实现餐厅搜索，这个在吃客游记里就做过了，然后把餐厅显示出来，可以把该餐厅加入轨迹

关于轨迹点操作的前后台实现和之前的登录注册差不多，这里主要说一下，用户查看自己的轨迹时候，在手机

端的显示。

1.从服务器把轨迹点拿下来

2.地图上显示点

3.把点连成线

看代码吧，注释比较详细，关键的画线操作就在OverItemT这个类中。

package seu.android007.xin;

import java.util.ArrayList;

import java.util.List;

import com.baidu.mapapi.BMapManager;

import com.baidu.mapapi.GeoPoint;

import com.baidu.mapapi.ItemizedOverlay;

import com.baidu.mapapi.LocationListener;

import com.baidu.mapapi.MapActivity;

import com.baidu.mapapi.MapView;

import com.baidu.mapapi.MyLocationOverlay;

import com.baidu.mapapi.OverlayItem;

import com.baidu.mapapi.Projection;

import seu.android007.service.TraceServcie;

import seu.xin.entity.Trace;

import android.app.AlertDialog;

import android.content.Context;

import android.content.DialogInterface;

import android.content.Intent;

import android.content.SharedPreferences;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Path;

import android.graphics.Point;

import android.graphics.drawable.Drawable;

import android.location.Location;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup.LayoutParams;

import android.widget.Toast;

public class MyTrace extends MapActivity {

static MapView mMapView = null;

LocationListener mLocationListener = null;// onResume时注册此listener，onPause时需要Remove

MyLocationOverlay mLocationOverlay = null; // 定位图层

static View mPopView = null; // 点击mark时弹出的气泡View

TraceServcie traceServcie;

private ArrayList myTraces = new ArrayList();

SharedPreferences sp;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.my_trace);

traceServcie = new TraceServcie();

sp = this.getSharedPreferences("data", MODE_WORLD_READABLE);

int uid = sp.getInt("uid", 0);

myTraces = traceServcie.findTracesByUid(uid);

BMapApp app = (BMapApp) this.getApplication();

if (app.mBMapMan == null) {

app.mBMapMan = new BMapManager(getApplication());

app.mBMapMan.init(app.mStrKey, new BMapApp.MyGeneralListener());

}

app.mBMapMan.start();

// 如果使用地图SDK，请初始化地图Activity

super.initMapActivity(app.mBMapMan);

mMapView = (MapView) findViewById(R.id.bmapView);

mMapView.setBuiltInZoomControls(true);

// 设置在缩放动画过程中也显示overlay,默认为不绘制

mMapView.setDrawOverlayWhenZooming(true);

// 添加定位图层

mLocationOverlay = new MyLocationOverlay(this, mMapView);

mMapView.getOverlays().add(mLocationOverlay);

// 注册定位事件

mLocationListener = new LocationListener() {

@Override

public void onLocationChanged(Location location) {

if (location != null) {

GeoPoint pt = new GeoPoint(

(int) (location.getLatitude() * 1e6),

(int) (location.getLongitude() * 1e6));

mMapView.getController().animateTo(pt);

}

}

};

if (myTraces.size() == 0) {

System.out.println("轨迹为空，调转到MyActivityGroup");

AlertDialog.Builder builder = new AlertDialog.Builder(MyTrace.this);

builder.setTitle("提醒");

builder.setMessage("没有轨迹，请添加后再查看");

builder.setPositiveButton("确定",

new DialogInterface.OnClickListener() {

@Override

public void onClick(DialogInterface dialog, int which) {

// TODO Auto-generated method stub

Intent intent = new Intent();

intent.setClass(MyTrace.this, MyActivityGroup.class);

startActivity(intent);

MyTrace.this.finish();

}

});

builder.create().show();

} else {

System.out.println("获得点后添加到图层");

// 添加ItemizedOverlay

Drawable marker = getResources().getDrawable(R.drawable.iconmarka); // 得到需要标在地图上的资源

marker.setBounds(0, 0, marker.getIntrinsicWidth(),

marker.getIntrinsicHeight()); // 为maker定义位置和边界

mMapView.getOverlays().add(new OverItemT(marker, this, myTraces)); // 添加ItemizedOverlay实例到mMapView

// 创建点击mark时的弹出泡泡

mPopView = super.getLayoutInflater()

.inflate(R.layout.popview, null);

mMapView.addView(mPopView, new MapView.LayoutParams(

LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, null,

MapView.LayoutParams.TOP_LEFT));

mPopView.setVisibility(View.GONE);

}

}

@Override

protected void onPause() {

BMapApp app = (BMapApp) this.getApplication();

app.mBMapMan.getLocationManager().removeUpdates(mLocationListener);

mLocationOverlay.disableMyLocation();

mLocationOverlay.disableCompass(); // 关闭指南针

app.mBMapMan.stop();

super.onPause();

}

@Override

protected void onResume() {

BMapApp app = (BMapApp) this.getApplication();

// 注册定位事件，定位后将地图移动到定位点

app.mBMapMan.getLocationManager().requestLocationUpdates(

mLocationListener);

mLocationOverlay.enableMyLocation();

mLocationOverlay.enableCompass(); // 打开指南针

app.mBMapMan.start();

super.onResume();

}

@Override

protected boolean isRouteDisplayed() {

// TODO Auto-generated method stub

return false;

}

}

class OverItemT extends ItemizedOverlay {

private List mGeoList = new ArrayList();

private Drawable marker;

private Context mContext;

private ArrayList traces = new ArrayList();

public OverItemT(Drawable marker, Context context, ArrayList traces) {

super(boundCenterBottom(marker));

this.marker = marker;

this.mContext = context;

this.traces = traces;

// 用给定的经纬度构造GeoPoint，单位是微度 (度 * 1E6)

// 构造OverlayItem的三个参数依次为：item的位置，标题文本，文字片段

for (int i = 0; i < traces.size(); i++) {

int lat = new Integer(traces.get(i).getLatitude());

int lon = new Integer(traces.get(i).getLongitude());

String resName = traces.get(i).getResname();

GeoPoint p = new GeoPoint(lat, lon);

mGeoList.add(new OverlayItem(p, resName, i + resName));

populate(); // createItem(int)方法构造item。一旦有了数据，在调用其它方法前，首先调用这个方法

}

}

@Override

public void draw(Canvas canvas, MapView mapView, boolean shadow) {

// Projection接口用于屏幕像素坐标和经纬度坐标之间的变换

Projection projection = mapView.getProjection();

for (int index = size() - 1; index >= 0; index--) { // 遍历mGeoList

OverlayItem overLayItem = getItem(index); // 得到给定索引的item

String title = overLayItem.getTitle();

// 把经纬度变换到相对于MapView左上角的屏幕像素坐标

Point point = projection.toPixels(overLayItem.getPoint(), null);

// 可在此处添加您的绘制代码

Paint paintText = new Paint();

paintText.setColor(Color.BLUE);

paintText.setTextSize(15);

canvas.drawText(title, point.x - 30, point.y, paintText); // 绘制文本

}

super.draw(canvas, mapView, shadow);

// 调整一个drawable边界，使得(0，0)是这个drawable底部最后一行中心的一个像素

// 先所有点的经度转像素

ArrayList points = new ArrayList();

for (int i = 0; i < this.size(); i++) {

Point p = new Point();

OverlayItem overLayItem = getItem(i);

projection.toPixels(overLayItem.getPoint(), p);

points.add(p);

}

// 第二个画笔 画线

Paint paint = new Paint();

paint.setColor(Color.BLUE);

paint.setDither(true);

paint.setStyle(Paint.Style.STROKE);

paint.setStrokeJoin(Paint.Join.ROUND);

paint.setStrokeCap(Paint.Cap.ROUND);

paint.setStrokeWidth(4);

// 连接 所有点

Path path = new Path();

path.moveTo(points.get(0).x, points.get(0).y);

for (int i = 1; i < points.size(); i++) {

path.lineTo(points.get(i).x, points.get(i).y);

}

// 画出路径

canvas.drawPath(path, paint);

boundCenterBottom(marker);

}

@Override

protected OverlayItem createItem(int i) {

// TODO Auto-generated method stub

return mGeoList.get(i);

}

@Override

public int size() {

// TODO Auto-generated method stub

return mGeoList.size();

}

@Override

// 处理当点击事件

protected boolean onTap(int i) {

setFocus(mGeoList.get(i));

// 更新气泡位置,并使之显示

GeoPoint pt = mGeoList.get(i).getPoint();

MyTrace.mMapView.updateViewLayout(MyTrace.mPopView,

new MapView.LayoutParams(LayoutParams.WRAP_CONTENT,

LayoutParams.WRAP_CONTENT, pt,

MapView.LayoutParams.BOTTOM_CENTER));

MyTrace.mPopView.setVisibility(View.VISIBLE);

Toast.makeText(this.mContext, mGeoList.get(i).getSnippet(),

Toast.LENGTH_SHORT).show();

return true;

}

@Override

public boolean onTap(GeoPoint arg0, MapView arg1) {

// TODO Auto-generated method stub

// 消去弹出的气泡

MyTrace.mPopView.setVisibility(View.GONE);

return super.onTap(arg0, arg1);

}

}

运行的效果图：

原文来自 taoeer.topjavascript

百度地图根据已知坐标画点线，这两天用到的，在这里作个笔记，方便本身查阅！java

var map = new BMap.Map("map");

var point = new BMap.Point(116.404, 39.915);

map.centerAndZoom(point, 15);

map.enableScrollWheelZoom(); // 开启鼠标滚轮缩放

map.addControl(new BMap.ScaleControl()); // 添加比例尺控件

var pointStr = "104.038748,30.641821,104.047789,30.648128,104.063959,30.655336,104.067264,30.660307,104.067264,30.664438,104.064008,30.665316".split(",");

var pointArr = [];

for (var k = 0; k < pointStr.length; k += 2) {

pointArr.push({

lng: pointStr[k],

lat: pointStr[k + 1]

});

}

// 生成坐标点

var trackPoint = [];

for (var i = 0, j = pointArr.length; i < j; i++) {

trackPoint.push(new BMap.Point(pointArr[i].lng, pointArr[i].lat));

}

map.centerAndZoom(trackPoint[0], 15);

// 画线

var polyline = new BMap.Polyline(trackPoint, {

strokeColor: "#1869AD",

strokeWeight: 3,

strokeOpacity: 1

});

map.addOverlay(polyline);

// 配置图片

var size = new BMap.Size(26, 26);

var offset = new BMap.Size(0, -13);

var imageSize = new BMap.Size(26, 26);

var icon = new BMap.Icon("./express-position.png", size, {

imageSize: imageSize

});

// 画图标

for (var i = 0, j = trackPoint.length; i < j; i++) {

var marker = new BMap.Marker(trackPoint[i], {

icon: icon,

offset: offset

}); // 建立标注

map.addOverlay(marker);

}

//根据经纬极值计算绽开级别。 (从网上复制)

function getZoom(maxLng, minLng, maxLat, minLat) {

var zoom = ["50", "100", "200", "500", "1000", "2000", "5000", "10000", "20000", "25000", "50000", "100000", "200000", "500000", "1000000", "2000000"]; // 级别18到3。

var pointA = new BMap.Point(maxLng, maxLat); // 建立点坐标A

var pointB = new BMap.Point(minLng, minLat); // 建立点坐标B

var distance = map.getDistance(pointA, pointB).toFixed(1); //获取两点距离,保留小数点后两位

for (var i = 0, zoomLen = zoom.length; i < zoomLen; i++) {

if (zoom[i] - distance > 0) {

return 18 - i + 3; //之因此会多3，是由于地图范围经常是比例尺距离的10倍以上。因此级别会增长3。

}

}

}

// (从网上复制)

function setZoom(points) {

if (points.length > 0) {

var maxLng = points[0].lng;

var minLng = points[0].lng;

var maxLat = points[0].lat;

var minLat = points[0].lat;

var res;

for (var i = points.length - 1; i >= 0; i--) {

res = points[i];

if (res.lng > maxLng) maxLng = res.lng;

if (res.lng < minLng) minLng = res.lng;

if (res.lat > maxLat) maxLat = res.lat;

if (res.lat < minLat) minLat = res.lat;

}

var cenLng = (parseFloat(maxLng) + parseFloat(minLng)) / 2;

var cenLat = (parseFloat(maxLat) + parseFloat(minLat)) / 2;

var zoom = getZoom(maxLng, minLng, maxLat, minLat);

map.centerAndZoom(new BMap.Point(cenLng, cenLat), zoom);

} else {

//没有坐标，显示全中国

map.centerAndZoom(new BMap.Point(103.388611, 35.563611), 5);

}

}

setZoom(pointArr)