AndroidNote013.在百度地图上画出轨迹

接着上面的项目，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RemoveMyLocationOverlay mLocationOverlay = null; // 定位图层static View mPopView = null; // 点击mark时弹出的气泡ViewTraceServcie traceServcie;private ArrayList<Trace> myTraces = new ArrayList<Trace>();SharedPreferences sp;@Overridepublic 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Activitysuper.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() {@Overridepublic 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() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubIntent 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ItemizedOverlayDrawable 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);}}@Overrideprotected 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();}@Overrideprotected 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();}@Overrideprotected boolean isRouteDisplayed() {// TODO Auto-generated method stubreturn false;}}class OverItemT extends ItemizedOverlay<OverlayItem> {private List<OverlayItem> mGeoList = new ArrayList<OverlayItem>();private Drawable marker;private Context mContext;private ArrayList<Trace> traces = new ArrayList<Trace>();public OverItemT(Drawable marker, Context context, ArrayList<Trace> 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}}@Overridepublic 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mGeoListOverlayItem overLayItem = getItem(index); // 得到给定索引的itemString 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<Point> points = new ArrayList<Point>();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);}@Overrideprotected OverlayItem createItem(int i) {// TODO Auto-generated method stubreturn mGeoList.get(i);}@Overridepublic int size() {// TODO Auto-generated method stubreturn 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;}@Overridepublic 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：