使用百度地图API实现驾车导航

前面两篇文章提到了使用百度API实现定位等功能，现在做了一个利用百度地图API实现驾车导航的功能，不仅仅是驾车导航，利用这套API还可以实现公交以及步行的导航功能，这里只介绍如何实现驾车导航，步行和公交大同小异。首先来看看最后实现效果：

        

进入应用后首先显示蓝色点为当前位置，可以输入目的地来形成导航线路（图1），也可以点选地图上任意点来形成导航线路（图2，3），选定点后，在地图上会标注红色定位点，点击开始导航按钮后便会形成最佳驾车线路。

接下来看看实现步骤：

首先是工程结构

          

其中libs下面是申请百度开发者后到地图API下下载Android的地图支持包并导入工程，这里不再细说。

然后是布局文件：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <LinearLayout        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:orientation="horizontal" >        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="目的地："            android:textSize="17sp" />        <EditText            android:id="@+id/et_destination"            android:layout_width="fill_parent"            android:hint="输入目的地名称或在地图上点选"            android:textSize="14sp"            android:layout_height="wrap_content" />    </LinearLayout>    <LinearLayout        android:layout_width="fill_parent"        android:layout_height="wrap_content" >        <Button            android:id="@+id/btn_navi"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:layout_weight="1"            android:text="开始导航" />        <Button            android:id="@+id/btn_clear"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:layout_weight="1"            android:text="清除路线" />    </LinearLayout>    <com.baidu.mapapi.MapView        android:id="@+id/bmapsView"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:clickable="true" /></LinearLayout>

然后是实现自定义的地图图层MyItemizedOverlay.java，这个类的作用是实现可点击地图图层的作用，点击地图后，便可以显示当前位置的经纬度，并可设置为目的地。

/** * 自定义图层 * @author Ryan */public class MyItemizedOverlay extends ItemizedOverlay<OverlayItem> {private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();private Context context;public MyItemizedOverlay(Context context,Drawable drawale) {super(boundCenterBottom(drawale));this.context=context;}@Overrideprotected OverlayItem createItem(int i) {return mOverlays.get(i);}@Overridepublic int size() {return mOverlays.size();}// 点击地图标注显示的内容@Overrideprotected boolean onTap(int index) {//这个方法的重写弹出信息等return true;}@Overridepublic void draw(Canvas canvas, MapView mapView, boolean shadow) {super.draw(canvas, mapView, shadow);}// Define a method in order to add new OverlayItems to our ArrayListpublic void addOverlay(OverlayItem overlay) {// add OverlayItemsmOverlays.add(overlay);populate();}//该方法的重写可以相应点击图标的区域内还是外@Overridepublic boolean onTap(GeoPoint p, MapView mapView) {final SharedPreferences sharedPreferences = context.getSharedPreferences("navigation_pre", Context.MODE_WORLD_WRITEABLE);//p获取的经纬度数据是整型变量,需要转换为float类型final float lat=p.getLatitudeE6();final float lon=p.getLongitudeE6();final MapView map = mapView;float latitude = sharedPreferences.getFloat("lat", 0);if (latitude == 0) {AlertDialog.Builder builder = new AlertDialog.Builder(this.context);builder.setTitle("设置目的地");builder.setMessage("设置选中的点为目的地吗？");builder.setPositiveButton("确定",new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {List<Overlay> overlays = map.getOverlays();GeoPoint gpoint = new GeoPoint((int)lat,(int)lon);OverlayItem overlayitem = new OverlayItem(gpoint, "title", "content");Drawable drawale = context.getResources().getDrawable(R.drawable.current_mark);MyItemizedOverlay iconOverlay = new MyItemizedOverlay(context,drawale);// 添加图层iconOverlay.addOverlay(overlayitem);overlays.add(iconOverlay);map.getController().animateTo(gpoint);Editor editor = sharedPreferences.edit();editor.putFloat("lat", lat);editor.putFloat("lon", lon);editor.commit();Toast.makeText(context, "纬度:"+lat / 1E6+"\n经度:"+lon / 1E6, Toast.LENGTH_SHORT).show();}});builder.setNegativeButton("取消", null);builder.create().show();}else {//AlertDialog.Builder builder = new AlertDialog.Builder(this.context);//builder.setTitle("设置目的地");//builder.setMessage("已经设置过线路，请先点击清除路线按钮清除当前路线");//builder.setNegativeButton("确定", null);//builder.create().show();Toast.makeText(context, "已经设置过线路，请先点击清除路线按钮清除当前路线",Toast.LENGTH_SHORT).show();}return super.onTap(p, mapView);}}

最后是主Activity实现类，注释中有详细说明：

public class NavigationDemoActivity extends MapActivity {//Map keyprivate String mMapKey = "你的MapKey，到百度开发者官网申请";private EditText destinationEditText = null;private Button startNaviButton = null;private Button clearButton = null;private MapView mapView = null;private BMapManager mMapManager = null;private MyLocationOverlay myLocationOverlay = null;//onResume时注册此listener，onPause时需要Remove,注意此listener不是Android自带的，是百度API中的private LocationListener locationListener = null;//搜索模块private MKSearch searchModel = null;private GeoPoint pt = null;private SharedPreferences sharedPreferences;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        requestWindowFeature(Window.FEATURE_NO_TITLE);        setContentView(R.layout.main);        //弹出使用说明对话框        showIntroduceDialog();                sharedPreferences = this.getSharedPreferences("navigation_pre", Context.MODE_WORLD_WRITEABLE);        destinationEditText = (EditText) this.findViewById(R.id.et_destination);        startNaviButton = (Button) this.findViewById(R.id.btn_navi);        clearButton = (Button) this.findViewById(R.id.btn_clear);                //初始化地图管理器        mMapManager = new BMapManager(getApplication());        mMapManager.init(mMapKey, new MyGeneralListener());        super.initMapActivity(mMapManager);                mapView = (MapView) this.findViewById(R.id.bmapsView);        //设置启用内置的缩放控件        mapView.setBuiltInZoomControls(true);          //设置在缩放动画过程中也显示overlay,默认为不绘制//        mapView.setDrawOverlayWhenZooming(true);        //设置初始化地图的缩放级别        mapView.getController().setZoom(16);        mapView.setClickable(true);                //获取当前位置层        myLocationOverlay = new MyLocationOverlay(this, mapView);        //将当前位置的层添加到地图底层中        mapView.getOverlays().add(myLocationOverlay);                //添加可点选地图获取目的地的层        addTapOverLay();                //注册定位事件        locationListener = new LocationListener(){@Overridepublic void onLocationChanged(Location location) {if (location != null){//生成GEO类型坐标并在地图上定位到该坐标标示的地点 pt = new GeoPoint((int)(location.getLatitude() * 1e6),(int)(location.getLongitude() * 1e6)); mapView.getController().animateTo(pt);}}        };                //初始化搜索模块        searchModel = new MKSearch();        //设置路线策略为最短距离        searchModel.setDrivingPolicy(MKSearch.ECAR_DIS_FIRST);        searchModel.init(mMapManager, new MKSearchListener() {//获取驾车路线回调方法@Overridepublic void onGetDrivingRouteResult(MKDrivingRouteResult res, int error) {// 错误号可参考MKEvent中的定义if (error != 0 || res == null) {Toast.makeText(NavigationDemoActivity.this, "抱歉，未找到结果", Toast.LENGTH_SHORT).show();return;}RouteOverlay routeOverlay = new RouteOverlay(NavigationDemoActivity.this, mapView);    // 此处仅展示一个方案作为示例MKRoute route = res.getPlan(0).getRoute(0);int distanceM = route.getDistance();String distanceKm = String.valueOf(distanceM / 1000) +"."+String.valueOf(distanceM % 1000);System.out.println("距离:"+distanceKm+"公里---节点数量:"+route.getNumSteps());for (int i = 0; i < route.getNumSteps(); i++) {MKStep step = route.getStep(i);System.out.println("节点信息："+step.getContent());System.out.println("经度："+step.getPoint().getLongitudeE6() / 1E6 +" 纬度："+step.getPoint().getLatitudeE6() / 1E6);}    routeOverlay.setData(route);    mapView.getOverlays().clear();    mapView.getOverlays().add(routeOverlay);    mapView.invalidate();    mapView.getController().animateTo(res.getStart().pt);}//以下两种方式和上面的驾车方案实现方法一样@Overridepublic void onGetWalkingRouteResult(MKWalkingRouteResult res, int error) {//获取步行路线}@Overridepublic void onGetTransitRouteResult(MKTransitRouteResult arg0, int arg1) {//获取公交线路}@Overridepublic void onGetBusDetailResult(MKBusLineResult arg0, int arg1) {}@Overridepublic void onGetAddrResult(MKAddrInfo arg0, int arg1) {}@Overridepublic void onGetSuggestionResult(MKSuggestionResult arg0, int arg1) {}@Overridepublic void onGetPoiResult(MKPoiResult arg0, int arg1, int arg2) {}});                startNaviButton.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {String destination = destinationEditText.getText().toString();//设置起始地（当前位置）MKPlanNode startNode = new MKPlanNode();startNode.pt = pt;//设置目的地MKPlanNode endNode = new MKPlanNode(); float lat = sharedPreferences.getFloat("lat", 0);float lon = sharedPreferences.getFloat("lon", 0);if (lat != 0 && lon != 0) {endNode.pt = new GeoPoint((int)lat,(int)lon);}else if (!destination.equals("")) {endNode.name = destination;}else {Toast.makeText(NavigationDemoActivity.this, "请输入或点选目的地",Toast.LENGTH_SHORT).show();return;}//展开搜索的城市String city = getResources().getString(R.string.beijing);searchModel.drivingSearch(city, startNode, city, endNode);//步行路线//searchModel.walkingSearch(city, startNode, city, endNode);//公交路线//searchModel.transitSearch(city, startNode, endNode);}});                //清除路线按钮事件        clearButton.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {List<Overlay> overlays = mapView.getOverlays();if (sharedPreferences.getFloat("lon", 0) != 0) {//移除顶层的路线图层overlays.remove(overlays.size() - 1);//添加用户当前位置图层overlays.add(myLocationOverlay);//地图更新定位到当前位置mapView.getController().animateTo(pt);//清除存储的经纬度信息Editor editor = sharedPreferences.edit();editor.clear();editor.commit();//添加可点选图层addTapOverLay();}else if (!destinationEditText.getText().toString().equals("")) {overlays.remove(overlays.size() - 1);overlays.add(myLocationOverlay);mapView.getController().animateTo(pt);addTapOverLay();}else {Toast.makeText(NavigationDemoActivity.this, "没有设置路线", Toast.LENGTH_SHORT).show();}}});    }        public void showIntroduceDialog(){    AlertDialog.Builder builder = new AlertDialog.Builder(this);    builder.setTitle("使用说明");    StringBuilder sb = new StringBuilder();    sb.append("1.地图中蓝色点为当前位置；\n\n");    sb.append("2.双指捏合或点击缩放按钮可以缩放地图；\n\n");    sb.append("3.在输入框中输入目的地或在地图上点选目的地；\n\n");    sb.append("4.选取目的地后点击按钮开始导航；\n\n");    sb.append("5.点击清除按钮取消本次导航路线；");    builder.setMessage(sb.toString());    builder.setNegativeButton("确定", null);    builder.create().show();    }        public void addTapOverLay(){    //以一副透明图片标示可点选图层，这里在地图上不显示出来，只提供可点选目的地功能    GeoPoint gpoint = new GeoPoint((int) (39.914714 * 1E6),(int) (116.404269 * 1E6));OverlayItem overlayitem = new OverlayItem(gpoint, "title", "content");Drawable drawale = getResources().getDrawable(R.drawable.current);MyItemizedOverlay iconOverlay = new MyItemizedOverlay(NavigationDemoActivity.this,drawale);// 添加图层iconOverlay.addOverlay(overlayitem);mapView.getOverlays().add(iconOverlay);    }        @Overrideprotected void onResume() {mMapManager.getLocationManager().requestLocationUpdates(locationListener);        myLocationOverlay.enableMyLocation();        myLocationOverlay.enableCompass(); // 打开指南针mMapManager.start();super.onResume();}        @Overrideprotected void onPause() {mMapManager.getLocationManager().removeUpdates(locationListener);myLocationOverlay.disableMyLocation();//显示当前位置myLocationOverlay.disableCompass(); // 关闭指南针mMapManager.stop();super.onPause();}@Overrideprotected boolean isRouteDisplayed() {// TODO Auto-generated method stubreturn false;}//按物理返回键退出应用时清空存储的经纬度信息@Overridepublic boolean dispatchKeyEvent(KeyEvent event) {if (event.getAction() == KeyEvent.ACTION_DOWN && event.getKeyCode() == KeyEvent.KEYCODE_BACK) {Editor editor = sharedPreferences.edit();editor.clear();editor.commit();}return super.dispatchKeyEvent(event);}// 常用事件监听，用来处理通常的网络错误，授权验证错误等class MyGeneralListener implements MKGeneralListener {@Overridepublic void onGetNetworkState(int iError) {Log.d("MyGeneralListener", "onGetNetworkState error is "+ iError);Toast.makeText(NavigationDemoActivity.this, "您的网络出错啦！",Toast.LENGTH_LONG).show();}@Overridepublic void onGetPermissionState(int iError) {Log.d("MyGeneralListener", "onGetPermissionState error is "+ iError);if (iError ==  MKEvent.ERROR_PERMISSION_DENIED) {// 授权Key错误：Toast.makeText(NavigationDemoActivity.this, "请在BMapApiDemoApp.java文件输入正确的授权Key！",Toast.LENGTH_LONG).show();}}}}

最后是配置文件：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.ericssonlabs"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk android:minSdkVersion="8" />    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission><uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission><uses-permission android:name="android.permission.INTERNET"></uses-permission><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission><uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>  <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission> <uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission><supports-screens android:largeScreens="true"    android:normalScreens="true" android:smallScreens="true"    android:resizeable="true" android:anyDensity="true"/><uses-sdk android:minSdkVersion="3"></uses-sdk>    <application        android:icon="@drawable/ic_launcher"        android:label="@string/app_name" >        <activity            android:name=".NavigationDemoActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

完成后直接运行就看到了最开始说的效果，有任何问题请给我留言交流。

对Android&IOS感兴趣的朋友可以加入我们的讨论QQ群，在这里，我们只讨论干货：

iOS群：220223507

Android群：282552849

欢迎关注我的新浪微博和我交流：@唐韧_Ryan