進入應用後首先顯示藍色點為當前位置，可以輸入目的地來形成導航線路（圖1），也可以點選地圖上任意點來形成導航線路（圖2，3），選定點後，在地圖上會標註紅色定位點，點擊開始導航按鈕後便會形成最佳駕車線路。
接下來看看實現步驟：
首先是工程結構
其中libs下面是申請百度開發者後到地圖API下下載Android的地圖支持包並導入工程，這裡不再細說。
然後是佈局文件：
[html]
<?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="輸入目的地名稱或在地圖上點選"
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="開始導航" />
<Button
android:id="@+id/btn_clear"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="清除路線" />
</LinearLayout>
<com.baidu.mapapi.MapView
android:id="@+id/bmapsView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="true" />
</LinearLayout>
然後是實現自定義的地圖圖層MyItemizedOverlay.java，這個類的作用是實現可點擊地圖圖層的作用，點擊地圖後，便可以顯示當前位置的經緯度，並可設置為目的地。
[java]
/**
* 自定義圖層
* @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;
}
@Override
protected OverlayItem createItem(int i) {
return mOverlays.get(i);
}
@Override
public int size() {
return mOverlays.size();
}
// 點擊地圖標註顯示的內容
@Override
protected boolean onTap(int index) {
//這個方法的重寫彈出信息等
return true;
}
@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {
super.draw(canvas, mapView, shadow);
}
// Define a method in order to add new OverlayItems to our ArrayList
public void addOverlay(OverlayItem overlay) {
// add OverlayItems
mOverlays.add(overlay);
populate();
}
//該方法的重寫可以相應點擊圖標的區域內還是外
@Override
public boolean onTap(GeoPoint p, MapView mapView) {
final SharedPreferences sharedPreferences = context.getSharedPreferences("navigation_pre", Context.MODE_WORLD_WRITEABLE);
//p獲取的經緯度數據是整型變量,需要轉換為float類型
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("設置目的地");
builder.setMessage("設置選中的點為目的地嗎？");
builder.setPositiveButton("確定",new OnClickListener() {
@Override
public 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);
// 添加圖層
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, "緯度:"+lat / 1E6+"\n經度:"+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("設置目的地");
// builder.setMessage("已經設置過線路，請先點擊清除路線按鈕清除當前路線");
// builder.setNegativeButton("確定", null);
// builder.create().show();
Toast.makeText(context, "已經設置過線路，請先點擊清除路線按鈕清除當前路線",Toast.LENGTH_SHORT).show();
}
return super.onTap(p, mapView);
}
}
最後是主Activity實現類，註釋中有詳細說明：
[java]
public class NavigationDemoActivity extends MapActivity {
//Map key
private String mMapKey = "你的MapKey，到百度開發者官網申請";
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時註冊此listener，onPause時需要Remove,註意此listener不是Android自帶的，是百度API中的
private LocationListener locationListener = null;
//搜索模塊
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);
//彈出使用說明對話框
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);
//初始化地圖管理器
mMapManager = new BMapManager(getApplication());
mMapManager.init(mMapKey, new MyGeneralListener());
super.initMapActivity(mMapManager);
mapView = (MapView) this.findViewById(R.id.bmapsView);
//設置啟用內置的縮放控件
mapView.setBuiltInZoomControls(true);
//設置在縮放動畫過程中也顯示overlay,默認為不繪制
// mapView.setDrawOverlayWhenZooming(true);
//設置初始化地圖的縮放級別
mapView.getController().setZoom(16);
mapView.setClickable(true);
//獲取當前位置層
myLocationOverlay = new MyLocationOverlay(this, mapView);
//將當前位置的層添加到地圖底層中
mapView.getOverlays().add(myLocationOverlay);
//添加可點選地圖獲取目的地的層
addTapOverLay();
//註冊定位事件
locationListener = new LocationListener(){
@Override
public void onLocationChanged(Location location) {
if (location != null){
//生成GEO類型坐標並在地圖上定位到該坐標標示的地點
pt = new GeoPoint((int)(location.getLatitude() * 1e6),
(int)(location.getLongitude() * 1e6));
mapView.getController().animateTo(pt);
}
}
};
//初始化搜索模塊
searchModel = new MKSearch();
//設置路線策略為最短距離
searchModel.setDrivingPolicy(MKSearch.ECAR_DIS_FIRST);
searchModel.init(mMapManager, new MKSearchListener() {
//獲取駕車路線回調方法
@Override
public void onGetDrivingRouteResult(MKDrivingRouteResult res, int error) {
// 錯誤號可參考MKEvent中的定義
if (error != 0 || res == null) {
Toast.makeText(NavigationDemoActivity.this, "抱歉，未找到結果", Toast.LENGTH_SHORT).show();
return;
}
RouteOverlay routeOverlay = new RouteOverlay(NavigationDemoActivity.this, mapView);
// 此處僅展示一個方案作為示例
MKRoute route = res.getPlan(0).getRoute(0);
int distanceM = route.getDistance();
String distanceKm = String.valueOf(distanceM / 1000) +"."+String.valueOf(distanceM % 1000);
System.out.println("距離:"+distanceKm+"公裡—節點數量:"+route.getNumSteps());
for (int i = 0; i < route.getNumSteps(); i++) {
MKStep step = route.getStep(i);
System.out.println("節點信息："+step.getContent());
System.out.println("經度："+step.getPoint().getLongitudeE6() / 1E6 +" 緯度："+step.getPoint().getLatitudeE6() / 1E6);
}
routeOverlay.setData(route);
mapView.getOverlays().clear();
mapView.getOverlays().add(routeOverlay);
mapView.invalidate();
mapView.getController().animateTo(res.getStart().pt);
}
//以下兩種方式和上面的駕車方案實現方法一樣
@Override
public void onGetWalkingRouteResult(MKWalkingRouteResult res, int error) {
//獲取步行路線
}
@Override
public void onGetTransitRouteResult(MKTransitRouteResult arg0, int arg1) {
//獲取公交線路
}
@Override
public void onGetBusDetailResult(MKBusLineResult arg0, int arg1) {
}
@Override
public void onGetAddrResult(MKAddrInfo arg0, int arg1) {
}
@Override
public void onGetSuggestionResult(MKSuggestionResult arg0, int arg1) {
}
@Override
public void onGetPoiResult(MKPoiResult arg0, int arg1, int arg2) {
}
});
startNaviButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String destination = destinationEditText.getText().toString();
//設置起始地（當前位置）
MKPlanNode startNode = new MKPlanNode();
startNode.pt = pt;
//設置目的地
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, "請輸入或點選目的地",Toast.LENGTH_SHORT).show();
return;
}
//展開搜索的城市
String city = getResources().getString(R.string.beijing);
searchModel.drivingSearch(city, startNode, city, endNode);
//步行路線
// searchModel.walkingSearch(city, startNode, city, endNode);
//公交路線
// searchModel.transitSearch(city, startNode, endNode);
}
});
//清除路線按鈕事件
clearButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
List<Overlay> overlays = mapView.getOverlays();
if (sharedPreferences.getFloat("lon", 0) != 0) {
//移除頂層的路線圖層
overlays.remove(overlays.size() – 1);
//添加用戶當前位置圖層
overlays.add(myLocationOverlay);
//地圖更新定位到當前位置
mapView.getController().animateTo(pt);
//清除存儲的經緯度信息
Editor editor = sharedPreferences.edit();
editor.clear();
editor.commit();
//添加可點選圖層
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, "沒有設置路線", Toast.LENGTH_SHORT).show();
}
}
});
}
public void showIntroduceDialog(){
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("使用說明");
StringBuilder sb = new StringBuilder();
sb.append("1.地圖中藍色點為當前位置；\n\n");
sb.append("2.雙指捏合或點擊縮放按鈕可以縮放地圖；\n\n");
sb.append("3.在輸入框中輸入目的地或在地圖上點選目的地；\n\n");
sb.append("4.選取目的地後點擊按鈕開始導航；\n\n");
sb.append("5.點擊清除按鈕取消本次導航路線；");
builder.setMessage(sb.toString());
builder.setNegativeButton("確定", null);
builder.create().show();
}
public void addTapOverLay(){
//以一副透明圖片標示可點選圖層，這裡在地圖上不顯示出來，隻提供可點選目的地功能
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);
// 添加圖層
iconOverlay.addOverlay(overlayitem);
mapView.getOverlays().add(iconOverlay);
}
@Override
protected void onResume() {
mMapManager.getLocationManager().requestLocationUpdates(locationListener);
myLocationOverlay.enableMyLocation();
myLocationOverlay.enableCompass(); // 打開指南針
mMapManager.start();
super.onResume();
}
@Override
protected void onPause() {
mMapManager.getLocationManager().removeUpdates(locationListener);
myLocationOverlay.disableMyLocation();//顯示當前位置
myLocationOverlay.disableCompass(); // 關閉指南針
mMapManager.stop();
super.onPause();
}
@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
//按物理返回鍵退出應用時清空存儲的經緯度信息
@Override
public 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);
}
// 常用事件監聽，用來處理通常的網絡錯誤，授權驗證錯誤等
class MyGeneralListener implements MKGeneralListener {
@Override
public void onGetNetworkState(int iError) {
Log.d("MyGeneralListener", "onGetNetworkState error is "+ iError);
Toast.makeText(NavigationDemoActivity.this, "您的網絡出錯啦！",
Toast.LENGTH_LONG).show();
}
@Override
public void onGetPermissionState(int iError) {
Log.d("MyGeneralListener", "onGetPermissionState error is "+ iError);
if (iError == MKEvent.ERROR_PERMISSION_DENIED) {
// 授權Key錯誤：
Toast.makeText(NavigationDemoActivity.this,
"請在BMapApiDemoApp.java文件輸入正確的授權Key！",
Toast.LENGTH_LONG).show();
}
}
}
}
最後是配置文件：
[html]
<?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>