百度地图API之Marker的使用(Android)

最近在做一个APP，其中一个功能要在地图上显示酒店位置以及显示酒店的最低价格，要用到百度地图中的Overlay。

overlay有以下几种：

　　1）Overlay：它是所有覆盖物的抽象基类，所有的覆盖物均继承此类的方法，实现用户自定义图层显示；
      2）MyLocationOverlay：一个负责显示用户当前位置的Overlay； 
      3）ItemizedOverlay：它包含了一个OverlayItem列表，相当于一组分条的Overlay，通过继承此类，将一组兴趣点显示在地图上；
      4）PoiOverlay：本地搜索图层，提供某一特定地区的位置搜索服务，比如在北京市搜索“公园”，通过此图层将公园显示在地图上； 
      5）RouteOverlay：步行、驾车导航线路图层，将步行、驾车出行方案的路线及关键点显示在地图上；
      6）TransitOverlay：公交换乘线路图层，将某一特定地区的公交出行方案的路线及换乘位置显示在地图上。

在3.0以后版本中百度地图api中overlay改变比较大，我刚才所说的功能在3.0以前的版本是可以通过自定义的Overlay继承ItemizedOverlay来实现，在3.0以后的版本中已经找不到ItemizedOverlay了，已经用Marker代替。官方的android demo也没有关于marker

的事例，网上资料也较少，网页版较为简单，android只能自己摸索了。

我们先来看看最终做出的效果，如下图所示：

下面是具体实现：

1.页面activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <com.baidu.mapapi.map.MapView
        android:id="@+id/bmapView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

2.自定义Marker

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#fea531"
        android:gravity="center"
        android:orientation="horizontal" >
        <ImageView
            android:id="@+id/img_hotel_image"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:padding="2dip"
            android:scaleType="fitXY"
            android:src="@drawable/hotel_pic" />
        <TextView
            android:id="@+id/tv_hotel_price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="5dip"
            android:textColor="#ffffff"
            android:textSize="14dp" />
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal" >
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/custom_marker_triangle" />
    </LinearLayout>
</LinearLayout>

3.下面这段代码是关键，我们需要把自定义的view转换成Bitmap，MarkerOptions中的icon参数是Bitmap，自定义marker是很常用的，不明白百度为啥不搞个明显点方法，废了很多时间。

private Bitmap getViewBitmap(View addViewContent) {

        addViewContent.setDrawingCacheEnabled(true);

        addViewContent.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
        addViewContent.layout(0, 0, addViewContent.getMeasuredWidth(), addViewContent.getMeasuredHeight());

        addViewContent.buildDrawingCache();
        Bitmap cacheBitmap = addViewContent.getDrawingCache();
        Bitmap bitmap = Bitmap.createBitmap(cacheBitmap);

        return bitmap;
    }

4. 下面是Activity代码，

public class MainActivity extends Activity {

    private List<Hotel> mData;
    private SDKReceiver mReceiver;

    private MapView mMapView;
    private BaiduMap mBaiduMap;

    LocationClient mLocClient;
    private LocationMode mCurrentMode;
    public MyLocationListenner myListener = new MyLocationListenner();
    BitmapDescriptor mCurrentMarker;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        SDKInitializer.initialize(getApplicationContext());
        setContentView(R.layout.activity_main);

        IntentFilter iFilter = new IntentFilter();
        iFilter.addAction(SDKInitializer.SDK_BROADTCAST_ACTION_STRING_PERMISSION_CHECK_ERROR);
        iFilter.addAction(SDKInitializer.SDK_BROADCAST_ACTION_STRING_NETWORK_ERROR);
        mReceiver = new SDKReceiver();
        registerReceiver(mReceiver, iFilter);

        // 地图初始化
        mMapView = (MapView) findViewById(R.id.bmapView);
        mBaiduMap = mMapView.getMap();
        //initLocation();
        mBaiduMap.setOnMarkerClickListener(new OnMarkerClickListener() {
            public boolean onMarkerClick(final Marker marker) {
                // TO DO

                return true;
            }
        });
        mData = getData();
        generateMarker();

    }

    /**
     * Inits the location.
     */
    private void initLocation() {

        // 开启定位图层
        mBaiduMap.setMyLocationEnabled(true);
        // 定位初始化
        mLocClient = new LocationClient(this);
        mLocClient.registerLocationListener(myListener);
        LocationClientOption option = new LocationClientOption();
        option.setOpenGps(true);// 打开gps
        option.setCoorType("bd09ll"); // 设置坐标类型
        option.setScanSpan(1000);
        mLocClient.setLocOption(option);
        mLocClient.start();
    }

    /**
     * 定位SDK监听函数
     */
    public class MyLocationListenner implements BDLocationListener {
        @Override
        public void onReceiveLocation(BDLocation location) {
            // map view 销毁后不在处理新接收的位置
            if (location == null || mMapView == null)
                return;
            MyLocationData locData = new MyLocationData.Builder().accuracy(location.getRadius())
            // 此处设置开发者获取到的方向信息，顺时针0-360
                    .direction(100).latitude(location.getLatitude()).longitude(location.getLongitude()).build();
            mBaiduMap.setMyLocationData(locData);

            LatLng ll = new LatLng(location.getLatitude(), location.getLongitude());
            MapStatusUpdate u = MapStatusUpdateFactory.newLatLng(ll);
            mBaiduMap.animateMapStatus(u);

        }

        public void onReceivePoi(BDLocation poiLocation) {
        }
    }

    /**
     * The Class SDKReceiver.
     */
    public class SDKReceiver extends BroadcastReceiver {
        public void onReceive(Context context, Intent intent) {
            String s = intent.getAction();
            if (s.equals(SDKInitializer.SDK_BROADTCAST_ACTION_STRING_PERMISSION_CHECK_ERROR)) {
                Toast toast = Toast.makeText(context, "key 验证出错! 请在 AndroidManifest.xml 文件中检查 key 设置", Toast.LENGTH_SHORT);
                toast.setGravity(Gravity.CENTER, 0, 0);
                toast.show();
            } else if (s.equals(SDKInitializer.SDK_BROADCAST_ACTION_STRING_NETWORK_ERROR)) {
                Toast toast = Toast.makeText(context, "网络出错", Toast.LENGTH_SHORT);
                toast.setGravity(Gravity.CENTER, 0, 0);
                toast.show();
            }
        }
    }

    /**
     * Gets the view bitmap.
     *
     * @param addViewContent
     *            the add view content
     * @return the view bitmap
     */
    private Bitmap getViewBitmap(View addViewContent) {

        addViewContent.setDrawingCacheEnabled(true);

        addViewContent.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
        addViewContent.layout(0, 0, addViewContent.getMeasuredWidth(), addViewContent.getMeasuredHeight());

        addViewContent.buildDrawingCache();
        Bitmap cacheBitmap = addViewContent.getDrawingCache();
        Bitmap bitmap = Bitmap.createBitmap(cacheBitmap);

        return bitmap;
    }

    /**
     * Gets the data.
     *
     * @return the data
     */
    public List<Hotel> getData() {
        try {
            List<Hotel> resultList = new ArrayList<Hotel>();
            AssetManager manager = getApplicationContext().getAssets();
            InputStream file = manager.open("data.json");
            byte[] data = new byte[file.available()];
            file.read(data);
            file.close();
            String jsonStr = new String(data);
            JSONObject json = JSON.parseObject(jsonStr);
            String jsonText = json.getString("Output");

            return JSONArray.parseArray(jsonText.toString(), Hotel.class);

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }
    }

    public void generateMarker() {

        for (Iterator iterator = mData.iterator(); iterator.hasNext();) {
            Hotel hotel = (Hotel) iterator.next();
            LatLng ll = new LatLng(hotel.HotelLatitude, hotel.HotelLongitude);
            View view = LayoutInflater.from(getApplicationContext()).inflate(R.layout.custom_marker, null);

            // ImageView img_hotel_image=
            // (ImageView)view.findViewById(R.id.img_hotel_image);
            // new
            // DownloadImageTask(img_hotel_image).execute(hotel.getHotelImageUrl());

            TextView tv_hotel_price = (TextView) view.findViewById(R.id.tv_hotel_price);
            tv_hotel_price.setText(new StringBuilder().append(hotel.getHotelPrice()).append("￥起"));
            BitmapDescriptor markerIcon = BitmapDescriptorFactory.fromBitmap(getViewBitmap(view));

            Bundle bundle = new Bundle();
            bundle.putSerializable("HOTEL", hotel);

            OverlayOptions oo = new MarkerOptions().position(ll).icon(markerIcon).zIndex(9).draggable(true).extraInfo(bundle);
            mBaiduMap.addOverlay(oo);
        }

    }

    @Override
    protected void onPause() {
        mMapView.onPause();
        super.onPause();
    }

    @Override
    protected void onResume() {
        mMapView.onResume();
        super.onResume();
    }

    @Override
    protected void onDestroy() {
        // 退出时销毁定位
        mLocClient.stop();
        // 关闭定位图层
        mBaiduMap.setMyLocationEnabled(false);
        mMapView.onDestroy();
        mMapView = null;
        super.onDestroy();
    }

}

activity代码注释不多，有不明白的地方请自行下载官方Demo来研究。

代码下载地址 http://download.csdn.net/detail/showraining/9058193