Android 開發過程中,有很多手勢操作都很讓人又愛又恨。一方面可以更便捷的體現更多功能,提升應用的體驗,一方面繁復多變的操作背后有著許多開發技巧和難題。這里分享一個長按地圖獲取位置信息的手勢。為了更明了,先上個展示效果:長按地圖某點顯示該點地理位置信息功能通過構造一個locationSelectOverlay類來定義該功能,在地圖上對長按手勢進行監聽,一旦有這個發生就調用getAddressFromServer()方法來顯示地址信息。在該工程中分別定義4個類longPressMap.java,locationSelectOverlay.java,popUpPanel.java,Constants.javalongPressMap.java 為顯示一個地圖類,通過實例化一個locationSelectOverlay類實現長按地圖顯示地理位置信息功能代碼如下://longPressMap 類繼承MapActivity對mapview資源進行管理public class longPressMap extends MapActivity {private MapView mMapView;locationSelectOverlay mSelectLay;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);//使用setContentView方法調用R.layout.activity_regeocoder布局文件,顯示地圖setContentView(R.layout.geocoder);//獲取地圖視圖的id,賦值給mMapView mMapView = ((MapView) findViewById(R.id.geocode_MapView));// 設置啟用內置的縮放控件mMapView.setBuiltInZoomControls(true); //實例化一個locationSelectOverlay類mSelectLay = new locationSelectOverlay(this, mMapView, new popUpPanel(this, mMapView));//將該功能加載到此地圖上,啟用長按地圖顯示該點地址信息的功能mMapView.getOverlays().add(mSelectLay);} }復制代碼locationSelectOverlay 示例代碼如下://locationSelectOverlay類繼承Overlay接口,實現OnGestureListener手勢監聽public class locationSelectOverlay extends Overlay implements OnGestureListener {public popUpPanel mTipPanel; //聲明一個彈出框對象GeoPoint mSelectPoint; //聲明一個地理坐標點對象MapView mMapView; //聲明一個地圖視圖對象Context mContext; //活動對象TextView mTipText=null; //聲明一個文本對象private static String nearbystr="";private GestureDetector gestureScanner; //聲明一個手勢監聽對象private Geocoder coder; //聲明一個逆地理編碼對象private String addressName=""; //聲明一個地址名稱字符串//長按地圖某點獲取信息的構造函數。public locationSelectOverlay(Activity context,MapView mapView,popUpPanel panel){this.mContext=context; this.mMapView=mapView;this.mTipPanel=panel; gestureScanner = new GestureDetector(this); //聲明一個手勢監聽對象coder = new Geocoder(context); //聲明一個逆地理編碼對象}//用Handler函數處理傳遞來的地址信息,顯示在文本框中private Handler mGeocoderHandler = new Handler(){public void handleMessage(Message msg){//如果有地址信息的消息發送過來,將文本框中設置為該地址信息if(msg.what == Constants.REOCODER_RESULT){if(mTipText!=null)mTipText.setText(addressName);}//如果顯示錯誤,則文本框中設置報錯信息else if(msg.what == Constants.ERROR){Toast.makeText(mContext, "獲取地址失敗,請重試", Toast.LENGTH_SHORT).show();removeTipPanel();}}};//顯示彈出窗口public boolean showTap(GeoPoint p) {View view = mTipPanel.getView();mMapView.removeView(view);//布局參數設置MapView.LayoutParams geoLP = new MapView.LayoutParams(MapView.LayoutParams.WRAP_CONTENT,MapView.LayoutParams.WRAP_CONTENT, p,MapView.LayoutParams.BOTTOM_CENTER);//彈出窗口的文本顯示mTipText = (TextView) view.findViewById(R.id.GeoName);mTipText.setText("正在加載地址...");mTipText.setOnClickListener(new OnClickListener() {public void onClick(View v) {}});//在地圖視圖上添加該彈出窗口視圖mMapView.addView(view, geoLP);return false;}//從經緯度坐標點獲取對應的地址信息public void getAddressFromServer(final GeoPoint nt,final Handler handler){//聲明一個線程new Thread(){public void run(){try {// 逆地理編碼getFromLocation()函數獲取該點對應的前3個地址信息List<Address> address = coder.getFromLocation((double)nt.getLatitudeE6()/1E6,(double)nt.getLongitudeE6()/1E6, 3);if (address != null) {//獲取第一個地址信息Address addres = address.get(0);addressName = "";if(addres.getAdminArea()!=null)addressName+=addres.getAdminArea();if(addres.getSubLocality()!=null)addressName += addres.getSubLocality();if(addres.getFeatureName()!=null)addressName += addres.getFeatureName();addressName += "附近";handler.sendMessage(Message.obtain(handler, Constants.REOCODER_RESULT));}} catch (AMapException e) {// TODO Auto-generated catch blockhandler.sendMessage(Message.obtain(handler, Constants.ERROR));}}}.start(); //線程啟動}//移走彈出窗口public void removeTipPanel(){ View view = mTipPanel.getView();mMapView.removeView(view);}//獲取手勢操作public boolean onTouchEvent(MotionEvent event, MapView mapView) {return gestureScanner.onTouchEvent(event);}@Overridepublic boolean onDown(MotionEvent e) {// TODO Auto-generated method stubreturn false;}@Overridepublic boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY) {// TODO Auto-generated method stubreturn false;}//長按地圖,彈出提示框,顯示該點地址信息@Overridepublic void onLongPress(MotionEvent e) {// TODO Auto-generated method stubint x = (int)e.getX();int y = (int)e.getY();mSelectPoint = mMapView.getProjection().fromPixels(x, y);//調用顯示提示框函數showTap(mSelectPoint);//調用從經緯度點獲取地址信息函數getAddressFromServer(mSelectPoint,mGeocoderHandler);}@Overridepublic boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,float distanceY) {// TODO Auto-generated method stubreturn false;}復制代碼pouUpPanel定義了彈出窗口類public class popUpPanel{private boolean isVisible = false;private MapView mMapView;private View popup;public popUpPanel(Activity paramActivity, MapView paramMapView){this.mMapView = paramMapView;ViewGroup localViewGroup = (ViewGroup)this.mMapView.getParent();//設置彈出的視圖是id為R.layout.activity_long_press_map的視圖this.popup = paramActivity.getLayoutInflater().inflate(R.layout.activity_long_press_map, localViewGroup, false);…復制代碼Constants定義了傳遞的常量對應的值，如public static finalint REOCODER_RESULT=3000; 表示逆地理編碼結果常量，public staticfinal int ERROR=1001; 表示出現錯誤常量。