顯示我的位置

本例說明如何啟用「我的位置」圖層,並示範如何使用「我的位置」按鈕在地圖上顯示裝置的目前位置 (以藍點表示)。

詳情請參閱說明文件

開始使用

請務必先設定開發環境,再試用程式碼範例。詳情請參閱「Maps SDK for Android 程式碼範例」一文。

查看程式碼

Kotlin

   class MyLocationDemoActivity : AppCompatActivity(),     OnMyLocationButtonClickListener,     OnMyLocationClickListener, OnMapReadyCallback,     OnRequestPermissionsResultCallback {     /**      * Flag indicating whether a requested permission has been denied after returning in      * [.onRequestPermissionsResult].      */     private var permissionDenied = false     private lateinit var map: GoogleMap     override fun onCreate(savedInstanceState: Bundle?) {         super.onCreate(savedInstanceState)         setContentView(R.layout.my_location_demo)         val mapFragment =             supportFragmentManager.findFragmentById(R.id.map) as SupportMapFragment?         mapFragment?.getMapAsync(this)     }      override fun onMapReady(googleMap: GoogleMap) {         map = googleMap         googleMap.setOnMyLocationButtonClickListener(this)         googleMap.setOnMyLocationClickListener(this)         enableMyLocation()     }      /**      * Enables the My Location layer if the fine location permission has been granted.      */     @SuppressLint("MissingPermission")     private fun enableMyLocation() {          // 1. Check if permissions are granted, if so, enable the my location layer         if (ContextCompat.checkSelfPermission(                 this,                 Manifest.permission.ACCESS_FINE_LOCATION             ) == PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(                 this,                 Manifest.permission.ACCESS_COARSE_LOCATION             ) == PackageManager.PERMISSION_GRANTED         ) {             map.isMyLocationEnabled = true             return         }          // 2. If if a permission rationale dialog should be shown         if (ActivityCompat.shouldShowRequestPermissionRationale(                 this,                 Manifest.permission.ACCESS_FINE_LOCATION             ) || ActivityCompat.shouldShowRequestPermissionRationale(                 this,                 Manifest.permission.ACCESS_COARSE_LOCATION             )         ) {             PermissionUtils.RationaleDialog.newInstance(                 LOCATION_PERMISSION_REQUEST_CODE, true             ).show(supportFragmentManager, "dialog")             return         }          // 3. Otherwise, request permission         ActivityCompat.requestPermissions(             this,             arrayOf(                 Manifest.permission.ACCESS_FINE_LOCATION,                 Manifest.permission.ACCESS_COARSE_LOCATION             ),             LOCATION_PERMISSION_REQUEST_CODE         )     }      override fun onMyLocationButtonClick(): Boolean {         Toast.makeText(this, "MyLocation button clicked", Toast.LENGTH_SHORT)             .show()         // Return false so that we don't consume the event and the default behavior still occurs         // (the camera animates to the user's current position).         return false     }      override fun onMyLocationClick(location: Location) {         Toast.makeText(this, "Current location:\n$location", Toast.LENGTH_LONG)             .show()     }      override fun onRequestPermissionsResult(         requestCode: Int,         permissions: Array<String>,         grantResults: IntArray     ) {         if (requestCode != LOCATION_PERMISSION_REQUEST_CODE) {             super.onRequestPermissionsResult(                 requestCode,                 permissions,                 grantResults             )             return         }          if (isPermissionGranted(                 permissions,                 grantResults,                 Manifest.permission.ACCESS_FINE_LOCATION             ) || isPermissionGranted(                 permissions,                 grantResults,                 Manifest.permission.ACCESS_COARSE_LOCATION             )         ) {             // Enable the my location layer if the permission has been granted.             enableMyLocation()         } else {             // Permission was denied. Display an error message             // ...         }     }      override fun onResumeFragments() {         super.onResumeFragments()         if (permissionDenied) {             // Permission was not granted, display error dialog.             showMissingPermissionError()             permissionDenied = false         }     }      /**      * Displays a dialog with error message explaining that the location permission is missing.      */     private fun showMissingPermissionError() {         newInstance(true).show(supportFragmentManager, "dialog")     }      companion object {         /**          * Request code for location permission request.          *          * @see .onRequestPermissionsResult          */         private const val LOCATION_PERMISSION_REQUEST_CODE = 1     } }        

Java

  public class MyLocationDemoActivity extends AppCompatActivity     implements     OnMyLocationButtonClickListener,     OnMyLocationClickListener,     OnMapReadyCallback,     ActivityCompat.OnRequestPermissionsResultCallback {      /**      * Request code for location permission request.      *      * @see #onRequestPermissionsResult(int, String[], int[])      */     private static final int LOCATION_PERMISSION_REQUEST_CODE = 1;      /**      * Flag indicating whether a requested permission has been denied after returning in {@link      * #onRequestPermissionsResult(int, String[], int[])}.      */     private boolean permissionDenied = false;      private GoogleMap map;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.my_location_demo);          SupportMapFragment mapFragment =             (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);         mapFragment.getMapAsync(this);     }      @Override     public void onMapReady(@NonNull GoogleMap googleMap) {         map = googleMap;         map.setOnMyLocationButtonClickListener(this);         map.setOnMyLocationClickListener(this);         enableMyLocation();     }      /**      * Enables the My Location layer if the fine location permission has been granted.      */     @SuppressLint("MissingPermission")     private void enableMyLocation() {         // 1. Check if permissions are granted, if so, enable the my location layer         if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)             == PackageManager.PERMISSION_GRANTED             || ContextCompat.checkSelfPermission(this, permission.ACCESS_COARSE_LOCATION)             == PackageManager.PERMISSION_GRANTED) {             map.setMyLocationEnabled(true);             return;         }          // 2. Otherwise, request location permissions from the user.         PermissionUtils.requestLocationPermissions(this, LOCATION_PERMISSION_REQUEST_CODE, true);     }      @Override     public boolean onMyLocationButtonClick() {         Toast.makeText(this, "MyLocation button clicked", Toast.LENGTH_SHORT).show();         // Return false so that we don't consume the event and the default behavior still occurs         // (the camera animates to the user's current position).         return false;     }      @Override     public void onMyLocationClick(@NonNull Location location) {         Toast.makeText(this, "Current location:\n" + location, Toast.LENGTH_LONG).show();     }      @Override     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,         @NonNull int[] grantResults) {         if (requestCode != LOCATION_PERMISSION_REQUEST_CODE) {             super.onRequestPermissionsResult(requestCode, permissions, grantResults);             return;         }          if (PermissionUtils.isPermissionGranted(permissions, grantResults,             Manifest.permission.ACCESS_FINE_LOCATION) || PermissionUtils             .isPermissionGranted(permissions, grantResults,                 Manifest.permission.ACCESS_COARSE_LOCATION)) {             // Enable the my location layer if the permission has been granted.             enableMyLocation();         } else {             // Permission was denied. Display an error message             // ...         }     }      @Override     protected void onResumeFragments() {         super.onResumeFragments();         if (permissionDenied) {             // Permission was not granted, display error dialog.             showMissingPermissionError();             permissionDenied = false;         }     }      /**      * Displays a dialog with error message explaining that the location permission is missing.      */     private void showMissingPermissionError() {         PermissionUtils.PermissionDeniedDialog             .newInstance(true).show(getSupportFragmentManager(), "dialog");     }  }        

複製並執行範例

需要使用 Git 才能在本機執行這個範例。下列指令會複製範例應用程式存放區。

git clone [email protected]:googlemaps-samples/android-samples.git

將範例專案匯入 Android Studio:

  1. 在 Android Studio 中,選取「File」(檔案) >「New」(新增) >「Import Project」(匯入專案)
  2. 前往您儲存存放區的位置,然後選取 Kotlin 或 Java 的專案目錄:

    • KotlinPATH-REPO/android-samples/ApiDemos/kotlin
    • JavaPATH-REPO/android-samples/ApiDemos/java
  3. 選取「Open」(開啟)。Android Studio 會使用 Gradle 建構工具來建立您的專案。
  4. 在與專案的 local.properties 檔案相同的目錄中,建立空白的 secrets.properties 檔案。詳情請參閱「將 API 金鑰加到專案」一文。
  5. 將下列字串加到 secrets.properties,並將 YOUR_API_KEY 換成您 API 金鑰的值:

    MAPS_API_KEY=YOUR_API_KEY
  6. 執行應用程式。