Question

我正试图通过此Link在我的应用中使用Google地图但我无法在设备上看到地图

这是日志

10-04 16:12:16.631: E/AndroidRuntime(1023): FATAL EXCEPTION: main
10-04 16:12:16.631: E/AndroidRuntime(1023): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.restaurantfinder/com.example.restaurantfinder.MainActivity}: java.lang.NullPointerException
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.os.Handler.dispatchMessage(Handler.java:99)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.os.Looper.loop(Looper.java:137)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.ActivityThread.main(ActivityThread.java:4745)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at java.lang.reflect.Method.invokeNative(Native Method)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at java.lang.reflect.Method.invoke(Method.java:511)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at dalvik.system.NativeStart.main(Native Method)
10-04 16:12:16.631: E/AndroidRuntime(1023): Caused by: java.lang.NullPointerException
10-04 16:12:16.631: E/AndroidRuntime(1023):     at com.example.restaurantfinder.MainActivity.onCreate(MainActivity.java:38)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.Activity.performCreate(Activity.java:5008)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
10-04 16:12:16.631: E/AndroidRuntime(1023):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
10-04 16:12:16.631: E/AndroidRuntime(1023):     ... 11 more

代码：

public class MainActivity extends Activity {
private GoogleMap googleMap;
double latitude = 0;
double longitude = 0;

// create marker
MarkerOptions marker;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    try {
        // Loading map
        initilizeMap();

    } catch (Exception e) {
        e.printStackTrace();
    }
    // create marker
    MarkerOptions marker = new MarkerOptions().position(new LatLng(latitude, longitude)).title("Hello Maps ");

    // adding marker
    googleMap.addMarker(marker);
}

private void initilizeMap() {
    if (googleMap == null) {
        googleMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

        // check if map is created successfully or not
        if (googleMap == null) {
            Toast.makeText(getApplicationContext(),
                    "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                    .show();
        }
    }
}

protected void onResume() 
    {
    super.onResume();
    initilizeMap();
}

感谢您的帮助..

Answer 1

private GoogleMap googleMap=null;

尝试初始化它可能是错误如错误所说

10-04 16:12:16.631: E/AndroidRuntime(1023): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.restaurantfinder/com.example.restaurantfinder.MainActivity}: java.lang.NullPointerException

Answer 2

试试这个 - ＆gt;

private void initilizeMap() {
    Handler handler = new Handler();
    handler.postDelayed(new Runnable() 

       @Override
       public void run() {
           googleMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
           if(googleMap != null) {
              googleMap.addMarker(new MarkerOptions().position(result)).setVisible(true);

              // Move the camera instantly to location with a zoom of 15.
              googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(result, 15));

              // Zoom in, animating the camera.
              googleMap.animateCamera(CameraUpdateFactory.zoomTo(14), 2000, null);

              googleMap.getUiSettings().setZoomControlsEnabled(false);
              googleMap.getUiSettings().setCompassEnabled(false);
              googleMap.getUiSettings().setMyLocationButtonEnabled(false);

              handler.removeCallbacksAndMessages(null);
           }

           else {
                handler.postDelayed(this, 500);
           }
     }, 500);
 }

Answer 3

在主线程上运行地图是个问题。在另一项活动中使用地图这是冰淇淋三明治中的问题，但在果冻豆上它运作良好。

无法在设备上看到Google地图

3 个答案: