解析经纬度后，我的Google地图无法工作

debugcn 发表于 Dev

userNoIdea

我想知道我的Google地图有什么问题。当我尝试将一类纬度和经度的值解析为另一类以使用Google地图时，它将无法正常工作。

我从“”获取了URL，我需要将“纬度”和“经度”的值解析为我的Google Map。我可以检索纬度和经度的数据。

但是，当我尝试将值解析为Google Map时，它不起作用，这给了我强制关闭错误。我可以知道我的代码有什么问题吗？

我的onclick部分代码：

public void onClick(View v) {
    // TODO Auto-generated method stub
        Log.d("coords", "lat: " + KEY_LATITUDE + " long: " + KEY_LONGITUDE);
        Intent intent = new Intent(SingleMenuItemActivity.this, map.class);
        intent.putExtra("LAT", KEY_LATITUDE.toString());
        intent.putExtra("LON", KEY_LONGITUDE.toString());
        startActivity(intent);

map.java

public class map extends FragmentActivity {
    // double lat;
    // double lng;

    private GoogleMap map;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.map_shown);

        SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        map = fm.getMap();
        map.animateCamera(CameraUpdateFactory.zoomIn());
        String lat = null;
        String lon = null;
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(LatLng(lat, lon),
                14.0f));

    }

    private LatLng LatLng(String lat, String lon) {
        // TODO Auto-generated method stub

        Bundle extras = getIntent().getExtras();
        lat = extras.getString("LAT");
        lon = extras.getString("LON");
        return null;
    }

}

logcat错误：

08-14 15:21:47.300: E/AndroidRuntime(24718): FATAL EXCEPTION: main
08-14 15:21:47.300: E/AndroidRuntime(24718): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.fambond/com.example.fambond.map}: java.lang.NullPointerException
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.os.Handler.dispatchMessage(Handler.java:99)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.os.Looper.loop(Looper.java:130)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.app.ActivityThread.main(ActivityThread.java:3691)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at java.lang.reflect.Method.invokeNative(Native Method)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at java.lang.reflect.Method.invoke(Method.java:507)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:912)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:670)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at dalvik.system.NativeStart.main(Native Method)
08-14 15:21:47.300: E/AndroidRuntime(24718): Caused by: java.lang.NullPointerException
08-14 15:21:47.300: E/AndroidRuntime(24718):    at maps.al.a.a(Unknown Source)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at maps.ag.af.a(Unknown Source)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at maps.ag.s.a(Unknown Source)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at maps.ag.an.a(Unknown Source)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at bkw.onTransact(SourceFile:83)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.os.Binder.transact(Binder.java:279)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at com.google.android.gms.maps.internal.IGoogleMapDelegate$a$a.moveCamera(Unknown Source)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at com.google.android.gms.maps.GoogleMap.moveCamera(Unknown Source)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at com.example.fambond.map.onCreate(map.java:28)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050)
08-14 15:21:47.300: E/AndroidRuntime(24718):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
08-14 15:21:47.300: E/AndroidRuntime(24718):    ... 11 more

保罗

首先，LatLng方法有2个double作为参数！

其次，您的LatLng方法返回null，因此很明显，您将获得NPE并且您的应用程序将关闭。

尝试相应地更改您的代码：

public void onClick(View v) {
// TODO Auto-generated method stub
    Log.d("coords", "lat: " + KEY_LATITUDE + " long: " + KEY_LONGITUDE);
    Intent intent = new Intent(SingleMenuItemActivity.this, map.class);
    intent.putExtra("LAT", KEY_LATITUDE);
    intent.putExtra("LON", KEY_LONGITUDE);
    startActivity(intent);

然后。

public class map extends FragmentActivity {
 double lat;
 double lng;

private GoogleMap map;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.map_shown);

    lat = getIntent().getDoubleExtra("LAT");
    lon = getIntent().getDoubleExtra("LON");

    SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    map = fm.getMap();
    map.animateCamera(CameraUpdateFactory.zoomIn());
    map.moveCamera(CameraUpdateFactory.newLatLngZoom(getLatLng()),
            14.0f));

}

private LatLng getLatLng() {
    // TODO Auto-generated method stub
    return new LatLng(lat,lon);
}