將引腳放在片段中的地圖片段上

Question

我無法使用推薦的文檔向地圖添加標記，我沒有錯誤，但地圖上沒有出現標記。

我嘗試過以下方法：

    gmap = googleMap;
    gmap.setMinZoomPreference(12);
       LatLng ny = new LatLng(40.7143528, -74.0059731);
        gmap.moveCamera(CameraUpdateFactory.newLatLng(ny));

和

    gmap.addMarker(new MarkerOptions()
                .position(new LatLng(10, 10))
                .title("Hello world"));

這些都不起作用。

這是我的主要活動，

private static MapView mapView;
private GoogleMap gmap;
private static final String MAP_VIEW_BUNDLE_KEY = "MapViewBundleKey";

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

    session = new SessionHandler(getApplicationContext());
    final User user = session.getUserDetails();

    final View background = findViewById(R.id.home_background_view);
    final ViewPager viewPager = (ViewPager) findViewById(R.id.home_view_pager);
    MainPagerAdapter adapter = new MainPagerAdapter(getSupportFragmentManager());
    viewPager.setAdapter(adapter);

    final int colourGreen = ContextCompat.getColor(this, R.color.Green);
    final int colourPink = ContextCompat.getColor(this, R.color.Pink);
    final int colourBlue = ContextCompat.getColor(this, R.color.CafeSeaBlue);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.am_tab_layout);
    tabLayout.setupWithViewPager(viewPager);


    loadLocations();


//        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
//                .findFragmentById(R.id.map);
//        mapFragment.getMapAsync(this);



    viewPager.setCurrentItem(1);
        //mapView = findViewById(R.id.mapView);

    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

                //if on first screen
            if (position == 0)
            {
                background.setBackgroundColor(colourBlue);
                    //background.setAlpha(1-positionOffset);
            }

                //if on mid screen
            else if (position == 1) {
                background.setBackgroundColor(colourPink);
                    //background.setAlpha(positionOffset);
            }

                //if on last screen
            else if (position == 2) {
                background.setBackgroundColor(colourGreen);
                    //background.setAlpha(1+positionOffset);
            }
        }

        @Override
        public void onPageSelected(int position) {
            if(position == 0)
            {

            }if(position == 2){

    //                        gmap.addMarker(new MarkerOptions()
    //                                .position(new LatLng(50, 50))
    //                                .title("Hello world"));

            }

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

}

@Override
public void onConnected(@Nullable Bundle bundle) {

}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

}

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

}

@Override
protected void onStart() {
    super.onStart();


}

@Override
protected void onStop() {
    super.onStop();

}

@Override
public void onLocationChanged(Location location) {
    double currentLatitude = location.getLatitude();
    double currentLongitude = location.getLongitude();

    globalLat = location.getLatitude();
    globalLong = location.getLongitude();

    Log.d("Location","Longitude = "+currentLongitude);
    Log.d("Location","Latitude = "+currentLatitude);



    if(tv1 != null)
        tv1.setText(Double.toString(currentLatitude));


    if(tv2 != null)
        tv2.setText(Double.toString(currentLongitude));

}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}
    //progress bar
private void displayLoader() {
    pDialog = new ProgressDialog(HomeActivity.this);
    pDialog.setMessage("Loading.. Please wait...");
    pDialog.setIndeterminate(false);
    pDialog.setCancelable(false);
    pDialog.show();

}

@Override
public void onItemClick(View view, int position) {
    Toast.makeText(this, "You clicked " + adapter.getItem(position) + " on row number " + position, Toast.LENGTH_SHORT).show();

}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    Bundle mapViewBundle = outState.getBundle(MAP_VIEW_BUNDLE_KEY);
    if (mapViewBundle == null) {
        mapViewBundle = new Bundle();
        outState.putBundle(MAP_VIEW_BUNDLE_KEY, mapViewBundle);
    }

}


@Override
protected void onPause() {
    super.onPause();
}
@Override
protected void onDestroy() {
    super.onDestroy();
}
@Override
public void onLowMemory() {
    super.onLowMemory();
}

@Override
public void onMapReady(GoogleMap map) {
    gmap.addMarker(new MarkerOptions()
        .position(new LatLng(10, 10))
        .title("Hello world"));
}
}

我的布局：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
tools:background="@color/CafeSeaBlue"
android:layout_height="match_parent"
android:layout_width="match_parent"
xmlns:tools="http://schemas.android.com/tools">

<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="80dp"
android:background="@drawable/card_background" />

<android.support.v7.widget.AppCompatTextView
android:id="@+id/latText1"
android:layout_width="match_parent"
android:layout_height="32dp"
android:layout_below="@+id/longText"
android:layout_marginTop="100dp"
android:layout_marginBottom="50dp"
android:background="@color/White"
android:text="Map Screen"
android:textAlignment="center"/>


<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="150dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginBottom="40dp"
tools:context=".HomeActivity"
/>

</FrameLayout>

// SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager() // .findFragmentById(R.id.map); // mapFragment.getMapAsync(this);

在該部分中取消注釋它當前正在意外地崩潰它，說空對象引用

地圖本身加載但我無法獲得它的針腳。 我嘗試了很多方法，可能有相當多的不必要的代碼。

地圖顯示在屏幕上，我會附上一張圖片，但在我能夠之前需要10分。 我無法使用推薦的文檔向地圖添加標記，我沒有錯誤，但地圖上沒有出現標記。

我嘗試過以下方法：

    gmap = googleMap;
    gmap.setMinZoomPreference(12);
       LatLng ny = new LatLng(40.7143528, -74.0059731);
        gmap.moveCamera(CameraUpdateFactory.newLatLng(ny));

和

    gmap.addMarker(new MarkerOptions()
                .position(new LatLng(10, 10))
                .title("Hello world"));

這些都不起作用。

這是我的主要活動，

private static MapView mapView;
private GoogleMap gmap;
private static final String MAP_VIEW_BUNDLE_KEY = "MapViewBundleKey";

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

    session = new SessionHandler(getApplicationContext());
    final User user = session.getUserDetails();

    final View background = findViewById(R.id.home_background_view);
    final ViewPager viewPager = (ViewPager) findViewById(R.id.home_view_pager);
    MainPagerAdapter adapter = new MainPagerAdapter(getSupportFragmentManager());
    viewPager.setAdapter(adapter);

    final int colourGreen = ContextCompat.getColor(this, R.color.Green);
    final int colourPink = ContextCompat.getColor(this, R.color.Pink);
    final int colourBlue = ContextCompat.getColor(this, R.color.CafeSeaBlue);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.am_tab_layout);
    tabLayout.setupWithViewPager(viewPager);


    loadLocations();


//        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
//                .findFragmentById(R.id.map);
//        mapFragment.getMapAsync(this);



    viewPager.setCurrentItem(1);
        //mapView = findViewById(R.id.mapView);

    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

                //if on first screen
            if (position == 0)
            {
                background.setBackgroundColor(colourBlue);
                    //background.setAlpha(1-positionOffset);
            }

                //if on mid screen
            else if (position == 1) {
                background.setBackgroundColor(colourPink);
                    //background.setAlpha(positionOffset);
            }

                //if on last screen
            else if (position == 2) {
                background.setBackgroundColor(colourGreen);
                    //background.setAlpha(1+positionOffset);
            }
        }

        @Override
        public void onPageSelected(int position) {
            if(position == 0)
            {

            }if(position == 2){

    //                        gmap.addMarker(new MarkerOptions()
    //                                .position(new LatLng(50, 50))
    //                                .title("Hello world"));

            }

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

}

@Override
public void onConnected(@Nullable Bundle bundle) {

}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

}

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

}

@Override
protected void onStart() {
    super.onStart();


}

@Override
protected void onStop() {
    super.onStop();

}

@Override
public void onLocationChanged(Location location) {
    double currentLatitude = location.getLatitude();
    double currentLongitude = location.getLongitude();

    globalLat = location.getLatitude();
    globalLong = location.getLongitude();

    Log.d("Location","Longitude = "+currentLongitude);
    Log.d("Location","Latitude = "+currentLatitude);



    if(tv1 != null)
        tv1.setText(Double.toString(currentLatitude));


    if(tv2 != null)
        tv2.setText(Double.toString(currentLongitude));

}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}
    //progress bar
private void displayLoader() {
    pDialog = new ProgressDialog(HomeActivity.this);
    pDialog.setMessage("Loading.. Please wait...");
    pDialog.setIndeterminate(false);
    pDialog.setCancelable(false);
    pDialog.show();

}

@Override
public void onItemClick(View view, int position) {
    Toast.makeText(this, "You clicked " + adapter.getItem(position) + " on row number " + position, Toast.LENGTH_SHORT).show();

}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    Bundle mapViewBundle = outState.getBundle(MAP_VIEW_BUNDLE_KEY);
    if (mapViewBundle == null) {
        mapViewBundle = new Bundle();
        outState.putBundle(MAP_VIEW_BUNDLE_KEY, mapViewBundle);
    }

}


@Override
protected void onPause() {
    super.onPause();
}
@Override
protected void onDestroy() {
    super.onDestroy();
}
@Override
public void onLowMemory() {
    super.onLowMemory();
}

@Override
public void onMapReady(GoogleMap map) {
    gmap.addMarker(new MarkerOptions()
        .position(new LatLng(10, 10))
        .title("Hello world"));
}
}

我的布局：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
tools:background="@color/CafeSeaBlue"
android:layout_height="match_parent"
android:layout_width="match_parent"
xmlns:tools="http://schemas.android.com/tools">

<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="80dp"
android:background="@drawable/card_background" />

<android.support.v7.widget.AppCompatTextView
android:id="@+id/latText1"
android:layout_width="match_parent"
android:layout_height="32dp"
android:layout_below="@+id/longText"
android:layout_marginTop="100dp"
android:layout_marginBottom="50dp"
android:background="@color/White"
android:text="Map Screen"
android:textAlignment="center"/>


<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="150dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginBottom="40dp"
tools:context=".HomeActivity"
/>

</FrameLayout>

// SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager() // .findFragmentById(R.id.map); // mapFragment.getMapAsync(this);

在該部分中取消注釋它當前正在意外地崩潰它，說空對象引用

地圖本身加載但我無法獲得它的針腳。 我嘗試了很多方法，可能有相當多的不必要的代碼。

我會在這里附上顯示和可交互式地圖的圖像，但我沒有10分。 https://i.imgur.com/mpp9aAY.png

Answer 1

您似乎正在將地圖聚焦在紐約市區域，但在尼日利亞中部固定您的標記。 您確定沒有成功添加標記嗎？ 嘗試將標記設置在靠近地圖焦點的位置。

Answer 2

mapFragment = (SupportMapFragment) getChildFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);

這些代碼是必要的，否則你將無法onMapReady(GoogleMap googleMap) {}

我認為發生崩潰是因為變量gmap沒有初始化。 只需在onMapReady中添加標記之前添加gmap = map 。