如何在Android Studio中擴展SupportMapFragment？

我想創建一個具有縮放設置，標記和地圖類型設置的自定義地圖片段，以便我可以在多個活動中重複使用它。我創建的類稱爲「LiteMap」。如何在Android Studio中擴展SupportMapFragment？

我從編譯器中得到一個錯誤 'Incompatible Types' 'Required: com.mypackage.LiteMap' 'Found com.google.android.gms.maps.SupportMapFragment' 其中我叫.newInstance。我假設.newInstance返回父類而不是我的類，但我不知道如何重寫我的類中返回我的「LiteMap」對象。

作爲一種替代方法，我嘗試使用new實例化我的地圖對象，並且我得到以下錯誤，但沒有任何特定的行作爲源，但看起來使用new不會創建LiteMap對象。我想做什麼不可能或愚蠢的做法嗎？

03-29 20:36:52.771 11326-11326/com.tremulant.phield E/AndroidRuntime: FATAL EXCEPTION: main 
    Process: com.tremulant.phield, PID: 11326 
    java.lang.RuntimeException: Unable to resume activity {com.tremulant.phield/com.tremulant.phield.ReviewDetails}: java.lang.NullPointerException: Attempt to invoke interface method 'void maps.ei.bz.o()' on a null object reference 
     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2974) 
     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3005) 
     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2371) 
     at android.app.ActivityThread.access$800(ActivityThread.java:149) 
     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1284) 
     at android.os.Handler.dispatchMessage(Handler.java:102) 
     at android.os.Looper.loop(Looper.java:135) 
     at android.app.ActivityThread.main(ActivityThread.java:5290) 
     at java.lang.reflect.Method.invoke(Native Method) 
     at java.lang.reflect.Method.invoke(Method.java:372) 
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703) 
    Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void maps.ei.bz.o()' on a null object reference 
     at maps.ei.n.b(Unknown Source) 
     at com.google.android.gms.maps.internal.i$a.onTransact(:com.google.android.gms.alldynamite:115) 
     at android.os.Binder.transact(Binder.java:380) 
     at com.google.android.gms.maps.internal.IMapFragmentDelegate$zza$zza.onResume(Unknown Source) 
     at com.google.android.gms.maps.SupportMapFragment$zza.onResume(Unknown Source) 
     at com.google.android.gms.dynamic.zza$7.zzb(Unknown Source) 
     at com.google.android.gms.dynamic.zza.zza(Unknown Source) 
     at com.google.android.gms.dynamic.zza.onResume(Unknown Source) 
     at com.google.android.gms.maps.SupportMapFragment.onResume(Unknown Source) 
     at android.support.v4.app.Fragment.performResume(Fragment.java:2020) 
     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1107) 
     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252) 
     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1234) 
     at android.support.v4.app.FragmentManagerImpl.dispatchResume(FragmentManager.java:2056) 
     at android.support.v4.app.FragmentController.dispatchResume(FragmentController.java:196) 
     at android.support.v4.app.FragmentActivity.onResumeFragments(FragmentActivity.java:505) 
     at android.support.v4.app.FragmentActivity.onPostResume(FragmentActivity.java:494) 
     at android.support.v7.app.AppCompatActivity.onPostResume(AppCompatActivity.java:174) 
     at android.app.Activity.performResume(Activity.java:6119) 
     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2963) 
     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3005)  
     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2371)  
     at android.app.ActivityThread.access$800(ActivityThread.java:149)  
     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1284)  
     at android.os.Handler.dispatchMessage(Handler.java:102)  
     at android.os.Looper.loop(Looper.java:135)  
     at android.app.ActivityThread.main(ActivityThread.java:5290)  
     at java.lang.reflect.Method.invoke(Native Method)  
     at java.lang.reflect.Method.invoke(Method.java:372)  
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)  
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)  
03-29 20:36:52.822 11326-11326/? I/Process: Sending signal. PID: 11326 SIG: 9

LiteMap片段

package com.tremulant.phield; 

import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 

import com.google.android.gms.maps.CameraUpdateFactory; 
import com.google.android.gms.maps.GoogleMap; 
import com.google.android.gms.maps.OnMapReadyCallback; 
import com.google.android.gms.maps.SupportMapFragment; 
import com.google.android.gms.maps.model.LatLng; 
import com.google.android.gms.maps.model.MarkerOptions; 

public class LiteMap extends SupportMapFragment implements OnMapReadyCallback { 
    private GoogleMap mMap; 

    String lat; 
    String lng; 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     //super.onCreate(savedInstanceState); 
     lat = getArguments().getString("Lat"); 
     lng = getArguments().getString("Lng"); 
     return inflater.inflate(R.layout.maplite,null); 

    } 

    @Override 
    public void onMapReady(GoogleMap googleMap) { 
     mMap = googleMap; 

     LatLng mapVenue = new LatLng(Double.parseDouble(lat), Double.parseDouble(lng)); 
     mMap.addMarker(new MarkerOptions().position(mapVenue)); 
     mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(mapVenue, 14.0f)); 
    } 
}

的片段maplite.xml佈局文件

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
      android:orientation="vertical" 
      android:layout_width="25dp" 
      android:layout_height="fill_parent" 
      android:weightSum="10"> 


<fragment 
    android:id="@+id/lmap" 
    android:layout_width="match_parent" 
    android:layout_height="25dp" 
    class="com.tremulant.phield.LiteMap" /> 

</LinearLayout> 



    package com.tremulant.phield; 

import android.content.Intent; 
import android.graphics.Typeface; 
import android.os.Bundle; 
import android.support.v7.widget.Toolbar; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

public class ReviewDetails extends BaseActivity implements View.OnClickListener{ 

private Venue mVenue; 
@Override 
public void onClick(View v) { 
    Intent mapIntent = new Intent(ReviewDetails.this, VenueMap.class); 
    mapIntent.putExtra(VENUE_TRANSFER,mVenue); 
    startActivity(mapIntent); 
} 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_review_details); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 

    getSupportActionBar().setDisplayHomeAsUpEnabled(true); 

    Intent intent = getIntent(); 
    mVenue = (Venue) intent.getSerializableExtra(VENUE_TRANSFER); 

    LiteMap liteMap = new LiteMap(); 
    //lmap.setArguments(args); 
    android.support.v4.app.FragmentTransaction fragmentTransaction = 
      getSupportFragmentManager().beginTransaction(); 
    fragmentTransaction.add(R.id.map_container, liteMap); 
    fragmentTransaction.commit(); 
    } 
}

content_review_details.xml佈局文件

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout 
xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
app:layout_behavior="@string/appbar_scrolling_view_behavior" 
tools:context="com.tremulant.phield.ReviewDetails" 
tools:showIn="@layout/activity_review_details"> 

<FrameLayout 
    android:id="@+id/map_container" 
    android:layout_below="@id/map" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content"> 
    </FrameLayout> 

</RelativeLayout>

我簡化了我的代碼。另外我不明白爲什麼當我粘貼我的代碼在這裏它不正確縮進。啊！現在我的logcat在循環中顯示以下內容。當ReviewDetails活動嘗試加載時，屏幕將保持黑屏。

03-30 20:58:28.364 17076-17076/com.tremulant.phield I/ViewRootImpl: 

ViewRoot's Touch Event : ACTION_DOWN 
03-30 20:58:28.466 17076-17076/com.tremulant.phield I/ViewRootImpl: ViewRoot's Touch Event : ACTION_UP 
03-30 20:58:28.503 17076-17076/com.tremulant.phield I/Timeline: Timeline: Activity_launch_request id:com.tremulant.phield time:25955914 
03-30 20:58:28.552 17076-17076/com.tremulant.phield I/Timeline: Timeline: Activity_launch_request id:com.tremulant.phield time:25955964 
03-30 20:58:28.600 17076-17076/com.tremulant.phield D/ContextHelper: convertTheme. context->name=com.tremulant.phield themeResourceId=2131427455 
03-30 20:58:28.604 17076-17076/com.tremulant.phield D/ContextHelper: convertTheme. context->name=com.tremulant.phield themeResourceId=2131427455 
03-30 20:58:28.606 17076-17076/com.tremulant.phield I/PhoneWindow: [generateLayout] setColorNavigationBar => color=0x ff00796b 
03-30 20:58:28.753 17076-17076/com.tremulant.phield I/zzad: Making Creator dynamically 
03-30 20:58:28.763 17076-17076/com.tremulant.phield W/ResourcesManager: Asset path '/system/framework/com.android.media.remotedisplay.jar' does not exist or contains no resources. 
03-30 20:58:28.763 17076-17076/com.tremulant.phield W/ResourcesManager: Asset path '/system/framework/com.android.location.provider.jar' does not exist or contains no resources. 
03-30 20:58:28.839 17076-17076/com.tremulant.phield D/ChimeraCfgMgr: Reading stored module config 
03-30 20:58:28.878 17076-17076/com.tremulant.phield D/ChimeraFileApk: Primary ABI of requesting process is armeabi-v7a 
03-30 20:58:28.879 17076-17076/com.tremulant.phield I/art: DexFile_isDexOptNeeded failed to open oat file '/data/dalvik-cache/arm/[email protected]@[email protected][email protected]@[email protected]@classes.dex' for file location '/data/data/com.google.android.gms/app_chimera/m/00000000/DynamiteModules-prod.apk': Failed to open oat filename for reading: No such file or directory 
03-30 20:58:28.880 17076-17076/com.tremulant.phield D/ChimeraFileApk: Classloading successful. Optimized code found. 
03-30 20:58:29.044 17076-17076/com.tremulant.phield I/Google Maps Android API: Google Play services client version: 8487000 
03-30 20:58:29.055 17076-17076/com.tremulant.phield I/Google Maps Android API: Google Play services package version: 8703230 
03-30 20:58:29.331 17076-17076/com.tremulant.phield I/Google Maps Android API: Google Play services package version: 8703230 
03-30 20:58:29.339 17076-17076/com.tremulant.phield I/Google Maps Android API: Google Play services package version: 8703230 
03-30 20:58:29.344 17076-17076/com.tremulant.phield I/Google Maps Android API: Google Play services package version: 8703230 
03-30 20:58:29.352 17076-17076/com.tremulant.phield I/Google Maps Android API: Google Play services package version: 8703230 
03-30 20:58:29.361 17076-17076/com.tremulant.phield I/Google Maps Android API: Google Play services package version: 8703230

來源

2016-03-30 Joe Williamson

如果您仍然需要回答：

更改maplite.xml到：

<RelativeLayout 
    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:layout_width="match_parent" 
    android:layout_height="25dp"> 

    <fragment 
     android:id="@+id/map" 
     android:name="com.google.android.gms.maps.SupportMapFragment" 
     class="com.google.android.gms.maps.SupportMapFragment" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" /> 

</RelativeLayout>

在LiteMap片段擴展android.support.v4.app.Fragment而不是SupportMapFragment。

您onCreateView在MapLite片段後放：

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

    SupportMapFragment smf = ((SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map)); 

    smf.getMapAsync(this); 
}

來源

2016-09-06 12:53:36

嗨，哥們感謝這一點。我試圖訪問onCreate（）中的childFragmentManager，並且映射返回null。所以我嘗試了子類化，並在gmaps深處獲得了一個模糊的堆棧跟蹤。 –

不回答最初的問題如何擴展SupportMapFragment。 – Alpha

如何在Android Studio中擴展SupportMapFragment？

回答

相關問題