android - 在 ViewPager fragment 中使用 Google map V2 时崩溃？

Question

我尝试在 Android 应用中使用 Google map v2 时遇到问题。

我的计划是拥有一个包含两个页面的viewpager(一个“详细信息”页面和一个“googlemap”页面)

我已经设置了整个事情，它给了我一些奇怪的结果:

当我开始滑动到“googlemap”页面时，在动画中间(就像我将 viewpager 按住一半一样)，我可以看到 map 正确加载。它就在那里。

我设置的所有内容(标记、相机、动画...)都按预期运行。

但是一旦我完成了滑动，并且谷歌地图页面占据了整个屏幕，整个事情就崩溃了。

知道是什么原因造成的吗？

这是所有相关代码:

FragmentMap.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <fragment
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="200dp"/>

</RelativeLayout>

MapFragment.java

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;

public class MapFragment extends Fragment {

    private GoogleMap map;
    private static View view;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        if (view != null) 
        {
            ViewGroup parent = (ViewGroup) view.getParent();
            if (parent != null)
                parent.removeView(view);
        }
        view = inflater.inflate(R.layout.fragment_map, container, false);
        map = ((SupportMapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

        getActivity().getSupportFragmentManager().popBackStack();
        return view;

    }

    public static MapFragment newInstance() {
        MapFragment f = new MapFragment();
        return f;
    }
}

DetailActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;

public class DetailActivity extends FragmentActivity {

    int extraID;

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

        Intent prevIntent = getIntent();
        extraID = prevIntent.getIntExtra("selected_ID", 0);

        ViewPager pager = (ViewPager) findViewById(R.id.viewpager);
        pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
    }

    private class MyPagerAdapter extends FragmentPagerAdapter {

        public MyPagerAdapter(FragmentManager fm) {
            super(fm);
        }
        @Override
        public Fragment getItem(int pos) {
            switch (pos) {
            case 0:
                return DetailFragment.newInstance(extraID);
            case 1:
                return MapFragment.newInstance();
            default:
                return null;
            }
        }

        @Override
        public int getCount() {
            return 2;
        }
    }
}

detailHolder.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

编辑: logcat

09-28 13:41:42.830: E/AndroidRuntime(12693): FATAL EXCEPTION: main
09-28 13:41:42.830: E/AndroidRuntime(12693): java.lang.NullPointerException
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.support.v4.app.BackStackRecord.doAddOp(BackStackRecord.java:394)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.support.v4.app.BackStackRecord.add(BackStackRecord.java:389)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.support.v4.app.FragmentPagerAdapter.instantiateItem(FragmentPagerAdapter.java:99)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:832)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.support.v4.view.ViewPager.populate(ViewPager.java:1048)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.support.v4.view.ViewPager$3.run(ViewPager.java:244)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.view.Choreographer.doCallbacks(Choreographer.java:562)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.view.Choreographer.doFrame(Choreographer.java:531)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.os.Handler.handleCallback(Handler.java:725)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.os.Handler.dispatchMessage(Handler.java:92)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.os.Looper.loop(Looper.java:137)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at android.app.ActivityThread.main(ActivityThread.java:5230)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at java.lang.reflect.Method.invokeNative(Native Method)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at java.lang.reflect.Method.invoke(Method.java:525)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:799)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
09-28 13:41:42.830: E/AndroidRuntime(12693):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

以下是我的观点:

1. 将detailHolder.xml更改为detailholder.xml android xml文件全部小写

2. 此代码可能会导致 map 问题

   if (parent != null)
   parent.removeView(view);
   

您正在使用相对布局，并且删除与该布局关联的任何 View ，这将影响字段中的所有布局。您可以使用其他布局，例如线性布局。

您的代码不完整。您如何使用 DetailFragment。