我有一个带有三个选项卡的应用程序。

每个选项卡都有自己的布局.xml文件。xml有自己的映射片段。它是应用程序第一次启动时显示的那个。

一切都很好,除了当我在制表符之间改变。如果我尝试切换回地图片段选项卡,我会得到这个错误。在其他选项卡之间切换就可以了。

这里会出什么问题呢?

这是我的主类和main.xml,以及我使用的相关类(您还将在底部找到错误日志)

主类

package com.nfc.demo;

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.widget.Toast;

public class NFCDemoActivity extends Activity {

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ActionBar bar = getActionBar();
        bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE);

        bar.addTab(bar
                .newTab()
                .setText("Map")
                .setTabListener(
                        new TabListener<MapFragment>(this, "map",
                                MapFragment.class)));
        bar.addTab(bar
                .newTab()
                .setText("Settings")
                .setTabListener(
                        new TabListener<SettingsFragment>(this, "settings",
                                SettingsFragment.class)));
        bar.addTab(bar
                .newTab()
                .setText("About")
                .setTabListener(
                        new TabListener<AboutFragment>(this, "about",
                                AboutFragment.class)));

        if (savedInstanceState != null) {
            bar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0));
        }
        // setContentView(R.layout.main);

    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("tab", getActionBar().getSelectedNavigationIndex());
    }

    public static class TabListener<T extends Fragment> implements
            ActionBar.TabListener {
        private final Activity mActivity;
        private final String mTag;
        private final Class<T> mClass;
        private final Bundle mArgs;
        private Fragment mFragment;

        public TabListener(Activity activity, String tag, Class<T> clz) {
            this(activity, tag, clz, null);
        }

        public TabListener(Activity activity, String tag, Class<T> clz,
                Bundle args) {
            mActivity = activity;
            mTag = tag;
            mClass = clz;
            mArgs = args;

            // Check to see if we already have a fragment for this tab,
            // probably from a previously saved state. If so, deactivate
            // it, because our initial state is that a tab isn't shown.
            mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
            if (mFragment != null && !mFragment.isDetached()) {
                FragmentTransaction ft = mActivity.getFragmentManager()
                        .beginTransaction();
                ft.detach(mFragment);
                ft.commit();
            }
        }

        public void onTabSelected(Tab tab, FragmentTransaction ft) {
            if (mFragment == null) {
                mFragment = Fragment.instantiate(mActivity, mClass.getName(),
                        mArgs);
                ft.add(android.R.id.content, mFragment, mTag);
            } else {
                ft.attach(mFragment);
            }
        }

        public void onTabUnselected(Tab tab, FragmentTransaction ft) {
            if (mFragment != null) {
                ft.detach(mFragment);
            }
        }

        public void onTabReselected(Tab tab, FragmentTransaction ft) {
            Toast.makeText(mActivity, "Reselected!", Toast.LENGTH_SHORT)
                         .show();
        }
    }

}

main。xml

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

    <fragment
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/mapFragment"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

相关类:MapFragment.java

package com.nfc.demo;

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

public class MapFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        super.onCreateView(inflater, container, savedInstanceState);
        return inflater.inflate(R.layout.main, container, false);
    }

    public void onDestroy() {
        super.onDestroy();
    }
}

错误

android.view.InflateException: Binary XML file line #7: 
     Error inflating class fragment
   at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
   at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
   at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
   at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
   at com.nfc.demo.MapFragment.onCreateView(MapFragment.java:15)
   at android.app.Fragment.performCreateView(Fragment.java:1695)
   at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:885)
   at android.app.FragmentManagerImpl.attachFragment(FragmentManager.java:1255)
   at android.app.BackStackRecord.run(BackStackRecord.java:672)
   at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
   at android.app.FragmentManagerImpl$1.run(FragmentManager.java:441)
   at android.os.Handler.handleCallback(Handler.java:725)
   at android.os.Handler.dispatchMessage(Handler.java:92)
   at android.os.Looper.loop(Looper.java:137)
   at android.app.ActivityThread.main(ActivityThread.java:5039)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:511)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
   at dalvik.system.NativeStart.main(Native Method)

Caused by: java.lang.IllegalArgumentException: 
     Binary XML file line #7: Duplicate id 0x7f040005, tag null, or 
     parent id 0xffffffff with another fragment for 
     com.google.android.gms.maps.MapFragment
   at android.app.Activity.onCreateView(Activity.java:4722)
   at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
   ... 19 more

当前回答

如果你只使用Vidar Wahlberg的答案,当你打开其他活动(例如)并返回到地图时,你会得到错误。或者在我的情况下打开其他活动,然后从新的活动打开地图再次(不使用后退按钮)。 但是当你结合维达尔·沃尔伯格解决方案和马特解决方案时,你将没有例外。

布局

<com.example.ui.layout.MapWrapperLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/map_relative_layout">

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/root">

        <fragment xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/map"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            class="com.google.android.gms.maps.SupportMapFragment" />
    </RelativeLayout>
</<com.example.ui.layout.MapWrapperLayout>

片段

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    setHasOptionsMenu(true);
    if (view != null) {
        ViewGroup parent = (ViewGroup) view.getParent();
        if (parent != null){
            parent.removeView(view);
        }
    }
    try {
        view = inflater.inflate(R.layout.map_view, null);
        if(view!=null){
            ViewGroup root = (ViewGroup) view.findViewById(R.id.root);
...

@Override
public void onDestroyView() {
    super.onDestroyView();
    Fragment fragment = this.getSherlockActivity().getSupportFragmentManager().findFragmentById(R.id.map);
    if (fragment != null)
        getFragmentManager().beginTransaction().remove(fragment).commit();
}

其他回答

如果你只使用Vidar Wahlberg的答案,当你打开其他活动(例如)并返回到地图时,你会得到错误。或者在我的情况下打开其他活动,然后从新的活动打开地图再次(不使用后退按钮)。 但是当你结合维达尔·沃尔伯格解决方案和马特解决方案时,你将没有例外。

布局

<com.example.ui.layout.MapWrapperLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/map_relative_layout">

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/root">

        <fragment xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/map"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            class="com.google.android.gms.maps.SupportMapFragment" />
    </RelativeLayout>
</<com.example.ui.layout.MapWrapperLayout>

片段

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    setHasOptionsMenu(true);
    if (view != null) {
        ViewGroup parent = (ViewGroup) view.getParent();
        if (parent != null){
            parent.removeView(view);
        }
    }
    try {
        view = inflater.inflate(R.layout.map_view, null);
        if(view!=null){
            ViewGroup root = (ViewGroup) view.findViewById(R.id.root);
...

@Override
public void onDestroyView() {
    super.onDestroyView();
    Fragment fragment = this.getSherlockActivity().getSupportFragmentManager().findFragmentById(R.id.map);
    if (fragment != null)
        getFragmentManager().beginTransaction().remove(fragment).commit();
}

我认为有一些错误在以前的App-Compat库的子片段。我试过@维达尔·沃尔伯格和@马特的人,他们对我没用。更新appcompat库后,我的代码运行完美,没有任何额外的努力。

在这个解决方案中,你不需要采取静态变量;

Button nextBtn;

private SupportMapFragment mMapFragment;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    super.onCreateView(inflater, container, savedInstanceState);

    if (mRootView != null) {
        ViewGroup parent = (ViewGroup) mRootView.getParent();
        Utility.log(0,"removeView","mRootView not NULL");
        if (parent != null) {
            Utility.log(0, "removeView", "view removeViewed");
            parent.removeAllViews();
        }
    }
    else {
        try {
            mRootView = inflater.inflate(R.layout.dummy_fragment_layout_one, container, false);//
        } catch (InflateException e) {
    /* map is already there, just return view as it is  */
            e.printStackTrace();
        }
    }

    return  mRootView;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    FragmentManager fm = getChildFragmentManager();
    SupportMapFragment mapFragment = (SupportMapFragment) fm.findFragmentById(R.id.mapView);
    if (mapFragment == null) {
        mapFragment = new SupportMapFragment();
        FragmentTransaction ft = fm.beginTransaction();
        ft.add(R.id.mapView, mapFragment, "mapFragment");
        ft.commit();
        fm.executePendingTransactions();
    }
    //mapFragment.getMapAsync(this);
    nextBtn = (Button) view.findViewById(R.id.nextBtn);
    nextBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Utility.replaceSupportFragment(getActivity(),R.id.dummyFragment,dummyFragment_2.class.getSimpleName(),null,new dummyFragment_2());
        }
    });

}`

Matt建议的答案是可行的,但它会导致地图被重新创建和重新绘制,这并不总是可取的。 经过大量的试验和错误,我找到了一个适合我的解决方案:

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);
    }
    try {
        view = inflater.inflate(R.layout.map, container, false);
    } catch (InflateException e) {
        /* map is already there, just return view as it is */
    }
    return view;
}

下面是"map.xml" (r.b ayout.map)和R.id.mapFragment (android:id="@+id/mapFragment"):

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

    <fragment xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/mapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.SupportMapFragment" />
</LinearLayout>

我希望这能有所帮助,但我不能保证它没有任何不良影响。

Edit: There were some adverse effects, such as when exiting the application and starting it again. Since the application isn't necessarily completely shut down (but just put to sleep in the background), the previous code i submitted would fail upon restarting the application. I've updated the code to something that works for me, both going in & out of the map and exiting and restarting the application, I'm not too happy with the try-catch bit, but it seem to work well enough. When looking at the stack trace it occurred to me that I could just check if the map fragment is in the FragmentManager, no need for the try-catch block, code updated.

更多的编辑:事实证明,你还是需要试接的。只是检查地图碎片,结果并不是很好。Blergh。

我有同样的问题,并能够通过手动删除碎片类的onDestroy()方法中的MapFragment来解决。下面是在XML中通过ID引用MapFragment的代码:

@Override
public void onDestroyView() {
    super.onDestroyView();
    MapFragment f = (MapFragment) getFragmentManager()
                                         .findFragmentById(R.id.map);
    if (f != null) 
        getFragmentManager().beginTransaction().remove(f).commit();
}

如果你不手动删除MapFragment,它会一直挂在那里,这样就不会花费很多资源来重新创建/显示地图视图。看起来,保持底层MapView对于在选项卡之间来回切换是很好的,但是当在片段中使用时,这种行为会导致在每个新的MapFragment上创建一个具有相同ID的重复MapView。解决方案是手动删除MapFragment,从而在每次膨胀片段时重新创建底层映射。

我在另一个答案[1]中也提到了这一点。