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

问题是你试图做的事情不应该被做。你不应该让碎片在其他碎片中膨胀。来自Android的文档:

注意:不能在布局时将布局膨胀为片段 包含<fragment>。只有在添加时才支持嵌套片段 动态地连接到一个片段。

虽然您可以使用这里提供的技巧来完成任务,但我强烈建议您不要这样做。当你试图为包含另一个片段的片段膨胀布局时,不可能确定这些黑客将处理每个新的Android操作系统。

android支持的将一个片段添加到另一个片段的唯一方法是通过来自子片段管理器的事务。

简单地将XML布局更改为空容器(如果需要添加ID):

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

然后在Fragment onViewCreated(View View, @Nullable Bundle savedInstanceState)方法中:

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    FragmentManager fm = getChildFragmentManager();
    SupportMapFragment mapFragment = (SupportMapFragment) fm.findFragmentByTag("mapFragment");
    if (mapFragment == null) {
        mapFragment = new SupportMapFragment();
        FragmentTransaction ft = fm.beginTransaction();
        ft.add(R.id.mapFragmentContainer, mapFragment, "mapFragment");
        ft.commit();
        fm.executePendingTransactions();
    }
    mapFragment.getMapAsync(callback);
}

其他回答

As mentioned by @Justin Breitfeller, @Vidar Wahlberg solution is a hack which might not work in future version of Android. @Vidar Wahlberg perfer a hack because other solution might "cause the map to be recreated and redrawn, which isn't always desirable". Map redraw could be prevented by maintaining the old map fragment, rather than creating a new instance every time. @Matt solution doesn't work for me (IllegalStateException) As quoted by @Justin Breitfeller, "You cannot inflate a layout into a fragment when that layout includes a . Nested fragments are only supported when added to a fragment dynamically."

我的解决方案:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,                              Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_map_list, container, false);

    // init
    //mapFragment = (SupportMapFragment)getChildFragmentManager().findFragmentById(R.id.map);
    // don't recreate fragment everytime ensure last map location/state are maintain
    if (mapFragment == null) {
        mapFragment = SupportMapFragment.newInstance();
        mapFragment.getMapAsync(this);
    }
    FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
    // R.id.map is a layout
    transaction.replace(R.id.map, mapFragment).commit();

    return view;
}

嵌套片段目前不受支持。 试试Support Package,修订版11。

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。

全局声明SupportMapFragment对象

    private SupportMapFragment mapFragment;

在onCreateView()方法中将代码放在下面

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

在onDestroyView()中放入下面的代码

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

    if (mapFragment != null)
        getFragmentManager().beginTransaction().remove(mapFragment).commit();
}

在你的xml文件中放入下面的代码

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

上面的代码解决了我的问题,它的工作很好

我建议替换()而不是attach()/detach()在你的标签处理。

或者,切换到ViewPager。下面是一个示例项目,展示了一个ViewPager,带有选项卡,托管10个地图。