Android的;切换标签时片段重叠

我试图遵循支持演示示例代码来实现选项卡式片段接口.

顶级,我正在尝试实现两个选项卡,将单个片段与每个选项卡关联,并在相应选择每个选项卡时显示片段.

目前,我有两个问题(但我相信它们是相关的……)

1)每个标签的片段彼此重叠.这可能与不正确的片段附加/分离有关.

2)在某处创建了第三个神秘碎片,并与其他碎片重叠

在模拟器(和物理设备)上,您可以看到在选择任一选项卡时有两个片段重叠

当选择tab1时,片段1和未知片段重叠.

当选择tab2时,片段1和片段2重叠.

屏幕截图的链接(上传照片的声誉不够……)

(tab1重叠)http://s8.postimg.org/kv81yz745/tab1_overlapping.png

(tab2重叠)http://s8.postimg.org/3tf7wvs91/tab2_overlapping.png

在这里,为了演示/清晰的目的,我将每个片段中的文本分开.

这些屏幕截图的链接在我的评论/回复中. (上传超过2个链接的声誉不够……)

活动布局(fragment_tabs.xml)

<TabHost
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent">

<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TabWidget
        android:id="@android:id/tabs"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0"/>

    <FrameLayout
        android:id="@android:id/tabcontent"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_weight="0"/>

    <FrameLayout
        android:id="@+id/realtabcontent"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

</LinearLayout>
</TabHost>

源代码

public class TabbedInfoHome extends SherlockFragmentActivity {

TabHost mTabHost;
TabManager mTabManager;

static String tag1name = "simple1";
static String tag2name = "simple2";

static String tab1string = "You are looking at fragment 1";
static String tab2string = "You are looking at fragment 2";


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.fragment_tabs); 

    if (savedInstanceState == null) {
        // Do first time initialization -- add initial fragment.
        Fragment frag1 = CountingFragment.newInstance(tab1string);
        Fragment frag2 = CountingFragment.newInstance(tab2string);
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

        ft.add(R.id.realtabcontent,frag1,tag1name);
        ft.add(R.id.realtabcontent,frag2,tag2name);

        ft.commit();
    } 
    else {
        mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab"));
    }    

    mTabHost = (TabHost)findViewById(android.R.id.tabhost);
    mTabHost.setup();

    mTabManager = new TabManager(this,mTabHost,R.id.realtabcontent);

    mTabManager.addTab(mTabHost.newTabSpec(tag1name)
                .setIndicator(tag1name),TabbedInfoHome.CountingFragment.class,null);

    mTabManager.addTab(mTabHost.newTabSpec(tag2name)
                .setIndicator(tag2name),null);
}   

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putString("tab",mTabHost.getCurrentTabTag());
}

public static class CountingFragment extends SherlockFragment {
    String displayString;
    String FRAGMENT_TAG = this.getClass().getSimpleName();



    /**
     * Create a new instance of CountingFragment,providing "num"
     * as an argument.
     */
    static CountingFragment newInstance(String todisplay) {
        CountingFragment f = new CountingFragment();

        Bundle args = new Bundle();
        args.putString("string",todisplay);
        f.setArguments(args);
        return f;
    }

     /* When creating,retrieve this instance's number from its arguments. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);         
        displayString = getArguments() != null ? getArguments().getString("string") : "no string was passed in!";
    }


    /* The Fragment's UI is just a simple text view showing its
     * instance number. */
    @Override
    public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {

        View v = inflater.inflate(R.layout.hello_world,container,false);
        View tv = v.findViewById(R.id.text);

        boolean separateStrings = false;

        /* the overlapping is hard to decipher,so
         *  lets illustrate how both fragments are appearing */
        if(separateStrings) {

            String temp;

            /* b/c I only created TWO instances of the CountingFragments object,*  there should only be TWO "displayStrings" to consider...
             */
            if( (displayString.compareto(tab1string) == 0) ) {
                /* user clicked tab 1 */
                temp = "\n\n\n\n" + displayString;
            }
            else if( (displayString.compareto(tab2string) == 0) ) {
                /* user clicked tab2 */
                temp = "\n\n\n\n\n\n\n" + displayString;
            }
            else {
                /* unkNown CountingFragment instance */
                temp = "What am I doing here..??? ";
            }

            ((TextView)tv).setText(temp);

        }
        else {
            /* normal case of the fragment being shown; (but they overlap!) */
            ((TextView)tv).setText(displayString);
        }


        return v;
    }
}

/**
 * This is a helper class that implements a generic mechanism for
 * associating fragments with the tabs in a tab host.  It relies on a
 * trick.  normally a tab host has a simple API for supplying a View or
 * Intent that each tab will show.  This is not sufficient for switching
 * between fragments.  So instead we make the content part of the tab host
 * 0dp high (it is not shown) and the TabManager supplies its own dummy
 * view to show as the tab content.  It listens to changes in tabs,and takes
 * care of switch to the correct fragment shown in a separate content area
 * whenever the selected tab changes.
 */
public static class TabManager implements TabHost.OnTabchangelistener {
    private final FragmentActivity mActivity;
    private final TabHost mTabHost;
    private final int mContainerId;
    private final HashMap<String,TabInfo> mTabs = new HashMap<String,TabInfo>();
    TabInfo mLastTab;

    static final class TabInfo {
        private final String tag;
        private final Class<?> clss;
        private final Bundle args;
        private Fragment fragment;

        TabInfo(String _tag,Class<?> _class,Bundle _args) {
            tag = _tag;
            clss = _class;
            args = _args;
        }
    }

    static class DummyTabFactory implements TabHost.TabContentFactory {
        private final Context mContext;

        public DummyTabFactory(Context context) {
            mContext = context;
        }

        @Override
        public View createTabContent(String tag) {
            View v = new View(mContext);
            v.setMinimumWidth(0);
            v.setMinimumHeight(0);
            return v;
        }
    }

    public TabManager(FragmentActivity activity,TabHost tabHost,int containerId) {
        mActivity = activity;
        mTabHost = tabHost;
        mContainerId = containerId;
        mTabHost.setonTabChangedListener(this);
    }

    public void addTab(TabHost.TabSpec tabSpec,Class<?> clss,Bundle args) {

        tabSpec.setContent(new DummyTabFactory(mActivity));
        String tag = tabSpec.getTag();

        TabInfo info = new TabInfo(tag,clss,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.
        info.fragment = mActivity.getSupportFragmentManager().findFragmentByTag(tag);


        if (info.fragment != null ) {  // && !info.fragment.isDetached()) {
            Log.d("addingTab","we already have a fragment for this tab. tabInfo.fragment.id: " + info.fragment.getId());
            FragmentTransaction ft = mActivity.getSupportFragmentManager().beginTransaction();
            ft.detach(info.fragment);
            ft.commit();
            mActivity.getSupportFragmentManager().executePendingTransactions();
        }

        // associate the tabSpec tag with a particular TabInfo object
        mTabs.put(tag,info);
        mTabHost.addTab(tabSpec);
    }

    @Override
    public void onTabChanged(String tabId) {
        TabInfo newTab = mTabs.get(tabId);

        if (mLastTab != newTab) {
            FragmentTransaction ft = mActivity.getSupportFragmentManager().beginTransaction();
            if (mLastTab != null) {
                if (mLastTab.fragment != null) {
                    ft.detach(mLastTab.fragment);
                }
            }

            if (newTab != null) {
                if (newTab.fragment == null) {
                    newTab.fragment = Fragment.instantiate(mActivity,newTab.clss.getName(),newTab.args);

                    ft.add(mContainerId,newTab.fragment,newTab.tag);
                } else {
                    ft.attach(newTab.fragment);
                }
            }

            mLastTab = newTab;
            ft.commit();
            mActivity.getSupportFragmentManager().executePendingTransactions();
        }
    }

}