TabHost相关

重写TabHost。原因：重启打开过的页面时，代码中设置的ui界面会混乱，重写后使用show和hide来显示或隐藏界面

public class MyFragmentTabHost extends TabHost implements TabHost.OnTabChangeListener{    private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();    private FrameLayout mRealTabContent;    private Context mContext;    private FragmentManager mFragmentManager;    private int mContainerId;    private TabHost.OnTabChangeListener mOnTabChangeListener;    private TabInfo mLastTab;    private boolean mAttached;    static final class TabInfo    {        private final String tag;        private final Class<?> clss;        private final Bundle args;        protected 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;        }    }    static class SavedState extends BaseSavedState    {        String curTab;        SavedState(Parcelable superState)        {            super(superState);        }        private SavedState(Parcel in)        {            super(in);            curTab = in.readString();        }        @Override        public void writeToParcel(Parcel out, int flags)        {            super.writeToParcel(out, flags);            out.writeString(curTab);        }        @Override        public String toString()        {            return "FragmentTabHost.SavedState{"                    + Integer.toHexString(System.identityHashCode(this))                    + " curTab=" + curTab + "}";        }        public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>()        {            public SavedState createFromParcel(Parcel in)            {                return new SavedState(in);            }            public SavedState[] newArray(int size)            {                return new SavedState[size];            }        };    }    public MyFragmentTabHost(Context context)    {        // Note that we call through to the version that takes an AttributeSet,        // because the simple Context construct can result in a broken object!        super(context, null);        initFragmentTabHost(context, null);    }    public MyFragmentTabHost(Context context, AttributeSet attrs)    {        super(context, attrs);        initFragmentTabHost(context, attrs);    }    private void initFragmentTabHost(Context context, AttributeSet attrs)    {        TypedArray a = context.obtainStyledAttributes(attrs,                new int[]{android.R.attr.inflatedId}, 0, 0);        mContainerId = a.getResourceId(0, 0);        a.recycle();        super.setOnTabChangedListener(this);    }    private void ensureHierarchy(Context context)    {        // If owner hasn't made its own view hierarchy, then as a convenience        // we will construct a standard one here.        if (findViewById(android.R.id.tabs) == null)        {            LinearLayout ll = new LinearLayout(context);            ll.setOrientation(LinearLayout.VERTICAL);            addView(ll, new FrameLayout.LayoutParams(                    ViewGroup.LayoutParams.MATCH_PARENT,                    ViewGroup.LayoutParams.MATCH_PARENT));            TabWidget tw = new TabWidget(context);            tw.setId(android.R.id.tabs);            tw.setOrientation(TabWidget.HORIZONTAL);            ll.addView(tw, new LinearLayout.LayoutParams(                    ViewGroup.LayoutParams.MATCH_PARENT,                    ViewGroup.LayoutParams.WRAP_CONTENT, 0));            FrameLayout fl = new FrameLayout(context);            fl.setId(android.R.id.tabcontent);            ll.addView(fl, new LinearLayout.LayoutParams(0, 0, 0));            mRealTabContent = fl = new FrameLayout(context);            mRealTabContent.setId(mContainerId);            ll.addView(fl, new LinearLayout.LayoutParams(                    LinearLayout.LayoutParams.MATCH_PARENT, 0, 1));        }    }    /**     * @deprecated Don't call the original TabHost setup, you must instead call     * {@link #setup(Context, FragmentManager)} or     * {@link #setup(Context, FragmentManager, int)}.     */    @Override    @Deprecated    public void setup()    {        throw new IllegalStateException(                "Must call setup() that takes a Context and FragmentManager");    }    public void setup(Context context, FragmentManager manager)    {        ensureHierarchy(context); // Ensure views required by super.setup()        super.setup();        mContext = context;        mFragmentManager = manager;        ensureContent();    }    public void setup(Context context, FragmentManager manager, int containerId)    {        ensureHierarchy(context); // Ensure views required by super.setup()        super.setup();        mContext = context;        mFragmentManager = manager;        mContainerId = containerId;        ensureContent();        mRealTabContent.setId(containerId);        // We must have an ID to be able to save/restore our state. If        // the owner hasn't set one at this point, we will set it ourself.        if (getId() == View.NO_ID)        {            setId(android.R.id.tabhost);        }    }    private void ensureContent()    {        if (mRealTabContent == null)        {            mRealTabContent = (FrameLayout) findViewById(mContainerId);            if (mRealTabContent == null)            {                throw new IllegalStateException(                        "No tab content FrameLayout found for id "                                + mContainerId);            }        }    }    @Override    public void setOnTabChangedListener(OnTabChangeListener l)    {        mOnTabChangeListener = l;    }    public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args)    {        tabSpec.setContent(new DummyTabFactory(mContext));        String tag = tabSpec.getTag();        TabInfo info = new TabInfo(tag, clss, args);        if (mAttached)        {            // If we are already attached to the window, then check to make            // sure this tab's fragment is inactive if it exists. This shouldn't            // normally happen.            info.fragment = mFragmentManager.findFragmentByTag(tag);            if (info.fragment != null && !info.fragment.isDetached())            {                FragmentTransaction ft = mFragmentManager.beginTransaction();//              ft.detach(info.fragment);                ft.hide(info.fragment);                ft.commit();            }        }        mTabs.add(info);        addTab(tabSpec);    }    @Override    protected void onAttachedToWindow()    {        super.onAttachedToWindow();        String currentTab = getCurrentTabTag();        // Go through all tabs and make sure their fragments match        // the correct state.        FragmentTransaction ft = null;        for (int i = 0; i < mTabs.size(); i++)        {            TabInfo tab = mTabs.get(i);            tab.fragment = mFragmentManager.findFragmentByTag(tab.tag);//          if (tab.fragment != null && !tab.fragment.isDetached()) {            if (tab.fragment != null)            {                if (tab.tag.equals(currentTab))                {                    // The fragment for this tab is already there and                    // active, and it is what we really want to have                    // as the current tab. Nothing to do.                    mLastTab = tab;                } else                {                    // This fragment was restored in the active state,                    // but is not the current tab. Deactivate it.                    if (ft == null)                    {                        ft = mFragmentManager.beginTransaction();                    }//                  ft.detach(tab.fragment);                    ft.hide(tab.fragment);                }            }        }        // We are now ready to go. Make sure we are switched to the        // correct tab.        mAttached = true;        ft = doTabChanged(currentTab, ft);        if (ft != null)        {            ft.commit();            mFragmentManager.executePendingTransactions();        }    }    @Override    protected void onDetachedFromWindow()    {        super.onDetachedFromWindow();        mAttached = false;    }    @Override    protected Parcelable onSaveInstanceState()    {        Parcelable superState = super.onSaveInstanceState();        SavedState ss = new SavedState(superState);        ss.curTab = getCurrentTabTag();        return ss;    }    @Override    protected void onRestoreInstanceState(Parcelable state)    {        SavedState ss = (SavedState) state;        super.onRestoreInstanceState(ss.getSuperState());        setCurrentTabByTag(ss.curTab);    }    @Override    public void onTabChanged(String tabId)    {        if (mAttached)        {            FragmentTransaction ft = doTabChanged(tabId, null);            if (ft != null)            {                ft.commit();            }        }        if (mOnTabChangeListener != null)        {            mOnTabChangeListener.onTabChanged(tabId);        }    }    private FragmentTransaction doTabChanged(String tabId,                                             FragmentTransaction ft)    {        TabInfo newTab = null;        for (int i = 0; i < mTabs.size(); i++)        {            TabInfo tab = mTabs.get(i);            if (tab.tag.equals(tabId))            {                newTab = tab;            }        }        if (newTab == null)        {            throw new IllegalStateException("No tab known for tag " + tabId);        }        if (mLastTab != newTab)        {            if (ft == null)            {                ft = mFragmentManager.beginTransaction();            }            if (mLastTab != null)            {                if (mLastTab.fragment != null)                {//                  ft.detach(mLastTab.fragment);                    ft.hide(mLastTab.fragment);                }            }            if (newTab != null)            {                if (newTab.fragment == null)                {                    newTab.fragment = Fragment.instantiate(mContext,                            newTab.clss.getName(), newTab.args);                    ft.add(mContainerId, newTab.fragment, newTab.tag);                } else                {//                  ft.attach(newTab.fragment);                    ft.show(newTab.fragment);                }            }            mLastTab = newTab;        }        return ft;    }}

XML中（只用修改包名，android:id不需要修改）

<包名.MyFragmentTabHost    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:id="@android:id/tabhost"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:fitsSystemWindows="true">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:orientation="vertical">        <FrameLayout            android:id="@android:id/tabcontent"            android:layout_width="match_parent"            android:layout_height="0dp"            android:layout_weight="1"/>        <!--<View-->        <!--android:layout_width="match_parent"-->        <!--android:layout_height="4dp"-->        <!--android:background="@drawable/bg_shadow"/>-->        <TabWidget            android:id="@android:id/tabs"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_gravity="bottom"            android:background="@color/white"            android:paddingTop="10dp"            android:translationY="3dp"/>    </LinearLayout></包名.MyFragmentTabHost>

主程序中

public class MainActivity extends BaseActivity{    @BindView(android.R.id.tabhost)    MyFragmentTabHost mTabHost;    // 标题    private String mFragmentTags[] = {            "标题一", "标题二", "标题三", "标题四"    };    // 未点击图片    @DrawableRes    private int mImages[] = {            R.mipmap.ic_main56,            R.mipmap.ic_main59,            R.mipmap.ic_main62,            R.mipmap.ic_main65    };    //点击图片    @DrawableRes    private int selectImages[] = {            R.mipmap.ic_zuanz03,            R.mipmap.ic_zuanz05,            R.mipmap.ic_zuanz07,            R.mipmap.ic_zuanz09    };    private Class[] fragments = {Fragment1.class, Fragment2.class, Fragment3.class, Fragment4.class};    @Override    protected void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);        StatusBarCompat.compat(this);        initTab();        selectTab(mFragmentTags[0]);    }    private void initTab()    {        mTabHost.setup(this, getSupportFragmentManager(), android.R.id.tabcontent);        mTabHost.getTabWidget().setDividerDrawable(null); // 去掉分割线        for (int i = 0; i < 4; i++)        {            // Tab按钮添加文字和图片            TabHost.TabSpec tabSpec = mTabHost.newTabSpec(mFragmentTags[i]).setIndicator(getImageView(i));            // 添加Fragment            mTabHost.addTab(tabSpec, fragments[i], null);            // 设置Tab按钮的背景//           mTabHost.getTabWidget().getChildAt(i).findViewById(R.id.iv_tab);            mTabHost.setOnTabChangedListener(new TabHost.OnTabChangeListener()            {                @Override                public void onTabChanged(String tabId)                {                    selectTab(tabId);                }            });        }    }    // 获得图片资源    private View getImageView(int index)    {        @SuppressLint("InflateParams")        View view = getLayoutInflater().inflate(R.layout.layout_tab, null);        ImageView imageView = (ImageView) view.findViewById(R.id.iv_tab);        imageView.setImageResource(mImages[index]);        TextView textView = (TextView) view.findViewById(R.id.tv_tab);        textView.setText(mFragmentTags[index]);        return view;    }    private void selectTab(String tabId)    {        for (int i = 0; i < mFragmentTags.length; i++)        {            View mView = mTabHost.getTabWidget().getChildAt(i);//0是代表第一个Tab            ImageView imageView = (ImageView) mView.findViewById(R.id.iv_tab);//获取控件imageView            TextView textView = (TextView) mView.findViewById(R.id.tv_tab);            if (tabId.equals(mFragmentTags[i]))            {                imageView.setImageResource(selectImages[i]);                textView.setTextColor(getResources().getColor(R.color.bule));            } else            {                imageView.setImageResource(mImages[i]);                textView.setTextColor(getResources().getColor(R.color.home_txt2));            }        }    }    private long firstTime = 0;    @Override    public boolean onKeyDown(int keyCode, KeyEvent event)    {        if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN)        {            if (System.currentTimeMillis() - firstTime > 2000)            {                Toast.makeText(MainActivity.this, "再按一次退出程序", Toast.LENGTH_SHORT).show();                firstTime = System.currentTimeMillis();            } else            {                finish();                System.exit(0);            }            return true;        }        return super.onKeyDown(keyCode, event);    }}