import com.example.android.supportv4.R;import android.os.Bundle;import android.support.v4.app.FragmentActivity;import android.support.v4.app.FragmentTabHost;/** * This demonstrates how you can implement switching between the tabs of a * TabHost through fragments, using FragmentTabHost. */public class FragmentTabs extends FragmentActivity { private FragmentTabHost mTabHost; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.fragment_tabs);  mTabHost = (FragmentTabHost)findViewById(android.R.id.tabhost);  mTabHost.setup(this, getSupportFragmentManager(), R.id.realtabcontent);  mTabHost.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),    FragmentStackSupport.CountingFragment.class, null);  mTabHost.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),    LoaderCursorSupport.CursorLoaderListFragment.class, null);  mTabHost.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),    LoaderCustomSupport.AppListFragment.class, null);  mTabHost.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),    LoaderThrottleSupport.ThrottledLoaderListFragment.class, null); }}

import com.example.android.supportv4.R;import android.os.Bundle;import android.support.v4.app.Fragment;import android.support.v4.app.FragmentTabHost;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;public class FragmentTabsFragmentSupport extends Fragment { private FragmentTabHost mTabHost; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,   Bundle savedInstanceState) {  mTabHost = new FragmentTabHost(getActivity());  mTabHost.setup(getActivity(), getChildFragmentManager(), R.id.fragment1);  mTabHost.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),    FragmentStackSupport.CountingFragment.class, null);  mTabHost.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),    LoaderCursorSupport.CursorLoaderListFragment.class, null);  mTabHost.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),    LoaderCustomSupport.AppListFragment.class, null);  mTabHost.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),    LoaderThrottleSupport.ThrottledLoaderListFragment.class, null);  return mTabHost; } @Override public void onDestroyView() {  super.onDestroyView();  mTabHost = null; }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context="com.study.buttomtabdemo.MainActivity"> <FrameLayout  android:id="@+id/flayout_content"  android:layout_width="match_parent"  android:layout_height="0dp"  android:layout_weight="1"/> <com.study.buttomtabdemo.widget.FragmentTabHost  android:id="@android:id/tabhost"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:background="#ffffff">  <FrameLayout   android:id="@android:id/tabcontent"   android:layout_width="0dp"   android:layout_height="0dp"   android:layout_weight="0"/> </com.study.buttomtabdemo.widget.FragmentTabHost></LinearLayout>

/** * 主頁TAB對應(yīng)實(shí)體 * Created by HFS on 2017/5/7. */public class Tab { private int title; // 文字 private int icon; // 圖標(biāo) private Class fragment; // 對應(yīng)fragment public Tab(Class fragment,int title, int icon ) {  this.title = title;  this.icon = icon;  this.fragment = fragment; } public int getTitle() {  return title; } public void setTitle(int title) {  this.title = title; } public int getIcon() {  return icon; } public void setIcon(int icon) {  this.icon = icon; } public Class getFragment() {  return fragment; } public void setFragment(Class fragment) {  this.fragment = fragment; }}

 Tab tab_home = new Tab(HomeFragment.class,R.string.home,R.drawable.selector_icon_home);  Tab tab_hot = new Tab(HotFragment.class,R.string.hot,R.drawable.selector_icon_hot);  Tab tab_category = new   Tab(CategoryFragment.class,R.string.catagory,R.drawable.selector_icon_category);  Tab tab_cart = new Tab(CartFragment.class,R.string.cart,R.drawable.selector_icon_cart);  Tab tab_mine = new Tab(MineFragment.class,R.string.mine,R.drawable.selector_icon_mine);  mTabs.add(tab_home);  mTabs.add(tab_hot);  mTabs.add(tab_category);  mTabs.add(tab_cart);  mTabs.add(tab_mine);

 mInflater = LayoutInflater.from(this);  mTabhost = (FragmentTabHost) this.findViewById(android.R.id.tabhost);  mTabhost.setup(this,getSupportFragmentManager(),R.id.flayout_content);

 for (Tab tab : mTabs){   TabHost.TabSpec tabSpec = mTabhost.newTabSpec(getString(tab.getTitle()));   tabSpec.setIndicator(buildIndicator(tab));   mTabhost.addTab(tabSpec,tab.getFragment(),null);  }  //構(gòu)建Indicator  private View buildIndicator(Tab tab){   View view =mInflater.inflate(R.layout.tab_indicator,null);   ImageView img = (ImageView) view.findViewById(R.id.icon_tab);   TextView text = (TextView) view.findViewById(R.id.txt_indicator);   img.setBackgroundResource(tab.getIcon());   text.setText(tab.getTitle());  return view; }

mTabhost.setCurrentTab(0);

mTabhost.getTabWidget().setShowDividers(LinearLayout.SHOW_DIVIDER_NONE);

package com.study.buttomtabdemo.widget;/** * Created by monkey * on 2014/9/24 * 功能描述：修改過的FragmentTabHost,保存fragment實(shí)例不銷毀 *//* * Copyright (C) 2012 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *  http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */  import java.util.ArrayList;  import android.content.Context;  import android.content.res.TypedArray;  import android.os.Bundle;  import android.os.Parcel;  import android.os.Parcelable;  import android.support.v4.app.Fragment;  import android.support.v4.app.FragmentManager;  import android.support.v4.app.FragmentTransaction;  import android.util.AttributeSet;  import android.view.View;  import android.view.ViewGroup;  import android.widget.FrameLayout;  import android.widget.LinearLayout;  import android.widget.TabHost;  import android.widget.TabWidget;/** * Special TabHost that allows the use of {@link Fragment} objects for its tab * content. When placing this in a view hierarchy, after inflating the hierarchy * you must call {@link #setup(Context, FragmentManager, int)} to complete the * initialization of the tab host. * * <p> * Here is a simple example of using a FragmentTabHost in an Activity: * * {@sample * development/samples/Support4Demos/src/com/example/android/supportv4/app/ * FragmentTabs.java complete} * * <p> * This can also be used inside of a fragment through fragment nesting: * * {@sample * development/samples/Support4Demos/src/com/example/android/supportv4/app/ * FragmentTabsFragmentSupport.java complete} */public class FragmentTabHost 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 OnTabChangeListener mOnTabChangeListener; private TabInfo mLastTab; private boolean mAttached; 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 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 Creator<SavedState> CREATOR = new Creator<SavedState>() {   public SavedState createFromParcel(Parcel in) {    return new SavedState(in);   }   public SavedState[] newArray(int size) {    return new SavedState[size];   }  }; } public FragmentTabHost(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 FragmentTabHost(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 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(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.commitAllowingStateLoss();   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; }}