前言

现在大部分App底部都有一个菜单，实现这个功能也有好多办法：

- TabHost+Fragment
- RadioGroup+Fragment
- FragmentTabHost+Fragment
- 5.0以后有个新控件，BottomNavigator

这篇主要介绍下FragmentTabHost配合Fragment使用

运行效果图

效果图分析

FragmentTabHost简单介绍

首先我们看下官方文档的介绍

OK，接着官方还给出了一份使用的代码，我们也来看下

Activity中使用

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); }}

Fragment中使用

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; }}

FragmentTabHost 布局问题

官方在给出例子的时候，并没有贴出对应的布局文件，这个布局文件有一些要求，所以我就把我自己写的贴出来吧，方便大家观看

<?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>

这里要注意以下几点：

1.我自己自定义了一个FragmentTabHost，因为原来的FragmentTabHost每次切换Fragment事都会走一遍onCreateView（）和onResume（）方法；

2.id必须是android:id=”@android:id/tabhost”这个；

3.里面的FrameLayout的id必须是android:id=”@android:id/tabcontent”

FragmentTabHost 使用

下面就到了具体使用的过程了

1.定义Tab类

因为它属于Tab的一个组合吧，里面包含好多个Tab，所以我们先定义一个Tab类

/** * 主页TAB对应实体 * Created by HFS on 2017/5/7. */public class Tab { private int title; // 文字 private int icon; // 图标 private Class fragment; // 对应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; }}

这里面要对应相应的Fragment，所以需要一个Fragment对象

2.初始化Tab集合

有几个Tab就往Tab集合添加几个Tab

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);

3.setUp

找到该控件之后，就要调用对应的这个方法

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

4.添加TabSpec

到这一步就要添加TabSpec了，有几个Tab，就添加几个TabSpec

for (Tab tab : mTabs){ TabHost.TabSpec tabSpec = mTabhost.newTabSpec(getString(tab.getTitle())); tabSpec.setIndicator(buildIndicator(tab)); mTabhost.addTab(tabSpec,tab.getFragment(),null); } //构建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; }

5.设置默认显示第一个

mTabhost.setCurrentTab(0);

6.设置没有分割线

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

自定义FragmentTabHost类

package com.study.buttomtabdemo.widget;/** * Created by monkey * on 2014/9/24 * 功能描述：修改过的FragmentTabHost,保存fragment实例不销毁 *//* * 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://mit(); } } 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; }}

总结

以上所述是小编给大家介绍的Android 使用FragmentTabHost实现底部菜单功能，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！