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Fragmenttabhost的使用教程讲解

flyfish 2021年02月16日 手机开发 213 0

 

 

1.准备tab的图标,放到mipmap目录下面,大小64x64,准备2种,一种是选中的,一种是未选中的,如下图

 2.重写fragmentabhost,防止调用fragment每次点击tab都要重新调用oncreateview方法.,这里的目录是

 

 代码部分

package com.lingdangmao.demo_zidingyi_textview.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://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 [email protected] Fragment} objects for its tab 
 * content. When placing this in a view hierarchy, after inflating the hierarchy 
 * you must call [email protected] #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: 
 * 
 * [email protected] 
 * 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: 
 * 
 * [email protected] 
 * 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 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; 
        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; 
        } 
    } 
 
    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 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 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 
     *             [email protected] #setup(Context, FragmentManager)} or 
     *             [email protected] #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) { 
                    // ½«detachÌ滻Ϊhide£¬Òþ²ØFragment 
                    // 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 { 
                    // ½«attachÌ滻Ϊshow£¬ÏÔʾFragment 
                    // ft.attach(newTab.fragment); 
                    ft.show(newTab.fragment); 
                } 
            } 
 
            mLastTab = newTab; 
        } 
        return ft; 
    } 
}

 

 3.编写activity_main布局文件

<?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" 
    android:id="@+id/main_root_ll" 
    tools:context="com.lingdangmao.demo_zidingyi_textview.MainActivity"> 
 
    <FrameLayout 
        android:id="@+id/realtabcontent" 
        android:layout_weight="1" 
        android:layout_width="match_parent" 
        android:background="@color/bg_color" 
        android:layout_height="0dp"> 
 
    </FrameLayout> 
    <com.lingdangmao.demo_zidingyi_textview.widget.FragmentTabHost 
        android:id="@+id/tabhost" 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content"> 
        <FrameLayout 
            android:layout_weight="0" 
            android:id="@+id/tabcontent" 
            android:layout_width="0dp" 
            android:layout_height="0dp"> 
        </FrameLayout> 
 
    </com.lingdangmao.demo_zidingyi_textview.widget.FragmentTabHost> 
 
</LinearLayout>

 4.编写mainactivity

public class MainActivity extends AppCompatActivity { 
 
 
    private static final String TAG = "MainActivity"; 
    private FragmentTabHost mTabHost; 
    private LayoutInflater mLayoutInflater; 
    private List<Tab> mTabs=new ArrayList<>(5); 
 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_main); 
 
        initTab(); 
    } 
 
    private void initTab() { 
        mLayoutInflater =LayoutInflater.from(this); 
        mTabHost = findViewById(R.id.tabhost); 
        mTabHost.setup(this,getSupportFragmentManager(),R.id.realtabcontent); 
 
        Tab tab_home =new Tab(R.string.home,R.drawable.selector_icon_home,HomeFragment.class); 
        Tab tab_hot =new Tab(R.string.hot,R.drawable.selector_icon_hot,HotFragment.class); 
        Tab tab_category =new Tab(R.string.catagory,R.drawable.selector_icon_category,CategoryFragment.class); 
        Tab tab_cart =new Tab(R.string.cart,R.drawable.selector_icon_cart,CartFragment.class); 
        Tab tab_mine =new Tab(R.string.mine,R.drawable.selector_icon_mine,MineFragment.class); 
 
        mTabs.add(tab_home); 
        mTabs.add(tab_hot); 
        mTabs.add(tab_category); 
        mTabs.add(tab_cart); 
        mTabs.add(tab_mine); 
 
        for (Tab tab: mTabs) { 
            TabHost.TabSpec tabSpec = mTabHost.newTabSpec(getString(tab.getTitle())); 
 
            tabSpec.setIndicator(buildIndicator(tab)); 
            mTabHost.addTab(tabSpec, tab.getFragment(),null); 
        } 
        //去掉分割线 
        mTabHost.getTabWidget().setShowDividers(LinearLayout.SHOW_DIVIDER_NONE); 
 
        //默认选择第一个 
        mTabHost.setCurrentTab(0); 
    } 
 
    private View buildIndicator(Tab tab){ 
        View view= mLayoutInflater.inflate(R.layout.tab_indicator,null); 
        ImageView imageView =view.findViewById(R.id.icon_tab); 
        TextView textView =view.findViewById(R.id.txt_indicator); 
        imageView.setBackgroundResource(tab.getIcon()); 
        textView.setText(tab.getTitle()); 
        return view; 
    } 
 
}

写tab的样式

 

 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" 
    android:paddingTop="3dp" 
    android:paddingBottom="3dp" 
    android:gravity="center" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 
 
    <android.support.v7.widget.AppCompatImageView 
        android:id="@+id/icon_tab" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" /> 
    <android.support.v7.widget.AppCompatTextView 
        android:layout_marginTop="2dp" 
        android:id="@+id/txt_indicator" 
        android:textColor="@color/selector_tab_text" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" /> 
</LinearLayout>

 

写文字切换的样式

 

 

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android"> 
    <item android:state_selected="true" android:color="#eb4f38" /> 
    <item android:state_active="true" android:color="#eb4f38"/> 
    <item android:state_selected="false" android:color="#a9b7b7" /> 
    <item android:state_active="false" android:color="#a9b7b7"/> 
 
</selector>

写图片切换的样式 ,这里只写了一个,其余参考写就行了 

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android"> 
    <!-- Non focused states --> 
    <item android:state_focused="false" android:state_selected="false" android:state_pressed="false" android:drawable="@mipmap/icon_cart" /> 
    <item android:state_focused="false" android:state_selected="true" android:state_pressed="false" android:drawable="@mipmap/icon_cartfill_press" /> 
    <!-- Focused states --> 
    <item android:state_focused="true" android:state_selected="false" android:state_pressed="false" android:drawable="@mipmap/icon_cartfill_press" /> 
    <item android:state_focused="true" android:state_selected="true" android:state_pressed="false" android:drawable="@mipmap/icon_cartfill_press" /> 
    <!-- Pressed --> 
    <item android:state_selected="true" android:state_pressed="true" android:drawable="@mipmap/icon_cartfill_press" /> 
    <item android:state_pressed="true" android:drawable="@mipmap/icon_cartfill_press" /> 
 
</selector>

 写fragment的布局,随便写了一个

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

 

values下面的

color

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
    <color name="colorPrimary">#3F51B5</color> 
    <color name="colorPrimaryDark">#303F9F</color> 
    <color name="colorAccent">#FF4081</color> 
 
    <color name="bg_color">#f1f1f1</color> 
    <color name="tab_text_unselected">#ccc</color> 
</resources>

string

<resources> 
    <string name="app_name">demo_zidingyi_textview</string> 
    <string name="home">主页</string> 
    <string name="hot">热卖</string> 
    <string name="catagory">分类</string> 
    <string name="cart">购物车</string> 
    <string name="mine">我的</string> 
    <string name="title_activity_ware_detail">WareDetailActivity</string> 
    <string name="share">分享</string> 
</resources>

布局的fragment

public class HotFragment extends Fragment { 
 
 
    @Nullable 
    @Override 
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
        View view =inflater.inflate(R.layout.fragment_hot,container,false); 
        return  view; 
    } 
}

初始化的tab

 

public class Tab { 
    private int title; 
    private int icon; 
    private Class fragment; 
    public Tab(int title,int icon,Class fragment){ 
        this.title=title; 
        this.icon=icon; 
        this.fragment=fragment; 
    } 
 
    public void setFragment(Class fragment) { 
        this.fragment = fragment; 
    } 
 
    public void setIcon(int icon) { 
        this.icon = icon; 
    } 
 
    public void setTitle(int title) { 
        this.title = title; 
    } 
 
    public Class getFragment() { 
        return fragment; 
    } 
 
    public int getIcon() { 
        return icon; 
    } 
 
    public int getTitle() { 
        return title; 
    } 
}

 

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