Custom BottomBar + TabLayout + ViewPager

開發工具：Android Studio3.3.1， compileSdkVersion=28.0.0 ，gradle=gradle-4.10.1-all.zip
時間：2019/3/1
編程語言：Kotlin
功能：底部點擊切換，子頁滑動或者點擊切換
測試手機：華爲榮耀8，Android version 8.0.0（Oreo）， API=26
簡述：點擊底部的切換頁面，第二頁的頭部點擊和滑動均可切換頁面。
個人吐槽：其中的名字出自2019年1月6日開播的日劇《3年A班-從此刻起，大家都是我的人質》
GitHub: https://github.com/SAKURA96/RotationTest
效果圖：

---

GO：
1 build.gradle(Module:app)/dependencies添加依賴
implementation ‘com.android.support:design:28.0.0’

2 app/res中新建color文件夾，在color文件夾中新建bottom_text_selector.xml,底部導航欄字的顏色選擇器

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!--選中時的顏色-->
    <item android:color="#000000" android:state_enabled="false"/>
    <!--未選中時的顏色-->
    <item android:color="#A9A9A9" android:state_enabled="true"/>
</selector>

3 任意選擇十張底部圖片，我選擇的圖片爲 material-design-icons-1.0.0\social\drawable-hdpi中的圖片
4 底部導航欄圖片選擇器,在res/drawable中新建五個xml
bottom_pic_selectot_a.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!--選中時-->
    <item android:drawable="@drawable/ic_group_black_48dp" android:state_enabled="false" />
    <!--未選中時-->
    <item android:drawable="@drawable/ic_group_grey600_48dp" android:state_enabled="true" />
</selector>

bottom_pic_selectot_b.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!--選中時-->
    <item android:drawable="@drawable/ic_mood_black_48dp" android:state_enabled="false" />
    <!--未選中時-->
    <item android:drawable="@drawable/ic_mood_grey600_48dp" android:state_enabled="true" />
</selector>

bottom_pic_selectot_c.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!--選中時-->
    <item android:drawable="@drawable/ic_notifications_black_48dp" android:state_enabled="false" />
    <!--未選中時-->
    <item android:drawable="@drawable/ic_notifications_grey600_48dp" android:state_enabled="true" />
</selector>

bottom_pic_selectot_d.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!--選中時-->
    <item android:drawable="@drawable/ic_public_black_48dp" android:state_enabled="false" />
    <!--未選中時-->
    <item android:drawable="@drawable/ic_public_grey600_48dp" android:state_enabled="true" />
</selector>

bottom_pic_selectot_e.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!--選中時-->
    <item android:drawable="@drawable/ic_school_black_48dp" android:state_enabled="false" />
    <!--未選中時-->
    <item android:drawable="@drawable/ic_school_grey600_48dp" android:state_enabled="true" />
</selector>

5 activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:id="@+id/main">

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

    <View android:layout_width="match_parent"
          android:layout_height="1dp"
          android:background="#808080"/>

    <LinearLayout
            android:id="@+id/bottom_bar"
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_weight="0">

        <LinearLayout android:layout_width="0dp"
                      android:layout_weight="1"
                      android:layout_height="match_parent"
                      android:orientation="vertical"
                      android:padding="3dp">
            <ImageView android:layout_width="match_parent"
                       android:layout_height="0dp"
                       android:layout_weight="5"
                       android:src="@drawable/bottom_pic_selector_a"/>
            <TextView
                    android:layout_width="match_parent"
                    android:layout_height="0dp"
                    android:layout_weight="2"
                    android:layout_gravity="bottom"
                    android:gravity="center_horizontal"
                    android:textSize="12sp"
                    android:textColor="@color/bottom_text_selector"
                    android:text="柊一颯"/>
        </LinearLayout>

        <LinearLayout android:layout_width="0dp"
                      android:layout_weight="1"
                      android:layout_height="match_parent"
                      android:orientation="vertical"
                      android:padding="3dp">
            <ImageView android:layout_width="match_parent"
                       android:layout_height="0dp"
                       android:layout_weight="5"
                       android:src="@drawable/bottom_pic_selector_b"/>
            <TextView
                    android:layout_width="match_parent"
                    android:layout_height="0dp"
                    android:layout_weight="2"
                    android:layout_gravity="bottom"
                    android:gravity="center_horizontal"
                    android:textSize="12sp"
                    android:textColor="@color/bottom_text_selector"
                    android:text="甲斐隼人"/>
        </LinearLayout>

        <LinearLayout android:layout_width="0dp"
                      android:layout_weight="1"
                      android:layout_height="match_parent"
                      android:orientation="vertical"
                      android:padding="3dp">
            <ImageView android:layout_width="match_parent"
                       android:layout_height="0dp"
                       android:layout_weight="5"
                       android:src="@drawable/bottom_pic_selector_c"/>
            <TextView
                    android:layout_width="match_parent"
                    android:layout_height="0dp"
                    android:layout_weight="2"
                    android:layout_gravity="bottom"
                    android:gravity="center_horizontal"
                    android:textSize="12sp"
                    android:textColor="@color/bottom_text_selector"
                    android:text="宇佐美香帆"/>
        </LinearLayout>

        <LinearLayout android:layout_width="0dp"
                      android:layout_weight="1"
                      android:layout_height="match_parent"
                      android:orientation="vertical"
                      android:padding="3dp">
            <ImageView android:layout_width="match_parent"
                       android:layout_height="0dp"
                       android:layout_weight="5"
                       android:src="@drawable/bottom_pic_selector_d"/>
            <TextView
                    android:layout_width="match_parent"
                    android:layout_height="0dp"
                    android:layout_weight="2"
                    android:layout_gravity="bottom"
                    android:gravity="center_horizontal"
                    android:textSize="12sp"
                    android:textColor="@color/bottom_text_selector"
                    android:text="森崎瑞希"/>
        </LinearLayout>

        <LinearLayout android:layout_width="0dp"
                      android:layout_weight="1"
                      android:layout_height="match_parent"
                      android:orientation="vertical"
                      android:padding="3dp">
            <ImageView android:layout_width="match_parent"
                       android:layout_height="0dp"
                       android:layout_weight="5"
                       android:src="@drawable/bottom_pic_selector_e"/>
            <TextView
                    android:layout_width="match_parent"
                    android:layout_height="0dp"
                    android:layout_weight="2"
                    android:layout_gravity="bottom"
                    android:gravity="center_horizontal"
                    android:textSize="12sp"
                    android:textColor="@color/bottom_text_selector"
                    android:text="熊澤花戀"/>
        </LinearLayout>

    </LinearLayout>

</LinearLayout>

6 兩個Fragment的xml文件
fragment_a.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <TextView android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              app:layout_constraintBottom_toBottomOf="parent"
              app:layout_constraintLeft_toLeftOf="parent"
              app:layout_constraintRight_toRightOf="parent"
              app:layout_constraintTop_toTopOf="parent"
              android:textSize="24sp"
              android:text="填充頁"/>

</android.support.constraint.ConstraintLayout>

fragment_b.xml

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

    <android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="40dp"
            app:tabIndicatorColor="#000000"
            app:tabIndicatorHeight="2dp"
            app:tabSelectedTextColor="#000000"
            app:tabTextColor="#A9A9A9">
    </android.support.design.widget.TabLayout>

    <android.support.v4.view.ViewPager
            android:id="@+id/view_pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
    </android.support.v4.view.ViewPager>

</LinearLayout>

7 兩個Fragment的類

AFragment

import android.os.Bundle
import android.support.v4.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup

class AFragment:Fragment() {

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {

        return View.inflate(activity,R.layout.fragment_a,null)
    }
}

BFragment

import android.os.Bundle
import android.support.v4.app.Fragment
import android.support.v4.app.FragmentManager
import android.support.v4.app.FragmentPagerAdapter
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import kotlinx.android.synthetic.main.fragment_b.*

class BFragment : Fragment() {

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {

        return View.inflate(activity, R.layout.fragment_b, null)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        view_pager.adapter = ViewPagerAdapter(childFragmentManager)
        tab_layout.setupWithViewPager(view_pager)
    }


    inner class ViewPagerAdapter(fragmentManager: FragmentManager) : FragmentPagerAdapter(fragmentManager) {

        private val fragments = listOf<Fragment>(AFragment(), AFragment())
        private val titles = listOf("景山澪奈", "水越涼音")

        override fun getItem(position: Int): Fragment {
            return fragments[position]
        }

        override fun getCount(): Int {
            return titles.size
        }

        override fun getPageTitle(position: Int): CharSequence? {
            return titles[position]
        }

    }
}

8 MainActivity

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.v4.app.Fragment
import android.view.View
import android.view.ViewGroup
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        bottomBar()
        //默認加載第一個fragment
        changeIndex(0)
    }

    private val fragments = listOf<Fragment>(AFragment(), BFragment(), AFragment(), AFragment(), AFragment())

    private fun bottomBar() {
        for (i in 0 until bottom_bar.childCount) {
            bottom_bar.getChildAt(i).setOnClickListener { changeIndex(i) }
        }
    }

    private fun changeIndex(index: Int) {
        for (i in 0 until bottom_bar.childCount) {
            val view = bottom_bar.getChildAt(i)
            if (i == index) {
                //選中 禁用,此tab不可再被點擊
                setEnable(view, false)
            } else {
                //沒選中 enable = true，監聽點擊
                setEnable(view, true)
            }
        }
        supportFragmentManager.beginTransaction().replace(R.id.main_content, fragments[index]).commit()
    }

    private fun setEnable(view: View, isEnable: Boolean) {
        view.isEnabled = isEnable
        if (view is ViewGroup) {
            for (i in 0 until view.childCount) {
                view.getChildAt(i).isEnabled = isEnable
            }

        }
    }
}