關於android自定義底部選單實現與Fragment間的切換，實現過程大體如下：

attrs.xml中的內容：

<resources>
        <attr name="text" format="string"/>
        <attr name="icon_normal" format="reference"/>
        <attr name="icon_pressed" format="reference"/>
    <declare-styleable name="BottomMenu">
        <attr 
 
name="text"/>
        <attr name="icon_normal"/>
        <attr name="icon_pressed"/>
    </declare-styleable>
</resources>

自定義BottomMenu繼承LinearLayout：

public class BottomMenu extends LinearLayout {
    //xml佈局文字屬性
private TextView mTv;
//xml佈局圖片屬性
private ImageView mIv;
//未選中和選中時圖片資源id
 
private int mIconNormal, mIconPressed;
//區分當前控制元件是否選中
private boolean mIsSelect;
//對應的Fragment
private Fragment mFragment;
//程式內例項化時使用，只傳入context即可。
public BottomMenu(Context context) {
        super(context);
}

    //用與layout檔案例項化，會把xml內的引數同過AttributeSet帶入到view內
public BottomMenu(Context context, @Nullable 
 
AttributeSet attrs) {
        super(context, attrs);
init(attrs);
}

    //第三個主題的style資訊，也會從xml裡帶入
public BottomMenu(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
init(attrs);
}

    @SuppressLint("WrongViewCast")
    private void init(AttributeSet attrs) {
        //載入對用控制元件佈局檔案
LayoutInflater.from(getContext()).inflate(R.layout.layout_custom_bottom_menu, this);
//查詢控制元件
mIv = this.findViewById(R.id.iv_bottom);
mTv = this.findViewById(R.id.tv_bottom);
//通過TypeArray獲取對應自定義屬性值
TypedArray typedArray = getContext().obtainStyledAttributes(attrs,R.styleable.BottomMenu);
String text = typedArray.getString(R.styleable.BottomMenu_text);
mIconNormal = typedArray.getResourceId(R.styleable.BottomMenu_icon_normal,0);
mIconPressed = typedArray.getResourceId(R.styleable.BottomMenu_icon_pressed,0);
mTv.setText(text);
mIv.setImageResource(mIconNormal);
}

    /**
     * 控制元件被選中狀態
     */
public void selected(){
        if(mIsSelect){
            return;
}
        //重新給icon設定被點選時候的圖片
mIv.setImageResource(mIconPressed);
mIsSelect = true;
//重新給文字設定顏色
mTv.setTextColor(getContext().getResources().getColor(R.color.menuSelect));
}

    /**
     * 控制元件未選中狀態
     */
public void unSelect(){
        if(mIsSelect){

        }
        mIsSelect = false;
mIv.setImageResource(mIconNormal);
mTv.setTextColor(getContext().getResources().getColor(R.color.black));
}

    
    public boolean isSelect(){
        return mIsSelect;
}


    /**
     * 設定對應控制元件對應的Fragment
     * @param fragment
*/
public void setFragment(Fragment fragment){
        this.mFragment = fragment;
}

    public Fragment getFragment(){
        return this.mFragment;
}
}

Activity xml佈局使用自定義控制元件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:bottom="http://schemas.android.com/apk/res/cn.puming.struggle.buskiosk"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="cn.puming.struggle.buskiosk.MainActivity">
    <FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="55dp"/>
  <LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_alignParentBottom="true"
android:layout_marginBottom="15dp"
android:orientation="horizontal">
     <cn.puming.struggle.buskiosk.customView.BottomMenu
android:id="@+id/bottom_home"
android:layout_width="match_parent"
android:layout_height="wrap_content"
bottom:icon_normal="@mipmap/ic_menu_home_normal"
bottom:icon_pressed="@mipmap/ic_menu_home_pressed"
android:layout_weight="1"
bottom:text="首頁"/>
     <cn.puming.struggle.buskiosk.customView.BottomMenu
android:id="@+id/bottom_gift"
android:layout_width="match_parent"
android:layout_height="wrap_content"
bottom:icon_normal="@mipmap/ic_menu_welfare_normal"
bottom:icon_pressed="@mipmap/ic_menu_welfare_pressed"
android:layout_weight="1"
bottom:text="禮包"/>
     <cn.puming.struggle.buskiosk.customView.BottomMenu
android:id="@+id/bottom_found"
android:layout_width="match_parent"
android:layout_height="wrap_content"
bottom:icon_normal="@mipmap/ic_menu_community_normal"
bottom:icon_pressed="@mipmap/ic_menu_community_pressed"
android:layout_weight="1"
bottom:text="發現"/>
      <cn.puming.struggle.buskiosk.customView.BottomMenu
android:id="@+id/bottom_msg"
android:layout_width="match_parent"
android:layout_height="wrap_content"
bottom:icon_normal="@mipmap/ic_menu_msg_normal"
bottom:icon_pressed="@mipmap/ic_menu_msg_pressed"
android:layout_weight="1"
bottom:text="訊息"/>
      <cn.puming.struggle.buskiosk.customView.BottomMenu
android:id="@+id/bottom_me"
android:layout_width="match_parent"
android:layout_height="wrap_content"
bottom:icon_normal="@mipmap/ic_menu_personal_normal"
bottom:icon_pressed="@mipmap/ic_menu_personal_pressed"
android:layout_weight="1"
bottom:text="我的"/>
  </LinearLayout>
</RelativeLayout>

Activit中程式碼

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private ImageView mIv;
    private BottomMenu mBottomHome;
    private BottomMenu mBottomGift;
    private BottomMenu mBottomMe;
    private BottomMenu mLastBottomMenu;
    private BottomMenu mBottomFound;
    private BottomMenu mBottomMsg;
    private Fragment mHomeFragment,mGiftFragment,mMeFragment,mMsgFragment,mFoundFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mBottomHome = this.findViewById(R.id.bottom_home);
mBottomGift = this.findViewById(R.id.bottom_gift);
mBottomMe = this.findViewById(R.id.bottom_me);
mBottomFound = this.findViewById(R.id.bottom_found);
mBottomMsg = this.findViewById(R.id.bottom_msg);
mLastBottomMenu = mBottomHome;
mBottomHome.selected();
initFragment();
initEvent();
}

    private void initFragment() {
        mHomeFragment = new HomeFragment();
mGiftFragment = new GiftFragment();
mMeFragment = new MeFragment();
mMsgFragment = new MsgFragment();
mFoundFragment = new FoundFragment();
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.add(R.id.fragment_container,mHomeFragment);
transaction.add(R.id.fragment_container,mGiftFragment);
transaction.add(R.id.fragment_container,mMeFragment);
transaction.add(R.id.fragment_container,mMsgFragment);
transaction.add(R.id.fragment_container,mFoundFragment);
transaction.hide(mGiftFragment);
transaction.hide(mMsgFragment);
transaction.hide(mMeFragment);
transaction.hide(mFoundFragment);
transaction.commit();
mBottomHome.setFragment(mHomeFragment);
mBottomGift.setFragment(mGiftFragment);
mBottomFound.setFragment(mFoundFragment);
mBottomMsg.setFragment(mMsgFragment);
mBottomMe.setFragment(mMeFragment);
}

    private void initEvent() {
        mBottomHome.setOnClickListener(this);
mBottomGift.setOnClickListener(this);
mBottomMe.setOnClickListener(this);
mBottomMsg.setOnClickListener(this);
mBottomFound.setOnClickListener(this);
}


    @Override
public void onClick(View v) {
        BottomMenu bottomMenu = (BottomMenu) v;
        if(bottomMenu.isSelect()){
            return;
}
        bottomMenu.selected();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.show(bottomMenu.getFragment());
        if(mLastBottomMenu != null){
            mLastBottomMenu.unSelect();
transaction.hide(mLastBottomMenu.getFragment());
mLastBottomMenu = bottomMenu;
}

        transaction.commit();
}
}

效果圖：