Android实现底部导航菜单的跳转--BottomNavigationView

我不是女神ヾ 2021-11-02 00:02 771阅读 1赞

效果：  
![在这里插入图片描述][20190812194434859.gif]  
项目结构：  
![在这里插入图片描述][20190812200314500.png]  
![在这里插入图片描述][20190812200322198.png]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]  
需要用到design依赖： 现在是：implementation ‘com.android.support:design:28.0.0’  
代码：  
activity\_main.xml

<?xml version="1.0" encoding="utf-8"?>
    <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:app="http://schemas.android.com/apk/res-auto">
        <FrameLayout
            android:id="@+id/frame_fragment"
            android:layout_width="fill_parent"
            android:layout_height="0dp"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toTopOf="@id/bottomNavigationView"/>
        <android.support.design.widget.BottomNavigationView
            android:id="@+id/bottomNavigationView"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:itemBackground="@color/white"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintHeight_percent="0.09"
            app:layout_constraintHorizontal_bias="0.0"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:itemIconTint="@drawable/home_bottom_tab_color_selsctor"
            app:itemTextColor="@drawable/home_bottom_tab_color_selsctor"
            app:menu="@menu/bottom_navigation_main" />
    </android.support.constraint.ConstraintLayout>

my\_fragment.xml(其他两个类似不在累述)

<?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"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
    
        <TextView
            android:id="@+id/textView3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            android:text="我的界面"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            tools:ignore="MissingConstraints" />
    </android.support.constraint.ConstraintLayout>

home\_bottom\_tab\_color\_selsctor.xml

<?xml version="1.0" encoding="utf-8"?>

home\_bottom\_tab\_my\_selector.xml

<?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">
        <item
            android:state_checked="false"
            android:drawable="@drawable/home_bottom_tab_icon_my_normal"
           />
        <item
            android:state_checked="true"
            android:drawable="@drawable/home_bottom_tab_icon_my_highlight"
          />
    </selector>

MainActivity

import android.support.annotation.NonNull;
    import android.support.design.widget.BottomNavigationView;
    import android.support.v4.app.Fragment;
    import android.support.v4.app.FragmentTransaction;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.view.KeyEvent;
    import android.view.MenuItem;
    import android.widget.FrameLayout;
    import android.widget.Toast;
    
    public class MainActivity extends AppCompatActivity {
    
    
        private  BottomNavigationView bottomNavigationView;
        private Fragment work_fragment;
        private Fragment message_fragment;
        private Fragment my_fragment;
        private Fragment[] fragments;
        private int lastfragment;//用于记录上个选择的Fragment
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            initFragment();
        }
    
        private void initFragment() {
            work_fragment = new Work_Fragment();
            message_fragment = new Message_Fragment();
            my_fragment = new My_Fragment();
            fragments = new Fragment[]{message_fragment, work_fragment, my_fragment};
            lastfragment = 0;
            getSupportFragmentManager().beginTransaction().replace(R.id.frame_fragment, message_fragment).show(message_fragment).commit();
            bottomNavigationView = (BottomNavigationView) findViewById(R.id.bottomNavigationView);
    
            bottomNavigationView.setOnNavigationItemSelectedListener(changeFragment);
        }
        private BottomNavigationView.OnNavigationItemSelectedListener changeFragment = new BottomNavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    
                switch (item.getItemId()) {
                    case R.id.action_message: {
                        if (lastfragment != 0) {
                            switchFragment(lastfragment, 0);
                            lastfragment = 0;
                        }
                        return true;
                    }
                    case R.id.action_work: {
                        if (lastfragment != 1) {
                            switchFragment(lastfragment, 1);
                            lastfragment = 1;
    
                        }
    
                        return true;
                    }
                    case R.id.action_my: {
                        if (lastfragment != 2) {
                            switchFragment(lastfragment, 2);
                            lastfragment = 2;
                        }
                        return true;
                    }
                }
                return false;
            }
        };
    
    
        //切换Fragment
        private void switchFragment(int lastfragment, int index) {
            FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
            transaction.hide(fragments[lastfragment]);//隐藏上个Fragment
            if (fragments[index].isAdded() == false) {
                transaction.add(R.id.frame_fragment, fragments[index]);
            }
            transaction.show(fragments[index]).commitAllowingStateLoss();
    
        }
    
    
    
     /*   public boolean onKeyUp(int keyCode, KeyEvent event) {
            //在主界面，连击连两下退出程序
            if(keyCode==KeyEvent.KEYCODE_BACK){
                long secondTime=System.currentTimeMillis();
                if(secondTime-firstTime>800){
                    Toast.makeText(Home_Activity.this,"再按一次返回键退出",Toast.LENGTH_SHORT).show();
                    firstTime=secondTime;
                    return true;
                }else{
                    WelcomeActivity.activity.finish();
                    System.exit(0);
                }
            }
            return super.onKeyUp(keyCode, event);
        }*/
    }

My\_fragment(其他两个类似不在累述)

import android.os.Bundle;
    import android.support.annotation.NonNull;
    import android.support.annotation.Nullable;
    import android.support.v4.app.Fragment;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    
    public class My_Fragment extends Fragment {
        @Override
        public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
            View view=inflater.inflate(R.layout.my_fragment,null);
    
            return view;
        }
    }

全部代码：[https://github.com/EternalMsc/BottomNavigationView][https_github.com_EternalMsc_BottomNavigationView]

[20190812194434859.gif]: /images/20211101/8b796f009d774ef894c23368a0c8b3f6.png
[20190812200314500.png]: /images/20211101/88e7eebd0e224702829d5f181148dbcd.png
[20190812200322198.png]: /images/20211101/1f3ed23ac3444cc0b34a4c84ffffe812.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]: /images/20211101/8a125c3120ea4a2cb81ee0b229312253.png
[https_github.com_EternalMsc_BottomNavigationView]: https://github.com/EternalMsc/BottomNavigationView