Android : BottomNavigation底部导航_简单应用

示例图：

1.先创建底部导航需要的图片

res → New → Vector Asset  创建三个矢量图

图片1  baseline_home.xml

图片2  baseline_menu.xml

图片3  baseline_author.xml

图片4  用于操作的图片  baseline_img.xml

2.创建 menu 文件  my_menu.xml

res → New → Android Resource File   类型选择 Menu 

3.创建3个Fragment 页面

res → New → Fragment → Fragment(with ViewModel)

创建了6个文件

HomeFragment.java        HomeViewModel.java        布局文件： fragment_home.xml

MenuFragment.java        MenuViewModel.java        布局文件 ： fragment_menu.xml

AuthorFragment.java        AuthorViewModel.java        布局文件：fragment_author.xml

往布局中添加操作的图片

fragment_home.xml：

fragment_menu.xml        

fragment_author.xml

4.创建Navigation 导航文件 my_Navigation.xml

res → New → Android Resource File   类型选择 Navigation

5.在主布局添加 底部导航（BottomNavigationView） 和 跳转的页面(NavHostFragment)

activity_main.xml

6. 设置主题样式 默认是没有导航栏的

values 目录下 colors.xml 

    #FFBB86FC
    #FF6200EE
    #FF3700B3
    #FF03DAC5
    #FF018786
    #FF000000
    #FFFFFFFF

themes.xml

7. MainActivity.java 

package com.example.mybuttomnavigation;

import android.os.Bundle;

import androidx.appcompat.app.AppCompatActivity;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;

import com.google.android.material.bottomnavigation.BottomNavigationView;

public class MainActivity extends AppCompatActivity {


     // 底部导航
    private BottomNavigationView bottomNavigationView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        bottomNavigationView = findViewById(R.id.bottomNavigationView);
        //导航
        NavController navController = Navigation.findNavController(this, R.id.fragment);
        //设置顶部导航
        AppBarConfiguration configuration = new AppBarConfiguration.Builder(
                //带返回箭头 ←
//                navController.getGraph()
                //不带箭头的 ←
                bottomNavigationView.getMenu()
                // 或者这样写 ←不带箭头
//                R.id.menuFragment,R.id.authorFragment,R.id.homeFragment
        ).build();
        //装配顶部导航
        NavigationUI.setupActionBarWithNavController(this, navController, configuration);
        NavigationUI.setupWithNavController(bottomNavigationView, navController);
    }
}

经过上面这些步骤已经可以跳转了

8.设置动画

旋转：HomeFragment.java

package com.example.mybuttomnavigation;

import android.animation.ObjectAnimator;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;

public class HomeFragment extends Fragment {

    private HomeViewModel mViewModel;
    private ImageView imageView;

    public static HomeFragment newInstance() {
        return new HomeFragment();
    }

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_home, container, false);
        imageView = view.findViewById(R.id.imageView);

        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        mViewModel = new ViewModelProvider(this).get(HomeViewModel.class);
        imageView.setRotation(mViewModel.startAnimation);
        // TODO: Use the ViewModel
        /**设置动画
         *
         * alpha（透明度）
         * scaleX（X轴缩放）
         * scaleY（Y轴缩放）
         * rotation（旋转）
         * translationX（X轴平移）
         * translationY（Y轴平移）
         * */
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(imageView, "rotation", 0.0f);
        //点击事件
        imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 判断动画是在运动 objectAnimator.isRunning() 在运动
                //!objectAnimator.isRunning()取反
                //重新设置旋转角度              当前的角度  旋转到 当前的角度+100，
                objectAnimator.setFloatValues(imageView.getRotation(), imageView.getRotation() + 100);
                mViewModel.startAnimation += 100;
                objectAnimator.start();
            }
        });
    }

}

HomeViewModel.java

package com.example.mybuttomnavigation;

import androidx.lifecycle.ViewModel;

public class HomeViewModel extends ViewModel {
    // TODO: Implement the ViewModel
    float startAnimation = 0;
}

缩放：MenuFragment.java

package com.example.mybuttomnavigation;

import android.animation.ObjectAnimator;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;

public class MenuFragment extends Fragment {

    private MenuViewModel mViewModel;
    private ImageView imageView;

    public static MenuFragment newInstance() {
        return new MenuFragment();
    }

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_menu, container, false);
        imageView = view.findViewById(R.id.imageView);


        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        mViewModel = new ViewModelProvider(this).get(MenuViewModel.class);
        imageView.setScaleX(mViewModel.scaleFactor);
        imageView.setScaleY(mViewModel.scaleFactor);
        // TODO: Use the ViewModel
        /**设置动画
         *
         * alpha（透明度）
         * scaleX（X轴缩放）
         * scaleY（Y轴缩放）
         * rotation（旋转）
         * translationX（X轴平移）
         * translationY（Y轴平移）
         * */
        ObjectAnimator objectAnimatorX = ObjectAnimator.ofFloat(imageView, "scaleX", 0);
        ObjectAnimator objectAnimatorY = ObjectAnimator.ofFloat(imageView, "scaleY", 0);
        objectAnimatorX.setDuration(500);
        objectAnimatorY.setDuration(500);
        //点击事件
        imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 判断动画是在运动 objectAnimator.isRunning() 在运动
                //!objectAnimator.isRunning()取反
                //重新设置缩放            
                objectAnimatorX.setFloatValues(imageView.getScaleX() + 0.1f);
                objectAnimatorY.setFloatValues(imageView.getScaleY() + 0.1f);
                mViewModel.scaleFactor += 0.1;
                objectAnimatorX.start();
                objectAnimatorY.start();
            }
        });

    }

}

MenuViewModel.java 

package com.example.mybuttomnavigation;

import androidx.lifecycle.ViewModel;

public class MenuViewModel extends ViewModel {
    // TODO: Implement the ViewModel
    float scaleFactor = 1 ;
}

平移：AuthorFragment.java

package com.example.mybuttomnavigation;

import android.animation.ObjectAnimator;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;

import java.util.Random;

public class AuthorFragment extends Fragment {

    private AuthorViewModel mViewModel;
    public ImageView imageView;

    public static AuthorFragment newInstance() {
        return new AuthorFragment();
    }

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_author, container, false);
        imageView = view.findViewById(R.id.imageView);
        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        mViewModel = new ViewModelProvider(this).get(AuthorViewModel.class);
        // TODO: Use the ViewModel
        imageView.setX(imageView.getX() + mViewModel.mark);

        // TODO: Use the ViewModel
        /**设置动画
         *
         * alpha（透明度）
         * scaleX（X轴缩放）
         * scaleY（Y轴缩放）
         * rotation（旋转）
         * translationX（X轴平移）
         * translationY（Y轴平移）
         * */
        ObjectAnimator objectAnimatorX = ObjectAnimator.ofFloat(imageView, "x", 0);
        //设置动画500毫秒
        objectAnimatorX.setDuration(500);

        //点击事件
        imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 判断动画是在运动 objectAnimator.isRunning() 在运动
                //!objectAnimator.isRunning()取反
                float dx = new Random().nextBoolean() ? 100 : -100;
                //重新设置缩放            = 当前值 移动到 ， 当前值 + dx
                objectAnimatorX.setFloatValues(imageView.getScaleX(), imageView.getScaleX() + dx);

                mViewModel.mark += dx;
                objectAnimatorX.start();

            }
        });

    }

}

AuthorViewModel.java

package com.example.mybuttomnavigation;

import androidx.lifecycle.ViewModel;

public class AuthorViewModel extends ViewModel {
    // TODO: Implement the ViewModel
    float mark = 0;
}