Android Studio 导航栏 Android底部导航 使用google material 支持库

1.首先在build.gradle 中添加 implementation 'com.google.android.material:material:1.2.0'

2.在 gradle.properties 文件添加

android.useAndroidX=true

完成上述两步后开始写代码

1.在activi_main.xml布局文件中添加

其中 @drawable/selector 文件代码如下

其中@meau/main代码如下

tips: @drable/home 文件由图所示步骤自动生成 (about dashboard同理)

2.新建java类about.java (和dashboard.java)

3.在about.xml(和dashboard.xml)中

添加相同代码

 4.在mainactivity.java中添加如下代码

 BottomNavigationView bottomNavigationView = findViewById(R.id.navi);
        bottomNavigationView.setSelectedItemId(R.id.Home);
        bottomNavigationView.setonNavigationItemSelectedListener(new BottomNavigationView.onNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                switch (item.getItemId()) {
                    case R.id.about:
                        startActivity(new Intent(getApplicationContext(), about.class));
                        overridePendingTransition(0, 0);
                        return true;
                    case R.id.Dashboard:
                        startActivity(new Intent(getApplicationContext(), dashboard.class));
                        overridePendingTransition(0, 0);
                        return true;
                    case R.id.Home:
                        return true;
                }
                return false;
            }
        });
    }

5.在about.java中添加如下代码  (同理在dashboard.java中添加)

        BottomNavigationView bottomNavigationView = findViewById(R.id.navi);

        bottomNavigationView.setSelectedItemId(R.id.about);

        bottomNavigationView.setonNavigationItemSelectedListener(new BottomNavigationView.onNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                switch (item.getItemId()) {
                    case R.id.Home:
                        startActivity(new Intent(getApplicationContext(), MainActivity.class));
                        overridePendingTransition(0, 0);
                        return true;
                    case R.id.Dashboard:
                        startActivity(new Intent(getApplicationContext(), dashboard.class));
                        overridePendingTransition(0, 0);
                        return true;
                    case R.id.about:
                        return true;
                }
                return false;
            }
        });
    }

别忘了在在AndroidManifest里注册新建的Activity!!!!

效果图: