ViewBinding

Android官方在Android Studio 3.6.0之后推出了ViewBinding,具体用法，如下：

1.配置viewBinding

• Android Studio 4.0之前

android {
    viewBinding {
        enabled = true
    }
}

• Android Studio 4.0之后（上面那个也能用）

android {
    buildFeatures {
        viewBinding = true
    }
}

2.代码中使用(kotlin中和这个类似)

public class MainActivity extends AppCompatActivity {
    private ActivityMainBinding binding;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding=ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        binding.btnJump.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(MainActivity.this,FirstActivity.class);
                startActivity(intent);
            }
        });
    }
}