Button

1、在布局文件中注册id
activity_main.xml中

   <Button
        android:id="@+id/button"
        android:text="Button"
        android:textAllCaps="false"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

2、在mainActivity中添加监听事件

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //添加监听
        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               //添加逻辑代码
            }
        });
    }
}