当页面有多个按钮或者监听器时,可以用以下代码方式汇总设置:

public class MainActivity extends AppCompatActivity implements View.OnClickListener {  //此处使用View.OnClickListener接口    private Button btn_down;    private Button btn_up;    private ScrollView scrollView;    private TextView txt_show;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        init();    }    private void init() {        btn_down = (Button) findViewById(R.id.btn_down);        btn_up = (Button) findViewById(R.id.btn_up);        scrollView = (ScrollView) findViewById(R.id.scrollView);        txt_show = (TextView) findViewById(R.id.txt_show); 　　　　//必须为按钮设置(this)监听器        btn_down.setOnClickListener(this);        btn_up.setOnClickListener(this);        StringBuilder sb = new StringBuilder();        for (int i = 1; i <= 100; i++) {            sb.append("呵呵 * " + i + "\n");        }        txt_show.setText(sb.toString());    }    @Override    public void onClick(View v) {        switch (v.getId()) {         //在此处使用Switch来统一管理;            case R.id.btn_down:                scrollView.fullScroll(ScrollView.FOCUS_DOWN);                break;            case R.id.btn_up:                scrollView.fullScroll(ScrollView.FOCUS_UP);                break;        }