Android中關於多個按鈕放在一起操作的方法

關於多個按鍵放在一起操作的方法：

public class Sudoku extends Activity implements OnClickListener{    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        setContentView(R.layout.main);     super.onCreate(savedInstanceState);                             View continueButton=this.findViewById(R.id.continue_button);        continueButton.setOnClickListener(this);        View newButton =this.findViewById(R.id.new_button);        newButton.setOnClickListener(this);        View aboutButton=this.findViewById(R.id.about_button);        aboutButton.setOnClickListener(this);        View exitButton=this.findViewById(R.id.exit_button);        exitButton.setOnClickListener(this);                  }      public void onClick(View v)    {     switch(v.getId()){     case R.id.about_button:      Intent i=new Intent(this,About.class);      startActivity(i);