compile 'com.jakewharton:butterknife:8.4.0' 
annotationProcessor 'com.jakewharton:butterknife-compiler:8.4.0' 

protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    ButterKnife.bind(this); 
    tv1.setText("hi!sy") 

public class MainActivity extends Activity { 
   @BindView(R.id.tv_time) 
  TextView tvTime; 
  @BindView(R.id.activity_main) 
  RelativeLayout activityMain; 
  @BindView(R.id.tv_cal) 
  TextView tvCal; 
  @BindView(R.id.tv_date) 
  TextView tvDate; 
  Time time; 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    ButterKnife.bind(this); 
    tvTime.setText("Time类"); 
    tvCal.setText("Calender类"); 
    tvDate.setText("Date类"); 
    initTime(); 
  } 
  private void initTime() { 
    time = new Time(); 
    time.setToNow(); 
  } 
  @OnClick({R.id.tv_cal, R.id.tv_date,R.id.tv_time}) 
  public void onClick(View view) { 
    switch (view.getId()) { 
      case R.id.tv_time://点击第一个 
        String times = time.year + "年" + time.month + "月" + time.monthDay 
            + "日" + time.hour + "时" + time.minute + "分" + time.second + "秒" 
            + ":现在是一年中的第" + time.yearDay + "天"; 
        Toast.makeText(this, Time.getCurrentTimezone() + times, Toast.LENGTH_SHORT).show(); 
        tvTime.setText(times); 
        break; 
      case R.id.tv_cal: 
        break; 
      case R.id.tv_date: 
        break; 
    } 
  } 
  @Override 
  protected void onDestroy() { 
    super.onDestroy(); 
//    Unbinder unbinder=ButterKnife.bind(this); 
//    unbinder.unbind(); 
    ButterKnife.bind(this).unbind(); 
  } 
}