Schedule a countdown until a time in the future, with regular notifications on intervals along the way. Example of showing a 30 second countdown in a text field:
new CountDownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
}
public void onFinish() {
mTextField.setText(“done!”);
}
}.start();

 new CountDownTimer(30000, 1000) {
   public void onTick(long millisUntilFinished) {
     mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
   }
   public void onFinish() {
     mTextField.setText("done!");
   }
 }.start();

 /**
 * @param millisInFuture The number of millis in the future from the call to start()
 *           until the countdown is done and onFinish() is called.
 * @param countDownInterval The interval along the way to receive onTick(long) callbacks.
 */
 public CountDownTimer(long millisInFuture, long countDownInterval) {
   mMillisInFuture = millisInFuture;
   mCountdownInterval = countDownInterval;
 }

new CountDownTimer(millisUntilFinished, 1000) {
  /**
   * 當(dāng)前任務(wù)每完成一次倒計(jì)時(shí)間隔時(shí)間時(shí)回調(diào)
   * @param millisUntilFinished
   */
  public void onTick(long millisUntilFinished) {
    if (btn_Code != null) {
      //按鈕不可用
      btn_Code.setClickable(false);
      btn_Code.setEnabled(false);
      btn_Code.setText(millisUntilFinished / 1000 + "s");
    }
  }

  /**
   * 倒計(jì)時(shí)完成后回調(diào)
   */
  public void onFinish() {
    if (btn_Code != null) {
      //按鈕可用
      btn_Code.setText("重新獲取");
      btn_Code.setClickable(true);
      btn_Code.setEnabled(true);
    }
    //取消倒計(jì)時(shí)
    cancel();
  }
}.start();