android的倒计时类CountDownTimer使用

private CountDownTimer timer = new CountDownTimer(30000, 1000) {

		@Override
		public void onTick(long millisUntilFinished) {
			mCountTv.setText((millisUntilFinished / 1000) + "″后重发");
		}

		@Override
		public void onFinish() {
			cancel();
			mSendTv.setVisibility(View.VISIBLE);
			mCountTv.setVisibility(View.GONE);
		}
	};

@Override
	protected void onPause() {
		super.onPause();
		timer.cancel();
		mSendTv.setVisibility(View.VISIBLE);
		mCountTv.setVisibility(View.GONE);
	}