android倒计时

先看一下效果：

具体的实现方式：

package module.countdowntimer;

import android.os.CountDownTimer;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private static final long COUNTER_TIME = 10;
    private Button mRetryButton;
    private boolean mGameOver;
    private boolean mGamePaused;

    private long mTimeRemaining;

    private CountDownTimer mCountDownTimer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mRetryButton = ((Button) findViewById(R.id.retry_button));
        mRetryButton.setVisibility(View.INVISIBLE);
        mRetryButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startGame();
            }
        });
        startGame();
    }

    @Override
    public void onResume() {
        super.onResume();
        if (!mGameOver && mGamePaused) {
            resumeGame();
        }
    }

    private void startGame() {
        mRetryButton.setVisibility(View.INVISIBLE);
        createTimer(COUNTER_TIME);
        mGamePaused = false;
        mGameOver = false;
    }

    private void resumeGame() {
        createTimer(mTimeRemaining);
        mGamePaused = false;
    }

    private void createTimer(long time) {
        final TextView textView = ((TextView) findViewById(R.id.timer));
        if (mCountDownTimer != null) {
            mCountDownTimer.cancel();
        }
        mCountDownTimer = new CountDownTimer(time * 1000, 50) {
            @Override
            public void onTick(long millisUnitFinished) {
                mTimeRemaining = ((millisUnitFinished / 1000) + 1);
                textView.setText("seconds remaining: " + mTimeRemaining);
            }

            @Override
            public void onFinish() {
                textView.setText("You Lose!");
                mRetryButton.setVisibility(View.VISIBLE);
                mGameOver = true;
            }
        };
        mCountDownTimer.start();
    }
}