Android封装实现短信验证码的获取倒计时

<resources>
    <declare-styleable name="CountDownButton">
        <attr name="millisinfuture" fORMat="integer"/>
        <attr name="countdowninterva" format="integer"/>
        <attr name="normalColor" format="color"/>
        <attr name="countDownColor" format="color"/>
    </declare-styleable>
</resources>

@SuppressLint("AppCompatCustomView")
public class CountDownButton extends Button{
    //总时长
    private long millisinfuture;
    //间隔时长
    private long countdowninterva;
    //默认背景颜色
    private int normalColor;
    //倒计时 背景颜色
    private int countDownColor;
    //是否结束
    private boolean isFinish;
    //定时器
    private CountDownTimer countDownTimer;
    public CountDownButton(Context context) {
        this(context,null);
    }
    public CountDownButton(Context context, AttributeSet attrs) {
        this(context, attrs,0);
    }
    public CountDownButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        TypedArray typedArray = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CountDownButton,defStyleAttr,0);
        //设置默认时长
        millisinfuture = (long) typedArray.getInt(R.styleable.CountDownButton_millisinfuture,60000);
        //设置默认间隔时长
        countdowninterva = (long)typedArray.getInt(R.styleable.CountDownButton_countdowninterva,1000);
        //设置默认背景色
        normalColor = typedArray.getColor(R.styleable.CountDownButton_normalColor,Android.R.color.holo_blue_light);
        //设置默认倒计时 背景色
        countDownColor = typedArray.getColor(R.styleable.CountDownButton_countDownColor,android.R.color.darker_gray);
        typedArray.recycle();
        //默认为已结束状态
        isFinish = true;
        //字体居中
        setGravity(Gravity.CENTER);
        //默认文字和背景色
        normalBackground();
        //设置定时器
        countDownTimer = new CountDownTimer(millisinfuture, countdowninterva) {
            @Override
            public void onTick(long millisUntilFinished) {
                //未结束
                isFinish = false;
                setText((Math.round((double) millisUntilFinished / 1000) - 1) + "秒");
                setBackgroundResource(countDownColor);
            }
            @Override
            public void onFinish() {
                //结束
                isFinish = true;
                normalBackground();
            }
        };
    }
    private void normalBackground(){
        setText("获取验证码");
        setBackgroundResource(normalColor);
    }
    public boolean isFinish() {
        return isFinish;
    }
    public void cancel(){
        countDownTimer.cancel();
    }
    public void start(){
        countDownTimer.start();
    }
}

public class MainActivity extends AppCompatActivity {
    private CountDownButton countDownButton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        countDownButton = ((CountDownButton) findViewById(R.id.countDownButton));
        countDownButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //这里判断是否倒计时结束，避免在倒计时时多次点击导致重复请求接口
                if (countDownButton.isFinish()) {
                    //发送验证码请求成功后调用
                    countDownButton.start();
                }
            }
        });
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (!countDownButton.isFinish()) {
            countDownButton.cancel();
        }
    }
}