【移动应用开发技术】怎么解决android特卖列表倒计时卡顿问题

【移动应用开发技术】怎么解决android特卖列表倒计时卡顿问题

这篇文章将为大家详细讲解有关怎么解决android特卖列表倒计时卡顿问题，在下觉得挺实用的，因此分享给大家做个参考，希望大家阅读完这篇文章后可以有所收获。在Android的开发中，我们经常遇见倒计时的操作，通常使用Timer和Handler共同操作来完成。当然也可以使用Android系统控件CountDownTimer，这里我们封装成一个控件，也方便大家的使用。首先上一张效果图吧：说一下造成卡顿的原因，由于滑动的时候，adapter的getView频繁的创建和销毁，就会出现卡顿和数据错位问题，那么我们每一个item的倒计时就需要单独维护，这里我用的Handler与timer及TimerTask结合的方法，我们知道TimerTask运行在自己子线程，然后通过Timer的schedule（）方法实现倒计时功能，最后通过Hander实现View的刷新，其核心代码如下：public

class

CountDownView

extends

LinearLayout

{

@BindView(R.id.tv_day)

TextView

tvDay;

@BindView(R.id.tv_hour)

TextView

tvHour;

@BindView(R.id.tv_minute)

TextView

tvMinute;

@BindView(R.id.tv_second)

TextView

tvSecond;

@BindView(R.id.day)

TextView

day;

@BindView(R.id.hour)

TextView

hour;

@BindView(R.id.minute)

TextView

minute;

private

Context

context;

private

int

viewBg;//倒计时的背景

private

int

cellBg;//每个倒计时的背景

private

int

cellTextColor;//文字颜色

private

int

textColor;//外部：等颜色

private

int

textSize

=

14;//外部文字大小

private

int

cellTextSize

=

12;//cell文字大小

private

TimerTask

timerTask

=

null;

private

Timer

timer

=

new

Timer();

private

Handler

handler

=

new

Handler()

{

public

void

handleMessage(Message

msg)

{

countDown();

}

};

public

CountDownView(Context

context,

AttributeSet

attrs)

{

this(context,

attrs,

0);

this.context

=

context;

}

public

CountDownView(Context

context,

AttributeSet

attrs,

int

defStyleAttr)

{

super(context,

attrs,

defStyleAttr);

this.context

=

context;

initAttrs(attrs,

defStyleAttr);

initView(context);

}

private

void

initAttrs(AttributeSet

attrs,

int

defStyle)

{

TypedArray

typedArray

=

getContext().obtainStyledAttributes(attrs,

R.styleable.CountDownView,

defStyle,0);

viewBg

=

typedArray.getColor(R.styleable.CountDownView_viewBg,

Color.parseColor("#FFFFFF"));

cellBg

=

typedArray.getColor(R.styleable.CountDownView_cellBg,

Color.parseColor("#F4F4F4"));

cellTextColor

=

typedArray.getColor(R.styleable.CountDownView_cellTextColor,

Color.parseColor("#646464"));

textColor

=

typedArray.getColor(R.styleable.CountDownView_TextColor,

Color.parseColor("#B3B3B3"));

textSize

=

(int)

typedArray.getDimension(R.styleable.CountDownView_TextSize,

UIUtils.dp2px(getContext(),

14));

cellTextSize

=

(int)

typedArray.getDimension(R.styleable.CountDownView_cellTextSize,

UIUtils.dp2px(getContext(),

12));

typedArray.recycle();

}

private

void

initView(Context

context)

{

LayoutInflater

inflater

=

(LayoutInflater)

context

.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

View

view

=

inflater.inflate(R.layout.layout_countdown_layout,

this);

ButterKnife.bind(view);

initProperty();

}

private

void

initProperty()

{

tvDay.setBackgroundColor(cellBg);

tvHour.setBackgroundColor(cellBg);

tvMinute.setBackgroundColor(cellBg);

tvSecond.setBackgroundColor(cellBg);

tvDay.setTextColor(cellTextColor);

tvHour.setTextColor(cellTextColor);

tvMinute.setTextColor(cellTextColor);

tvSecond.setTextColor(cellTextColor);

day.setTextColor(textColor);

hour.setTextColor(textColor);

minute.setTextColor(textColor);

}

public

void

setLeftTime(long

leftTime)

{

if

(leftTime

<=

0)

return;

long

time

=

leftTime

/

1000;

long

day

=

time

/

(3600

*

24);

long

hours

=

(time

-

day

*

3600

*

24)

/

3600;

long

minutes

=

(time

-

day

*

3600

*

24

-

hours

*

3600)

/

60;

long

seconds

=

time

-

day

*

3600

*

24

-

hours

*

3600

-

minutes

*

60;

setTextTime(time);

}

public

void

start()

{

if

(timerTask

==

null)

{

timerTask

=

new

TimerTask()

{

@Override

public

void

run()

{

handler.sendEmptyMessage(0);

}

};

timer.schedule(timerTask,

1000,

1000);

//

timer.schedule(new

TimerTask()

{

//

@Override

//

public

void

run()

{

//

handler.sendEmptyMessage(0);

//

}

//

},

0,

1000);

}

}

public

void

stop()

{

if

(timer

!=

null)

{

timer.cancel();

timer

=

null;

}

}

//保证天，时，分，秒都两位显示，不足的补0

private

void

setTextTime(long

time)

{

String[]

s

=

TimeUtils.formatTimer(time);

tvDay.setText(s[0]);

tvHour.setText(s[1]);

tvMinute.setText(s[2]);

tvSecond.setText(s[3]);

}

private

void

countDown()

{

if

(isCarry4Unit(tvSecond))

{

if

(isCarry4Unit(tvMinute))

{

if

(isCarry4Unit(tvHour))

{

if

(isCarry4Unit(tvDay))

{

stop();

}

}

}

}

}

private

boolean

isCarry4Unit(TextView

tv)

{

int

time

=

Integer.valueOf(tv.getText().toString());

time

=

time

-

1;

if

(time

<

0)

{

time

=

59;

tv.setText(time

+

"");

return

true;

}

else

if

(time

<

10)

{

tv.setText("0"

+

time);

return

false;

}

else

{

tv.setText(time

+

"");

return

false;

}

}

}另一种写法：public

class

CountDownTimerView

extends

LinearLayout

{

private

TextView

hourView,

minuteView,

secondView;

private

LimitTimer

mTimer;

private

Handler

handler;

public

static

final

int

START_LIMIT_TIME_MSG

=

0x0111;

public

static

final

int

END_LIMIT_TIME_MSG

=

0x0112;

private

long

endTime,

leftTime;

private

LimitTimeListener

listener=null;

public

CountDownTimerView(Context

context)

{

super(context);

initView(context);

}

public

CountDownTimerView(Context

context,

AttributeSet

attrs)

{

super(context,

attrs);

initView(context);

}

private

void

initView(Context

context)

{

setOrientation(HORIZONTAL);

setGravity(Gravity.CENTER_VERTICAL);

inflate(context,

R.layout.layout_countdown_layout,

this);

hourView

=

(TextView)

findViewById(R.id.tv_hour);

minuteView

=

(TextView)

findViewById(R.id.tv_minute);

secondView

=

(TextView)

findViewById(R.id.tv_second);

}

public

long

getLeftTime()

{

return

leftTime;

}

//设置剩余时间

public

void

initLeftTime(long

endTime)

{

endTime=endTime*1000;

if

(null

!=

mTimer)

{

mTimer.cancel();

mTimer

=

null;

}

this.endTime

=

endTime;

mTimer

=

new

LimitTimer(endTime,

1000);

mTimer.start();

if

(handler

!=

null)

{

handler.sendEmptyMessage(START_LIMIT_TIME_MSG);

}

}

/**

*

如果该控件使用在碎片中，返回时，则最好还是要stop

*/

public

void

stopTimeCount()

{

if

(null

!=

mTimer)

{

mTimer.cancel();

mTimer

=

null;

}

}

public

Handler

getHandler()

{

return

handler;

}

public

void

setHandler(Handler

handler)

{

this.handler

=

handler;

}

private

class

LimitTimer

extends

CountDownTimer

{

public

LimitTimer(long

millisInFuture,

long

countDownInterval)

{

super(0

!=

leftTime

?

leftTime

:

endTime,

countDownInterval);

}

@Override

public

void

onTick(long

millisUntilFinished)

{

leftTime

=

millisUntilFinished;

long

totalSecond

=

millisUntilFinished

/

1000;

int

second

=

(int)

(totalSecond

%

60);

int

minute

=

(int)

((totalSecond

/

60)

%

60);

int

hour

=

(int)

((totalSecond

/

3600)

%

24);

int

day

=

(int)

(totalSecond

/

(3600

*

24));

formatView(hourView,

hour);

formatView(minuteView,

minute);

formatView(secondView,

second);

}

@Override

public

void

onFinish()

{

String

zero

=

"00";

hourView.setText(zero);

minuteView.setText(zero);

secondView.setText(zero);

if

(null

!=

handler)

{

handler.sendEmptyMessage(END_LIMIT_TIME_MSG);

}

if

(listener!=null){

listener.onTimeOver(true);

}

}

private

void

formatView(TextView

view,

int

time)

{

DecimalFormat

df

=

new

DecimalFormat("#00");

view.setText(df.format(time));

}

}

//倒计时结束监听

public

void

setOnLimitTimeListener(LimitTimeListener

listener)

{

this.listener

=

listener;

}

public

interface

LimitTimeListener

{

void

onTimeOver(boolean

flag);

}

@Override

protected

void

onDetachedFromWindow()

{

super.onDetachedFromWindow();

if

(handler

!=

null)

{

handler.removeMessages(START_LIMIT_TIME_MSG);

}

}

}涉及到的布局文件<?xml

version="1.0"

encoding="utf-8"?>

<LinearLayout

xmlns:android="/apk/res/android"

android:layout_width="wrap_content"

android:layout_height="wrap_content"