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：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
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：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal"> <TextView android:id="@+id/tv_hour" style="@style/style_countdown" /> <TextView style="@style/style_wrap_content" android:layout_marginLeft="3dp" android:layout_marginRight="3dp" android:layout_gravity="center_vertical" android:text="时" android:textColor="@color/color_646464" /> <TextView android:id="@+id/tv_minute" style="@style/style_countdown" /> <TextView style="@style/style_wrap_content" android:layout_marginLeft="3dp" android:layout_marginRight="3dp" android:layout_gravity="center_vertical" android:text="分" android:textColor="@color/color_646464" /> <TextView android:id="@+id/tv_second" style="@style/style_countdown" /> <TextView style="@style/style_wrap_content" android:layout_marginLeft="3dp" android:layout_marginRight="3dp" android:layout_gravity="center_vertical" android:text="秒" android:textColor="@color/color_646464" /></LinearLayout> |
附上源码地址：点击打开链接
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/xiangzhihong8/article/details/52949385
