vue简单实现转盘抽奖

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
/**
动画结束事件兼容
**/
whichTransitionEvent(){
 let el = document.createElement('span'),
 transitions = {
 'transition':'transitionend',
 'OTransition':'oTransitionEnd',
 'MozTransition':'transitionend',
 'WebkitTransition':'webkitTransitionEnd'
 };
 for(let t in transitions){
 if( el.style[t] !== undefined ){
  return transitions[t];
 }
 }
 el = null;
}

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
<template>
 <div>
 <h3>转盘抽奖</h3>
 <div class="round_box" >
  <img class="img_rotate" ref="rotImg" src="../assets/zhuan.png" alt="">
  <div class="center">
  <div class="pointer" ></div>
  </div>
 </div>
 <button @click="toDraw" >点击抽奖</button>
 </div>
</template>

<script>
export default {
 name:'rotaryDraw',
 data() {
 return {
  rotate: 0,
  resetRotate: 0,
  hitId: 1,// 1-10
  drawStatus: false
 }
 },
 async mounted() {
 await this.$nextTick();
 let evenTransition = this.whichTransitionEvent();
 let img = this.$refs.rotImg;
 let that = this;
 const hitAre = [ '30M流量包','20金币','20M流量包','10M流量包','5金币',
    '谢谢参与','10金币','50M流量包','2金币','100M流量包'
   ];
 // 监听 动画结束 
 img.addEventListener(evenTransition,tranHand,false);

 function tranHand() {
  // 复位
  that.resetRotate = that.rotate > 360 ? that.rotate % 360 : 0;
  img.style.transition = "none 0s ease 0s";
  img.style.transform = `rotate(${that.resetRotate}deg)`; 
  alert(`抽奖结果【 ${hitAre[that.hitId - 1]} 】`);
  that.drawStatus = false
 }
 },
 methods: {
 start() {
  this.$refs.rotImg.style.transition = "all 3s ease 0s";
  this.$refs.rotImg.style.transform = `rotate(${this.rotate}deg)`;
 },
 toDraw() {
  if(this.drawStatus){
  console.log('正在抽奖中');
  return
  }
  // 标记状态
  this.drawStatus = true
  /**
  * 圆盘共 10 份 每份 36度, 停位置(id)度数 (id - 1)*36 
  * 基数 3圈 360*4
  * this.rotate 当前角度
  * **/ 
  let reset = 360 * 4;
  let idx = this.getRandomInt(1,11);
  // 设置命中
  this.hitId = idx;
  // 需要多转角度
  let addRotate = this.resetRotate > 0 ? 360 - this.resetRotate : 0;
  // 总共角度
  let allRotate = this.rotate + (idx - 1) * 36 + reset + addRotate;
  // 角度限制
  this.rotate = this.setRotate(allRotate);

  this.start()
 },
 // 递归计算角度 不超过 360*6
 setRotate(deg) {
  let rest = deg - 360;
  return rest > 360*6 ? this.setRotate(rest) : deg;
 },
 getRandomInt(min, max) {
  // 向上收
  min = Math.ceil(min);
  // 向下收
  max = Math.floor(max);
  return Math.floor(Math.random() * (max - min)) + min; //不含最大值，含最小值
 },
 // 动画兼容
 whichTransitionEvent(){
  let el = document.createElement('span'),
  transitions = {
  'transition':'transitionend',
  'OTransition':'oTransitionEnd',
  'MozTransition':'transitionend',
  'WebkitTransition':'webkitTransitionEnd'
  };
  for(let t in transitions){
  if( el.style[t] !== undefined ){
   return transitions[t];
  }
  }
  el = null;
 }
 }

}
</script>

<style lang="scss" >
.img_rotate{
 transform: rotate(0deg);
}
.round_box{
 width: 100%;
 max-width: 375px;
 position: relative;
 overflow: hidden;
 img{
 width: 100%;
 }
 .center{
 position: absolute;
 top: 50%;
 left: 50%;
 transform: translate(-50%,-50%);
 .pointer{
  width: 5px;
  height: 90px;
  background-color: #f40;
  position: absolute;
  top: -90px;
 }
 .pointer::before{
  content:'';
  width: 0;
  height: 0;
  border-top: 15px solid transparent;
  border-right: 15px solid transparent;
  border-bottom: 15px solid #f40;
  border-left: 15px solid transparent;
  position: absolute;
  top: -20px;
  left: 50%;
  transform: translateX(-50%);
 }
 }
}

</style>

1
2
3
4
5
6
7
8
/**
比如：
基数3圈 reset 360*3
停留位置 第二个 （2 - 1）* 36 = 36
总共角度 360*3 + 36
动画停止后，因为还要继续旋转，所以不可能把角度一直增加，因此需要复位 
360*3 + 36 其实可以考虑 就转了 36度，然后再增加需要转的角度
**/