<view class="modals modals-bottom-dialog" hidden="{{hideModal}}">
 <view class="modals-cancel" bindtap="hideModal"></view>
 <view class="bottom-dialog-body bottom-pos" animation="{{animationData}}"></view>
</view>

<button bindtap="showModal">点我</button>

/*模态框*/
.modals {
 position: fixed;
 z-index: 999;
 top: 0;
 left: 0;
 right: 0;
 bottom: 0;
}

.modals-cancel {
 position: absolute;
 z-index: 1000;
 top: 0;
 left: 0;
 right: 0;
 bottom: 0;
 background-color: rgba(0, 0, 0, .5);
}

.bottom-dialog-body {
 position: absolute;
 z-index: 10001;
 bottom: 0;
 left: 0;
 right: 0;
 padding: 30rpx;
 height: 800rpx;
 background-color: #fff;
}

/*动画前初始位置*/
.bottom-pos {
 -webkit-transform: translateY(100%);
 transform: translateY(100%);
}

Page({
 data:{
 hideModal:true, //模态框的状态 true-隐藏 false-显示
 animationData:{},//
 },

 // 显示遮罩层
 showModal: function () {
 var that=this;
 that.setData({
 hideModal:false
 })
 var animation = wx.createAnimation({
 duration: 600,//动画的持续时间 默认400ms 数值越大，动画越慢 数值越小，动画越快
 timingFunction: 'ease',//动画的效果 默认值是linear
 })
 this.animation = animation 
 setTimeout(function(){
 that.fadeIn();//调用显示动画
 },200) 
 },

 // 隐藏遮罩层
 hideModal: function () {
 var that=this; 
 var animation = wx.createAnimation({
 duration: 800,//动画的持续时间 默认400ms 数值越大，动画越慢 数值越小，动画越快
 timingFunction: 'ease',//动画的效果 默认值是linear
 })
 this.animation = animation
 that.fadeDown();//调用隐藏动画 
 setTimeout(function(){
 that.setData({
 hideModal:true
 }) 
 },720)//先执行下滑动画，再隐藏模块
 
 },

 //动画集
 fadeIn:function(){
 this.animation.translateY(0).step()
 this.setData({
 animationData: this.animation.export()//动画实例的export方法导出动画数据传递给组件的animation属性
 }) 
 },
 fadeDown:function(){
 this.animation.translateY(300).step()
 this.setData({
 animationData: this.animation.export(), 
 })
 }, 
})