<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:300rpx; 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(),  
    })
  }, 
})