微信小程序实现一个自定义遮罩层效果

<button bindtap="showview">Show</button>
<view class="bg" bindtap='hideview' style='display:{{display}}'></view>
<view class="show" bindtap='hideview' style='display:{{display}}'>申请成功
<view class='txt'>您的密码为:123456</view>
</view>

.bg {
  display: none;
  position: absolute;
  top: 0%;
  left: 0%;
  width: 100%;
  height: 100%;
  background-color: black;
  z-index: 1001;
  -moz-opacity: 0.7;
  opacity: 0.70;
  filter: alpha(opacity=70);
}
.show {
  display: none;
  text-align: center;
  position: absolute;
  top: 45%;
  left: 20%;
  width: 53%;
  height: 10%;
  padding: 8px;
  border: 8px solid #e8e9f7;
  background-color: white;
  z-index: 1002;
  overflow: auto;
}
.txt{
  margin-top: 20rpx;
  font-size: 28rpx;
  color: royalblue
}

Page({
  data: {
    display:''
  },
  showview: function() { 
    this.setData({
      display: "block"
    })
  },
  hideview: function() {
    this.setData({
      display: "none"
    })
  }
})