layui previews pdf documents, cancels the pop-up mask layer (notes)

Not much to say, directly on the code:

layui.layer.open({
     title: '文件预览',
     type:2,
     area:['900px','700px'], // 弹出框的宽高
     fixed: false, // 是否固定
     maxmin: true, // 是否允许最大化
     shade: 0, // 隐藏弹框的遮罩层
     content: "" // pdf的地址
})

type: 0 - infobox, default

           1 - page layer

           2 - the iframe layer

           3 - Load layer

           4 - itps layer

 shade: mask layer default: black background with 0.3 transparency, not displayed as 0

The road is long and long, I will search up and down!