Ant-design-mobile: Toast wont show when Modal is open under iOS

[CallMeXYZ]

• [ ] I have searched the issues of this repository and believe that this is not a duplicate.

Version

2.1.10

Environment

iOS 11.3.1

Reproduction link

https://codepen.io/CallMeXYZ/pen/qKBwev?editors=0011

Steps to reproduce

• open link in iOS
• click button and click cancel button of modal

What is expected?

show toast

What is actually happening?

toast won't show under iOS

[xuguogang]

me too.

Picker wont show when Modal is open under iOS

[alex-zhang]

toast level must top than modal

[xuguogang]

这个BUG是Modal与Picker(类似的层组件)共同使用时在Safari中z-index由于translateZ失效引起的，解决方法一个是设置更大的translateZ，

/*
修复Modal与picker共同使用时在Safari中z-index由于translateZ失效问题，
设置am-picker-popup-wrap为translateZ(2px)，以大于Modal的translateZ(1px)
*/
.am-picker-popup-wrap {
-webkit-transform: translateZ(2px);
transform: translateZ(2px)
}

可以参看这篇文章：https://www.cnblogs.com/vickyzhang/articles/7073300.html

[KgTong]

ref #2653