iview modal scrollable属性不生效 后面背景页面还是能滚动

Question

<Modal title="取消任务" v-model="taskCancel" width="380" :scrollable="true" :mask-closable="false"></Modal>

scrollable属性不生效 后面背景页面还是能滚动 版本已经更新到iview@2.0.0-rc.18

npm update iview
business-cli@1.0.0 /www/business_cli
├── UNMET PEER DEPENDENCY bulma@>=0.2
├── iview@2.0.0-rc.18
└── UNMET PEER DEPENDENCY webpack@1.15.0