内置模态框：参数backdrop设置为字符串 'static' ，点击背景依旧会关闭

[guoguo13]

version： ^1.0.10

code： doHotelsSearch() { this.dialogService.show(<BuiltInOptions>{ content: '<div><img class="" src="assets/images/logo/LOGO_1_large.png">加载中...</div>', className:'img-loading', showCancelButton: false, showConfirmButton: false, backdrop: 'static' }) }