访问变量输出完成块

Question

我如何在完成区之外访问员工价值，以便在ViewController中的任何位置使用它？>

extension TabsParentViewController{
    class func checkCreateTabPermission(completion: @escaping PermCompletionWithCancel){
        RRS.s.permissionService.checkForPermission(.createTab, completion: { (pass, employee, cancel) in
            if !cancel {
                ActivityLogsBuilder.logActivity(forEmployee: employee, module: .tabs, action: ActivityLogsBuilder.action(from: LogAction.createTab, authorized: pass))
            }
            completion(pass, employee, cancel)
        })
    }
}
    

我如何在完成块之外访问雇员值，以便在ViewController扩展TabsParentViewController {类func checkCreateTabPermission（...]

默认情况下，将checkCreateTabPermission称为：

checkCreateTabPermission { pass, employee, cancel in
    // here you can use the `employee`
}

应该使您能够访问返回的employee。因此，您可以在completion的checkCreateTabPermission中调用所需的方法：

checkCreateTabPermission { pass, employee, cancel in
    myMethod(employee: employee)
}

或者如果要访问completion以外的员工，则可以在返回值后声明一个变量（默认为nil）以保存其值：

var myEmployee: Employee?

checkCreateTabPermission { [weak self] pass, employee, cancel in
    self?.myEmployee = employee
}

// you could use `myEmployee` here, but you have to make sure its not nil,
// in other words, `checkCreateTabPermission` has been called and retrieved one.
if let myUnwrappedEmployee = myEmployee {
    // use `myUnwrappedEmployee`...
}

Answer 1

应该使您能够访问返回的employee。因此，您可以在completion的checkCreateTabPermission中调用所需的方法：