Ios Swift3错误:无法分配类型为';()';输入';[客户对象]?';
我有一个自定义类,包含如下2个属性Ios Swift3错误:无法分配类型为';()';输入';[客户对象]?';,ios,swift,swift3,Ios,Swift,Swift3,我有一个自定义类,包含如下2个属性 class CustomObjectClass: NSObject { override init() { //AppointmentsDetails } var customName:String? var customDate:Date? } 我正在尝试使用类似字典的date:[CustomObjectClass]按日期创建自定义类的组对象 在尝试遍历对象并添加到字典时,我得到一个错误:无法将类型()的
class CustomObjectClass: NSObject {
override init() {
//AppointmentsDetails
}
var customName:String?
var customDate:Date?
}
我正在尝试使用类似字典的date:[CustomObjectClass]按日期创建自定义类的组对象
在尝试遍历对象并添加到字典时,我得到一个错误:无法将类型()
的值赋给类型[CustomObjectClass]?
代码如下
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewWillAppear(_ animated: Bool) {
var tempCustObj = CustomObjectClass()
var tempCustList = [CustomObjectClass]()
for obj in customlist{
dateDict[obj.customDate!] = tempCustList.append(obj)
//error : Cannot assign value of type '()' to type '[CustomObjectClass]?'
}
}
var custObj = CustomObjectClass()
var customlist = [CustomObjectClass]()
var dateDict = [Date:[CustomObjectClass]]()
}
有人能为这个问题提出解决方案吗
tempCustList.append(obj)
返回Void(“nothing”),因此无法将其添加到字典中
如果要添加obj
,首先需要检查是否存在数组(否则创建一个新数组),将元素附加到数组中,最后设置字典的值
for obj in customlist {
if classesByDate[obj.customDate!] == nil {
classesByDate[obj.customDate!] = [obj]
} else {
classesByDate[obj.customDate!]!.append(obj)
}
}
斯威夫特4 得益于新的字典API,您可以简单地使用初始值设定项:
let classesByDate = Dictionary(grouping: customlist) { $0.customDate! }
如果你想添加一个结果,你需要先添加元素,然后将数组添加到字典中:
tempCustList.append(obj)
dateDict[obj.customDate!]=tempCustList
@nathan-效果很好。谢谢,事情终于解决了。你最终使用的是Swift 3还是Swift 4?