我想做的事情似乎很简单,但我在网上找不到任何答案。我有一个对象的NSMutableArray,假设它们是Person对象。我想对NSMutableArray按Person排序。birthDate是一个NSDate。

我认为这与这个方法有关:

NSArray *sortedArray = [drinkDetails sortedArrayUsingSelector:@selector(???)];

在Java中,我将使我的对象实现Comparable,或使用集合。使用内联自定义比较器排序…在Objective-C中怎么做呢?


当前回答

您可以使用以下通用方法来实现您的目的。这应该能解决你的问题。

//Called method
-(NSMutableArray*)sortArrayList:(NSMutableArray*)arrDeviceList filterKeyName:(NSString*)sortKeyName ascending:(BOOL)isAscending{
    NSSortDescriptor *sorter = [[NSSortDescriptor alloc] initWithKey:sortKeyName ascending:isAscending];
    [arrDeviceList sortUsingDescriptors:[NSArray arrayWithObject:sorter]];
    return arrDeviceList;
}

//Calling method
[self sortArrayList:arrSomeList filterKeyName:@"anything like date,name etc" ascending:YES];

其他回答

Swift的协议和函数式编程让这变得非常简单,你只需要让你的类符合Comparable协议,实现协议所需的方法,然后使用sorted(by:)高阶函数来创建一个排序的数组,而不需要使用可变数组。

class Person: Comparable {
    var birthDate: NSDate?
    let name: String

    init(name: String) {
        self.name = name
    }

    static func ==(lhs: Person, rhs: Person) -> Bool {
        return lhs.birthDate === rhs.birthDate || lhs.birthDate?.compare(rhs.birthDate as! Date) == .orderedSame
    }

    static func <(lhs: Person, rhs: Person) -> Bool {
        return lhs.birthDate?.compare(rhs.birthDate as! Date) == .orderedAscending
    }

    static func >(lhs: Person, rhs: Person) -> Bool {
        return lhs.birthDate?.compare(rhs.birthDate as! Date) == .orderedDescending
    }

}

let p1 = Person(name: "Sasha")
p1.birthDate = NSDate() 

let p2 = Person(name: "James")
p2.birthDate = NSDate()//he is older by miliseconds

if p1 == p2 {
    print("they are the same") //they are not
}

let persons = [p1, p2]

//sort the array based on who is older
let sortedPersons = persons.sorted(by: {$0 > $1})

//print sasha which is p1
print(persons.first?.name)
//print James which is the "older"
print(sortedPersons.first?.name)

我只是根据自定义需求做了多级排序。

//对值排序

    [arrItem sortUsingComparator:^NSComparisonResult (id a, id b){

    ItemDetail * itemA = (ItemDetail*)a;
    ItemDetail* itemB =(ItemDetail*)b;

    //item price are same
    if (itemA.m_price.m_selling== itemB.m_price.m_selling) {

        NSComparisonResult result=  [itemA.m_itemName compare:itemB.m_itemName];

        //if item names are same, then monogramminginfo has to come before the non monograme item
        if (result==NSOrderedSame) {

            if (itemA.m_monogrammingInfo) {
                return NSOrderedAscending;
            }else{
                return NSOrderedDescending;
            }
        }
        return result;
    }

    //asscending order
    return itemA.m_price.m_selling > itemB.m_price.m_selling;
}];

https://sites.google.com/site/greateindiaclub/mobil-apps/ios/multilevelsortinginiosobjectivec

Swift版本:5.1

如果您有一个自定义结构或类,并希望对它们进行任意排序,您应该调用sort(),使用一个尾随闭包对指定的字段进行排序。下面是一个使用自定义结构数组的例子,该数组根据特定的属性进行排序:

    struct User {
        var firstName: String
    }

    var users = [
        User(firstName: "Jemima"),
        User(firstName: "Peter"),
        User(firstName: "David"),
        User(firstName: "Kelly"),
        User(firstName: "Isabella")
    ]

    users.sort {
        $0.firstName < $1.firstName
    }

如果你想返回一个排序后的数组,而不是原地排序,可以像这样使用sorted():

    let sortedUsers = users.sorted {
        $0.firstName < $1.firstName
    }
-(NSMutableArray*) sortArray:(NSMutableArray *)toBeSorted 
{
  NSArray *sortedArray;
  sortedArray = [toBeSorted sortedArrayUsingComparator:^NSComparisonResult(id a, id b) 
  {
    return [a compare:b];
 }];
 return [sortedArray mutableCopy];
}

Swift中的数组排序


对于Swifty Person来说,下面是一个非常干净的技术,可以在全球范围内实现上述目标。让我们有一个User类的例子,它有一些属性。

class User: NSObject {
    var id: String?
    var name: String?
    var email: String?
    var createdDate: Date?
}

现在我们有了一个数组,我们需要在createdDate的基础上升序和/或降序排序。因此,让我们添加一个日期比较函数。

class User: NSObject {
    var id: String?
    var name: String?
    var email: String?
    var createdDate: Date?
    func checkForOrder(_ otherUser: User, _ order: ComparisonResult) -> Bool {
        if let myCreatedDate = self.createdDate, let othersCreatedDate = otherUser.createdDate {
            //This line will compare both date with the order that has been passed.
            return myCreatedDate.compare(othersCreatedDate) == order
        }
        return false
    }
}

现在让我们有一个扩展数组为用户。简单地说,让我们为那些只有User对象的数组添加一些方法。

extension Array where Element: User {
    //This method only takes an order type. i.e ComparisonResult.orderedAscending
    func sortUserByDate(_ order: ComparisonResult) -> [User] {
        let sortedArray = self.sorted { (user1, user2) -> Bool in
            return user1.checkForOrder(user2, order)
        }
        return sortedArray
    }
}

升序使用

let sortedArray = someArray.sortUserByDate(.orderedAscending)

降序使用

let sortedArray = someArray.sortUserByDate(.orderedAscending)

同一订单的使用

let sortedArray = someArray.sortUserByDate(.orderedSame)

只有当数组为类型时,上述扩展方法才可访问 [User] || Array<用户> .使用实例