排序嵌套的NSMutableArray

Question

的NSMutableArray我想這樣的排列來看：

(
     { 
      "title" = "Bags"; 
      "price" = "$200"; 
     }, 
     { 
      "title" = "Watches"; 
      "price" = "$40"; 
     }, 
     { 
      "title" = "Earrings"; 
      "price" = "$1000"; 
     } 
) 

這其中包含的NSMutableArray個集合的NSMutableArray。我想先按price排序，然後按title排序。

NSSortDescriptor *sortByPrices = [[NSSortDescriptor alloc] initWithKey:@"price" ascending:YES]; 
NSSortDescriptor *sortByTitle = [[NSSortDescriptor alloc] initWithKey:@"title" ascending:YES]; 

[arrayProduct sortedArrayUsingDescriptors:[NSArray arrayWithObjects:sortByPrices,sortByTitle,nil]]; 

但是，似乎沒有工作，如何排序嵌套NSMutableArray？

Answer 1

我想錯誤是price是一個字符串。因此，它不是數字比較，而是按字母順序。嘗試使用比較塊排序的陣列和分析該塊，而不是裏面的價格：

[array sortUsingComparator:^(id _a, id _b) { 
    NSDictionary *a = _a, *b = _b; 

    // primary key is the price 
    int priceA = [[a[@"price"] substringFromIndex:1] intValue]; 
    int priceB = [[b[@"price"] substringFromIndex:1] intValue]; 

    if (priceA < priceB) 
     return NSOrderedAscending; 
    else if (priceA > priceB) 
     return NSOrderedDescending; 
    else // if the prices are the same, sort by name 
     return [a[@"title"] compare:b[@"title"]]; 
}]; 

Answer 2

試試這個

Apple doc

這也有助於你

Answer 3

嘗試

NSMutableArray *arrayProducts = [@[@{@"price":@"$200",@"title":@"Bags"},@{@"price":@"$40",@"title":@"Watches"},@{@"price":@"$1000",@"title":@"Earrings"}] mutableCopy]; 

    NSSortDescriptor *priceDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"" 
                   ascending:YES 
                   comparator:^NSComparisonResult(NSDictionary *dict1, NSDictionary *dict2) { 
                    return [dict1[@"price"] compare:dict2[@"price"] options:NSNumericSearch]; 
    }]; 

    NSSortDescriptor *titleDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"title" ascending:YES]; 



    [arrayProducts sortUsingDescriptors:@[priceDescriptor,titleDescriptor]]; 

    NSLog(@"SortedArray : %@",arrayProducts);