Question

我已经使用NSMutableArray的各种排序方法查看了一些答案，但出于某种原因，它们并不适用于我。

我只是试图通过每个字典中的Delay键对包含字典的可变数组进行排序。但是，“sorted”数组与原始数组完全相同。

顺便说一下，如果我创建一个虚拟可变数组并使用包含数字的字典填充它，它可以正常工作，但由于某种原因它不会对我正在初始化的这个可变数组进行排序。

我做错了什么？

这是我的代码：

playlistCalls = [[NSMutableArray alloc] initWithArray:[currentPlaylist objectForKey:@"Tunes"]];

NSLog(@"original %@", playlistCalls);

NSSortDescriptor *delay = [NSSortDescriptor sortDescriptorWithKey:@"Delay" ascending:YES];
[playlistCalls sortUsingDescriptors:[NSArray arrayWithObject:delay]];

NSLog(@"sorted %@", playlistCalls);

这是包含词典的数组：

2012-06-04 15:48:09.129 MyApp[57043:f503] original (
        {
        Name = Test Tune;
        Delay = 120;
        Volume = 100;
    },
        {
        Name = Testes;
        Delay = 180;
        Volume = 100;
    },
        {
        Name = Testing;
        Delay = 60;
        Volume = 100;
    }
)

2012-06-04 15:48:09.129 MyApp[57043:f503] sorted (
        {
        Name = Test Tune;
        Delay = 120;
        Volume = 100;
    },
        {
        Name = Testes;
        Delay = 180;
        Volume = 100;
    },
        {
        Name = Testing;
        Delay = 60;
        Volume = 100;
    }
)

Answer 1

当我在字典中使用NSNumber时，上面的代码很好。这让我相信Delay值在字典中存储为字符串。您需要做的是按字符串integerValue排序。

NSSortDescriptor *delay = 
   [NSSortDescriptor sortDescriptorWithKey:@"Delay.integerValue" ascending:YES];

Answer 2

请尝试以下操作，它与我合作

NSDictionary *dic;
NSMutableArray *arr = [[NSMutableArray alloc] init];

dic = [NSDictionary dictionaryWithObjectsAndKeys:
        [NSNumber numberWithInt:120], @"Delay",
        [NSNumber numberWithInt:100], @"Volume",
       nil];
[arr addObject:dic];

dic = [NSDictionary dictionaryWithObjectsAndKeys:
       [NSNumber numberWithInt:160], @"Delay",
       [NSNumber numberWithInt:100], @"Volume",
       nil];
[arr addObject:dic];

dic = [NSDictionary dictionaryWithObjectsAndKeys:
       [NSNumber numberWithInt:100], @"Delay",
       [NSNumber numberWithInt:100], @"Volume",
       nil];
[arr addObject:dic];

NSSortDescriptor *sortDesc = [[NSSortDescriptor alloc] initWithKey:@"Delay" ascending:YES];
[arr sortUsingDescriptors:[NSArray arrayWithObject:sortDesc]];

按字典键排序可变数组

2 个答案: