18

我将名称存储为键，将分数存储为值，NSDictionary以保存在NSUserDefaults. 然后我想取回按分数排序的键，但我似乎无法按数字对它们进行排序，只能按字符串。例如，分数 100、50、300、200、500 的列表给了我 100、200、300、50、500。

可以这样做还是我需要以不同的方式去做？

NSString *defaultNames[] = {@"Matt", @"Terry",@"Jessica",@"Sean",nil};
NSNumber *defaultScores[] = {@"600", @"500",@"100",@"50", nil};

NSDictionary *newScoreDict =  [NSDictionary dictionaryWithObjects:(id *)defaultScores forKeys:(id *)defaultNames count:7];

NSArray *currScores = [scoreDict keysSortedByValueUsingSelector:@selector(compare:)];
4

6 回答 6

7

如何使用 keysSortedByValueUsingSelector (NSDictionary)

根据 XCode 中的文档，这似乎是您所需要的

于 2010-01-07T16:01:08.280 回答
5 
NSString *defaultNames[] = {@"Matt", @"Terry",@"Jessica",@"Sean",nil};
NSNumber *defaultScores[] = {@"600", @"500",@"100",@"50", nil};
NSDictionary *newScoreDict =  [NSDictionary dictionaryWithObjects:(id *)defaultScores forKeys:(id *)defaultNames count:7];
NSArray *currScores = [scoreDict keysSortedByValueUsingSelector:@selector(localizedStandardCompare:)];
于 2012-08-16T10:25:11.470 回答
3 
@implementation NSString (numericComparison)

- (NSComparisonResult) floatCompare:(NSString *) other
{
    float myValue = [self floatValue];
    float otherValue = [other floatValue];
    if (myValue == otherValue) return NSOrderedSame;
    return (myValue < otherValue ? NSOrderedAscending : NSOrderedDescending);
}

- (NSComparisonResult) intCompare:(NSString *) other
{
    int myValue = [self intValue];
    int otherValue = [other intValue];
    if (myValue == otherValue) return NSOrderedSame;
    return (myValue < otherValue ? NSOrderedAscending : NSOrderedDescending);
}

@end

NSString *defaultNames[] = {@"Matt", @"Terry",@"Jessica",@"Sean",nil};
// NSNumber *defaultScores[] = {@"600", @"500",@"100",@"50", nil};

NSNumber *defaultScores[] = {                                                                   
            [NSNumber  numberWithInt:600],
            [NSNumber  numberWithInt:500],
            [NSNumber  numberWithInt:100],
            [NSNumber  numberWithInt:50],
            nil 
    };

NSDictionary *newScoreDict =  [NSDictionary dictionaryWithObjects:(id *)defaultScores forKeys:(id *)defaultNames count:4];

NSArray *currScores = [newScoreDict keysSortedByValueUsingSelector:@selector(intCompare:NotSureWhatGoesHere:)];

我仍然对上一行感到困惑？

我只是用 

//
NSArray *currScores = [newScoreDict keysSortedByValueUsingSelector:@selector(intCompare:other:)];
//

数字数组可以吗，还是有更简单的方法？

非常感谢您...

于 2010-03-04T05:08:39.790 回答
2

-compare：是一个字符串比较。通过不同的方法进行比较，例如：

@implementation NSString (numericComparison)

- (NSComparisonResult) compareNumerically:(NSString *) other
{
float myValue = [self floatValue];
float otherValue = [other floatValue];
if (myValue == otherValue) return NSOrderedSame;
return (myValue < otherValue ? NSOrderedAscending : NSOrderedDescending);
}

@end

在您的特定情况下，您可以改用 -intValue 。

于 2009-10-25T06:09:22.293 回答
0

不确定它会有所帮助，但您也可以将 NSArray 保存在 plist 中；与 NSDictionary 不同（它以基本上随机的顺序返回键），您可以在放入它们时将它们取回。

于 2009-10-26T05:11:11.747 回答
0

我认为这个问题最简单的方法是使用比较器..

NSString *defaultNames[] = {@"Matt", @"Terry",@"Jessica",@"Sean",nil};
NSNumber *defaultScores[] = {@(600), @(500),@(400),@(50), nil};
NSDictionary *newScoreDict =  [NSDictionary dictionaryWithObjects:defaultNames       forKeys:defaultScores count:4];
NSArray *currScores = [newScoreDict keysSortedByValueUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    if ([obj1 integerValue] > [obj2 integerValue]) {
        return NSOrderedAscending;
    }else{
        return NSOrderedDescending;
    }}];

for (NSString *string in currScores) {
    NSLog(@"%@",string);
}

试试这个.. 我注意到我无法通过使用 NSNumber 对象来达到价值，所以如果你想达到对象价值，我可以通过将你的 NSNumber 分数更改为 NSString 并在订购时将它们转换为数字来解决。你可以像下面这样使用..

NSString *defaultNames[] = {@"Matt", @"Terry",@"Jessica",@"Sean",nil};
NSString *defaultScores[] = {@"600", @"500",@"400",@"50", nil};
NSMutableDictionary *newScoreDict =  [NSMutableDictionary   dictionaryWithObjects:defaultScores  forKeys:defaultNames count:4];

NSArray *currScores = [newScoreDict keysSortedByValueUsingComparator:^NSComparisonResult(id obj1, id obj2) {
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
NSNumber *number1 = [formatter numberFromString:obj1];
NSNumber *number2 = [formatter numberFromString:obj2];
    if (number1.intValue > number2.intValue) {
        return NSOrderedDescending;
    }else{
        return NSOrderedAscending;
    }}];

for (NSString *name in currScores) {
    NSLog(@"key %@ value %@",name,[newScoreDict valueForKey:name]);
}

希望能帮助到你..

于 2014-05-29T22:26:33.890 回答