ios - 按升序对数组进行排序并删除 objective-c 中的重复值

Question

我有一个可水平和垂直滚动的表格。我从 Web 服务 (json) 获取标题和第一列的数据。我想按升序对数据进行排序，并从标题和第一列中删除重复数据。为了删除重复值，我使用了以下代码:

-(void) requestFinished: (ASIHTTPRequest *) request
{
    NSString *theJSON = [request responseString];

    SBJsonParser *parser = [[SBJsonParser alloc] init];

    NSMutableArray *jsonDictionary = [parser objectWithString:theJSON error:nil];

    headData = [[NSMutableArray alloc] init];
    NSMutableArray *head = [[NSMutableArray alloc] init];

    leftTableData = [[NSMutableArray alloc] init];
    NSMutableArray *left = [[NSMutableArray alloc] init];

    rightTableData = [[NSMutableArray alloc]init];

    for (NSMutableArray *dictionary in jsonDictionary)
    {
        Model *model = [[Model alloc]init];

        model.cid = [[dictionary valueForKey:@"cid"]intValue];
        model.iid = [[dictionary valueForKey:@"iid"]intValue];
        model.yr = [[dictionary valueForKey:@"yr"]intValue];
        model.val = [dictionary valueForKey:@"val"];

        [mainTableData addObject:model];

        [head addObject:[NSString stringWithFormat:@"%ld", model.yr]];
        [left addObject:[NSString stringWithFormat:@"%ld", model.iid]];
    }
    NSOrderedSet *orderedSet = [NSOrderedSet orderedSetWithArray:head];
    headData = [[orderedSet array] mutableCopy];

//    NSSet *set = [NSSet setWithArray:left];
//    NSArray *array2 = [set allObjects];
//    NSLog(@"%@", array2);

    NSOrderedSet *orderedSet1 = [NSOrderedSet orderedSetWithArray:left];
    NSMutableArray *arrLeft = [[orderedSet1 array] mutableCopy];

    //remove duplicate enteries from header array
    [leftTableData addObject:arrLeft];


    NSMutableArray *right = [[NSMutableArray alloc]init];
    for (int i = 0; i < arrLeft.count; i++)
    {
        NSMutableArray *array = [[NSMutableArray alloc] init];
        for (int j = 0; j < headData.count; j++)
        {
            /* NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF.iid == %ld", [[arrLeft objectAtIndex:i] intValue]];
             NSArray *filteredArray = [mainTableData filteredArrayUsingPredicate:predicate];*/
            NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF.iid == %ld AND SELF.yr == %ld", [[arrLeft objectAtIndex:i] intValue], [[headData objectAtIndex:j] intValue]];
            NSArray *filteredArray = [mainTableData filteredArrayUsingPredicate:predicate];

            if([filteredArray count]>0)
            {
                Model *model = [filteredArray objectAtIndex:0];
                [array addObject:model.val];
            }
        }
        [right addObject:array];
    }
    [rightTableData addObject:right];
}

如何对数组进行升序排序？

请帮忙。

Answer 1

好的，所以你有一个看起来像这样的模型对象......

@interface Model: NSObject

@property NSNumber *idNumber;
@property NSNumber *year;
@property NSString *value;

@end

请注意，我故意使用 NSNumber 而不是 NSInteger 的原因将会变得很清楚。

目前您正试图在一个地方做很多事情。不要这样做。

创建一个新对象来存储这些数据。然后您可以添加方法来获取您需要的数据。看到您在按年份划分的表格 View 中显示，然后每个部分按 idNumber 排序，那么我会做这样的事情......

@interface ObjectStore: NSObject

- (void)addModelObject:(Model *)model;

// standard table information
- (NSInteger)numberOfYears;
- (NSInteger)numberOfIdsForSection:(NSinteger)section;

// convenience methods
- (NSNumber *)yearForSection:(NSInteger)section;
- (NSNumber *)idNumberForSection:(NSInteger)section row:(NSInteger)row;
- (NSArray *)modelsForSection:(NSInteger)section row:(NSInteger)row;

// now you need a way to add objects
- (void)addModelObject:(Model *)model;

@end

现在开始实现。

我们要将所有内容存储在一本字典中。键是 years，对象是字典。在这些字典中，键是 idNumbers，对象是数组。这些数组将保存模型。

像这样...

{
    2010 : {
        1 : [a, b, c],
        3 : [c, d, e]
    },
    2013 : {
        1 : [g, h, u],
        2 : [e, j, s]
    }
}

我们还将使用所有便捷方法来完成此操作。

@interface ObjectStore: NSObject

@property NSMutableDictionary *objectDictionary;

@end

@implementation ObjectStore

 + (instancetype)init
{
    self = [super init];

    if (self) {
        self.objectDictionary = [NSMutableDictionary dictionary];
    }

    return self;
}

 + (NSInteger)numberOfYears
{
    return self.objectDictionary.count;
}

 + (NSInteger)numberOfIdsForSection:(NSinteger)section
{
    // we need to get the year for this section in order of the years.
    // lets create a method to do that for us.
    NSNumber *year = [self yearForSection:section];

    NSDictionary *idsForYear = self.objectDictionary[year];

    return idsForYear.count;
}

- (NSNumber *)yearForSection:(NSInteger)section
{
    // get all the years and sort them in order
    NSArray *years = [[self.obejctDictionary allKeys] sortedArrayUsingSelector:@selector(compare:)];

    // return the correct year
    return years[section];
}

- (NSNumber *)idNumberForSection:(NSInteger)section row:(NSInteger)row
{
    // same as the year function but for id
    NSNumber *year = [self yearForSection:section];

    NSArray *idNumbers = [[self.objectDictionary allKeys]sortedArrayUsingSelector:@selector(compare:)];

    return idNumbers[row];
}

- (NSArray *)modelsForSection:(NSInteger)section row:(NSInteger)row
{
    NSNumber *year = [self yearForSection:section];
    NSNumber *idNumber = [self idForSection:section row:row];

    return self.objectDictionary[year][idNumber];
}

// now we need a way to add objects that will put them into the correct place.

- (void)addModelObject:(Model *)model
{
    NSNumber *modelYear = model.year;
    NSNumber *modelId = model.idNumber;

    // get the correct storage location out of the object dictionary
    NSMutableDictionary *idDictionary = [self.objectDictionary[modelYear] mutableCopy];

    // there is a better way to do this but can't think atm
    if (!idDictionary) {
        idDictionary = [NSMutableDictionary dictionary];
    }

    NSMutableArray *modelArray = [idDictionary[modelId] mutableCopy];

    if (!modelArray) {
        modelArray = [NSMutableArray array];
    }

    // insert the model in the correct place.
    [modelArray addObject:model];
    idDictionary[modelId] = modelArray;
    self.objectDictionary[modelYear] = idDictionary;
}

@end

完成所有这些设置后，您现在可以用这个替换您的复杂函数...

-(void) requestFinished: (ASIHTTPRequest *) request
{
    NSString *theJSON = [request responseString];
    SBJsonParser *parser = [[SBJsonParser alloc] init];
    NSDictionary *jsonDictionary = [parser objectWithString:theJSON error:nil];

    for (NSDictionary *dictionary in jsonDictionary)
    {
        Model *model = [[Model alloc]init];

        model.cid = [dictionary valueForKey:@"cid"];
        model.idNumber = [dictionary valueForKey:@"iid"];
        model.year = [dictionary valueForKey:@"yr"];
        model.val = [dictionary valueForKey:@"val"];

        [self.objectStore addModelObject:model];
    }
}

要获取特定行的模型，只需使用...

[self.objectStore modelsForSection:indexPath.section row:indexPath.row];

要在 tableview 委托(delegate)方法中获取部分的数量...

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return [self.objectStore numberOfYears];
}

不要乱用 View Controller 中的模型。

欢迎使用 MVC 模式。

此处有大量代码，但通过将所有代码放在此处，您可以从 VC 中删除所有复杂代码。