UILocalizedIndexedCollation通讯录分组

UILocalizedIndexedCollation 可以对数组重建索引，按照首字母顺序进行排序。

LCIndexTool.h

#define kToolsIndexAryKey @"LCIndexAryKey"     //索引
#define kToolsGroupAryKey @"LCGroupAryKey"  //排序后的分组

/**
 对数组排序

 @param mArray      需要排序的数组
 @param proretyName 数组中对象需要排序的属性

 @return 排序后的索引及gourpAry 字典形式 kToolsIndexAryKey kToolsGroupAryKey
 */
+ (NSDictionary *)sortedArrayWithChineseObject:(NSMutableArray *)mArray  withPropertyNameSEL:(SEL)nameSEL ;

proretyName为属性名称例如：
Person 类 属性 ：name age phoneNumber
我们需要根据name的首字母来排序分组 则传递@selector(name)

LCIndexTool.m

//数组排序
+ (NSDictionary *)sortedArrayWithChineseObject:(NSMutableArray *)mArray  withPropertyNameSEL:(SEL)nameSEL {
    
    UILocalizedIndexedCollation *indexCollation = [UILocalizedIndexedCollation currentCollation];
    NSInteger index, sectionTitlesCount = [[indexCollation sectionTitles] count];
    NSMutableArray *suoYinArr = [[NSMutableArray alloc] initWithArray:[indexCollation sectionTitles]];
    
    //临时数据，存放section对应的userObjs数组数据
    NSMutableArray *newSectionsArray = [[NSMutableArray alloc] initWithCapacity:sectionTitlesCount];
    
    //设置sections数组初始化：元素包含userObjs数据的空数据
    for (index = 0; index < sectionTitlesCount; index++) {
        NSMutableArray *array = [[NSMutableArray alloc] init];
        [newSectionsArray addObject:array];
    }
  
    //分组
    for (id object in mArray) {
        //根据timezone的localename，获得对应的的section number
        NSInteger sectionNumber = [indexCollation sectionForObject:object collationStringSelector:nameSEL];
        //根据sectionNumber获取数组
        NSMutableArray *sectionUserObjs = [newSectionsArray objectAtIndex:sectionNumber];
        //添加对象到对应的数组中
        [sectionUserObjs addObject:object];
    }
    
    //获取空的数组的index
    NSMutableArray *willDeleteAry = [NSMutableArray new];
    for (int i = 0; i < newSectionsArray.count; i ++) {
        NSArray *tempAry = newSectionsArray[i];
        if (tempAry.count == 0) {
            [willDeleteAry addObject:[NSString stringWithFormat:@"%d",i]];
        }
    }
    //删除空的数组
    for (NSInteger i = willDeleteAry.count; i > 0; i -- ) {
        NSInteger index = [willDeleteAry[i - 1] integerValue];
        [newSectionsArray removeObjectAtIndex:index];
        [suoYinArr removeObjectAtIndex:index];
    }
    
    //该字典中存放分组排序呢后的索引及数据
    NSDictionary *dict = @{kToolsGroupAryKey:newSectionsArray,kToolsIndexAryKey:suoYinArr};
    

    return dict;

}