iOS 生成索引

首先生成索引字典

• 其中所有key值即为分区的大写字母

• value值为一个个数组,每个分区的数据

#pragma mark --- 生成索引字典
-(NSDictionary *) indexDictionaryBySortArray:(NSMutableArray *)marray withObjectKey:(NSString *)akey
{
    
//    [self sortArray:marray withObjectKey:akey];
    
    QiLa_FamousEditFrameSet *frameSet = nil;
    NSMutableDictionary * dic = [[NSMutableDictionary alloc] init];
    
    if ([akey isEqualToString:@"nickName"])
    {
        for (int i=0; i<[marray count]; i++)
        {
            frameSet = [marray objectAtIndex:i];
            NSString * first = nil;
            NSString * str = @"^[A-Za-z]+.*[\u4e00-\u9fa5]*";
            NSPredicate * pre = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",str];
            if ([pre evaluateWithObject:frameSet.famousModel.nickName]) {
                first = [[frameSet.famousModel.nickName substringToIndex:1] uppercaseString];
            }else{
                NSString * abcStr = [NSString stringWithFormat:@"%@",frameSet.famousModel.nickName];
                
                NSString * str1 = @"^[\u4e00-\u9fa5]+.*[A-Za-z]*";
                NSPredicate * pre1 = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",str1];
                if (![abcStr isEqualToString:@""] && ![abcStr isKindOfClass:[NSNull class]] && abcStr) {
                    if ([pre1 evaluateWithObject:abcStr]) {
                        unichar firstChar = [abcStr characterAtIndex:0];
                        first = [[NSString stringWithFormat:@"%c", pinyinFirstLetter((unsigned short)firstChar)] uppercaseString];
                        
                    }else {
                        first = @"#";
                    }
                }else{
                    first = @"#";
                }
                
            }
            
            if (!dic) {
                NSMutableArray *arr = [NSMutableArray array];
                [arr addObject:frameSet];
                [dic setObject:arr forKey:first];
            }else if ([[dic allKeys] containsObject:first]){
                
                [[dic objectForKey:first] addObject:frameSet];
                
            }else{
                NSMutableArray * arr = [NSMutableArray array];
                [arr addObject:frameSet];
                [dic setObject:arr forKey:first];
            }
        }
    }
    
    return dic;
}

对所有的key值排序

[self.sectionTitles sortUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {
        NSString * s1 = (NSString *) obj1;
        NSString * s2 = (NSString *) obj2;
        return [s1 localizedCompare:s2];
    }];

self.sectionTitles是一个排完序之后的数组,也就是数据源,给tableView所有代理赋值