iOS 开发 排序问题 （好友列表，按字母排序）

iOS 开发 排序问题 （好友列表，按字母排序）

一、预备工作

①好友数据模型展示

FriendModel

@property(nonatomic,copy)NSString *photo;
@property(nonatomic,copy)NSString *userName;
@property(nonatomic,copy)NSString *userId;
@property(nonatomic,copy)NSString *phoneNO;

我们用userName的首字母排序；

② 存放model的数组 dataSource

③存放所有首字母的数组 lettersArray

④存放首字母对应字典， nameDic 字典中内容为该字母下的model数组

二、 下面是排序方法

- (void)handleLettersArray
{
NSMutableDictionary *tempDic = [[NSMutableDictionary alloc]init];

for(FriendModel *friends  in dataSource)//①、②
{
HanyuPinyinOutputFormat *formatter =  [[HanyuPinyinOutputFormat alloc] init];
formatter.caseType = CaseTypeLowercase;
formatter.vCharType = VCharTypeWithV;
formatter.toneType = ToneTypeWithoutTone;

NSString *outputPinyin=[PinyinHelper toHanyuPinyinStringWithNSString:friends.userName withHanyuPinyinOutputFormat:formatter withNSString:@""];
NSLog(@"%@",[[outputPinyin substringToIndex:1] uppercaseString]);
[tempDic setObject:friends forKey:[[outputPinyin substringToIndex:1] uppercaseString]];
}

self.lettersArray = tempDic.allKeys;//③

for (NSString *letter in self.lettersArray) {
NSLog(@"letter==%@",letter);
NSMutableArray *tempArry = [[NSMutableArray alloc] init];

for (NSInteger i = 0; i<dataSource.count; i++) {
FriendModel *friends = dataSource[i];
NSLog(@"name = %@",friends.userName);

HanyuPinyinOutputFormat *formatter =  [[HanyuPinyinOutputFormat alloc] init];
formatter.caseType = CaseTypeUppercase;
formatter.vCharType = VCharTypeWithV;
formatter.toneType = ToneTypeWithoutTone;

NSString *outputPinyin=[PinyinHelper toHanyuPinyinStringWithNSString:friends.userName withHanyuPinyinOutputFormat:formatter withNSString:@""];
NSLog(@"%@",[[outputPinyin substringToIndex:1] uppercaseString]);
if ([letter isEqualToString:[[outputPinyin substringToIndex:1] uppercaseString]]) {
[tempArry addObject:friends];

}

}
[self.nameDic setObject:tempArry forKey:letter];// ④
//        NSLog(@"tempArry==%@",tempArry);
}

self.lettersArray = tempDic.allKeys;
//    NSLog(@"%@",self.lettersArray);

NSComparator cmptr = ^(id obj1, id obj2){
if ([obj1 characterAtIndex:0] > [obj2 characterAtIndex:0]) {
return (NSComparisonResult)NSOrderedDescending;
}

if ([obj1 characterAtIndex:0] < [obj2 characterAtIndex:0]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
};

self.lettersArray = [[NSMutableArray alloc]initWithArray:[self.lettersArray sortedArrayUsingComparator:cmptr]];
NSLog(@"%@",self.lettersArray);
}

三、用法

做tableView时，用letterArray确定分组数，取出key，用key从nameDic中取出该组的model。