iOS 使用UILocalizedIndexedCollatio

作者: 困惑困惑困惑 | 来源:发表于2018-04-11 15:41 被阅读55次

原文链接：http://www.cnblogs.com/pretty-guy/p/4831586.html
　UITableView在行数相当多的时候，给人的感觉是非常笨重的。通常为了方便用户使用，采用的方法有：搜索框、按层级展示、区域索引标题。

前两种就不用介绍了，此文就介绍区域索引标题的实现。

区域索引标题可以在通讯录里看到，类似这样：

image

区域索引标题可以通过转拼音实现，本文主要介绍使用UILocalizedIndexedCollation实现区域索引标题

UILocalizedIndexedCollation是苹果贴心为开发者提供的排序工具，会自动根据不同地区生成索引标题

<pre style="margin: 0px; padding: 0px; white-space: pre-wrap; word-wrap: break-word; font-family: "Courier New" !important; font-size: 12px !important;">//根据SEL方法返回的字符串判断对象应该处于哪个分区

(NSInteger)sectionForObject:(id)object collationStringSelector:(SEL)selector; //根据SEL方法返回的string对数组元素排序
(NSArray *)sortedArrayFromArray:(NSArray *)array collationStringSelector:(SEL)selector;</pre>

具体使用方法如下：

1.构造数据源

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<pre style="margin: 0px; padding: 0px; white-space: pre-wrap; word-wrap: break-word; font-family: "Courier New" !important; font-size: 12px !important;">NSArray *testArr = @[@"悟空",@"沙僧",@"八戒", @"吴进", @"悟能", @"唐僧", @"诸葛亮", @"赵子龙",@"air", @"Asia", @"crash", @"basic", @"阿里郎"];

NSMutableArray *personArr = [NSMutableArray arrayWithCapacity:testArr.count]; for (NSString *str in testArr) {
    Person *person = [[Person alloc] initWithName:str];
    [personArr addObject:person];
}

UILocalizedIndexedCollation *collation = [UILocalizedIndexedCollation currentCollation];
NSLog(@"%@", collation.sectionTitles); //1.获取获取section标题
NSArray *titles = collation.sectionTitles; //2.构建每个section数组
NSMutableArray *secionArray = [NSMutableArray arrayWithCapacity:titles.count]; for (int i = 0; i < titles.count; i++) {
    NSMutableArray *subArr = [NSMutableArray array];
    [secionArray addObject:subArr];
} //3.排序 //3.1 按照将需要排序的对象放入到对应分区数组
for (Person *person in personArr) {
    NSInteger section = [collation sectionForObject:person collationStringSelector:@selector(name)];
    NSMutableArray *subArr = secionArray[section];

    [subArr addObject:person];
} //3.2 分别对分区进行排序
for (NSMutableArray *subArr in secionArray) {
    NSArray *sortArr = [collation sortedArrayFromArray:subArr collationStringSelector:@selector(name)];
    [subArr removeAllObjects];
    [subArr addObjectsFromArray:sortArr];
}</pre>

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2.实现TableViewDataSource

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<pre style="margin: 0px; padding: 0px; white-space: pre-wrap; word-wrap: break-word; font-family: "Courier New" !important; font-size: 12px !important;">#pragma mark SectionTitles

(NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{ return [[[UILocalizedIndexedCollation currentCollation] sectionTitles] objectAtIndex:section];
} - (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView
{ return [[UILocalizedIndexedCollation currentCollation] sectionIndexTitles];
} - (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index
{ return [[UILocalizedIndexedCollation currentCollation] sectionForSectionIndexTitleAtIndex:index];
}</pre>

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