iOS tabview如何添加字母索引

//系统获取首字母- (NSString *) pinyinFirstLetter:(NSString*)sourceString { NSMutableString *source = [sourceString mutableCopy]; CFStringTransform((__bridge CFMutableStringRef)source, NULL, kCFStringTransformMandarinLatin, NO); CFStringTransform((__bridge CFMutableStringRef)source, NULL, kCFStringTransformStripDiacritics, NO);//这一行是去声调的 return source;}

#import "ViewController.h"#import "BMChineseSort.h"#import "Person.h"@interface ViewController (){ NSMutableArray<Person *> *dataArray;}//排序后的出现过的拼音首字母数组@property(nonatomic,strong)NSMutableArray *indexArray;//排序好的结果数组@property(nonatomic,strong)NSMutableArray *letterResultArr;@end@implementation ViewController- (void)viewDidLoad { [super viewDidLoad]; //模拟数据加载 dataArray中得到Person的数组 [self loadData]; //BMChineseSort 文件包含两个对单元格数据和右侧字母的数组排序函数 //根据Person对象的 name 属性 按中文 对 Person数组 排序 //每一个单元格的数据，排序好了的 self.indexArray = [BMChineseSort IndexWithArray:dataArray Key:@"name"]; //左侧的字母数组，已经排序好了 self.letterResultArr = [BMChineseSort sortObjectArray:dataArray Key:@"name"]; UITableView *table = [[UITableView alloc] initWithFrame:self.view.frame]; table.delegate = self; table.dataSource = self; [self.view addSubview:table];}//加载模拟数据-(void)loadData{ NSArray *stringsToSort=[NSArray arrayWithObjects:       @"李白",@"张三",       @"重庆",@"重量",       @"调节",@"调用",       @"小白",@"小明",@"千珏",       @"黄家驹", @"鼠标",@"hello",@"多美丽",@"肯德基",@"##",       nil]; //模拟网络请求接收到的数组对象 Person数组 dataArray = [[NSMutableArray alloc] initWithCapacity:0]; for (int i = 0; i<[stringsToSort count]; i++) {  Person *p = [[Person alloc] init];  p.name = [stringsToSort objectAtIndex:i];  p.number = i;  [dataArray addObject:p]; }}#pragma mark - UITableView -//section的titleHeader- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { return [self.indexArray objectAtIndex:section];}//section行数-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{ return [self.indexArray count];}//每组section个数- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{ return [[self.letterResultArr objectAtIndex:section] count];}//section右侧index数组-(NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView{ return self.indexArray;}//点击右侧索引表项时调用 索引与section的对应关系- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index{ return index;}//返回cell- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{ UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CELL"]; if (cell == nil){  cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CELL"]; } //获得对应的Person对象<替换为你自己的model对象> Person *p = [[self.letterResultArr objectAtIndex:indexPath.section] objectAtIndex:indexPath.row]; cell.textLabel.text = p.name; return cell;}@end