NSAttributedStringを使ってリンク文字を作る

gistfile1.m

#import "YMNViewController.h"

NSString *const Text = @"The iOS Developer Program provides a complete and integrated process for developing and distributing iOS apps on the App Store. Learn more";
NSString *const LinkText = @"Learn more";

@interface YMNViewController ()

@property (nonatomic, strong) UITextView *textView;
@property (nonatomic, strong) UITapGestureRecognizer *tapGesture;

@end

@implementation YMNViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	
    self.textView = [[UITextView alloc] initWithFrame:CGRectMake(0.f, 20.f, self.view.frame.size.width, self.view.frame.size.height)];
    self.textView.userInteractionEnabled = YES;
    self.textView.editable = NO;
    
    // AttributedStringでリンクっぽく装飾する
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:Text];
    NSRange link = [Text rangeOfString:LinkText];
    [attributedString addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:link];
    [attributedString addAttribute:NSUnderlineStyleAttributeName value:@(NSUnderlineStyleSingle) range:link];
    self.textView.attributedText = attributedString;
    
    // UITapGestureRecognizerをセットしてタップされた文字の位置を取得できるようにする
    self.tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapText:)];
    [self.textView addGestureRecognizer:self.tapGesture];
    
    [self.view addSubview:self.textView];
    
}

- (void)tapText:(UITapGestureRecognizer*)tap {
    // タップされた座標をもとに最寄りの文字列の位置を取得
    CGPoint location = [tap locationInView:self.textView];
    UITextPosition *textPosition = [self.textView closestPositionToPoint:location];
    
    // テキストの先頭とタップした文字の距離をNSIntegerで取得
    NSInteger selectedPosition = [self.textView offsetFromPosition:_textView.beginningOfDocument toPosition:textPosition];
    NSRange linkRange = [Text rangeOfString:LinkText];
    
    // タップした文字がリンク文字のrangeに含まれるか判定
    if (NSLocationInRange (selectedPosition,linkRange)) {
        NSLog(@"Learn more");
    }
}

@end