#import <UIKit/UIKit.h>

@interface TextKit01ViewController : UIViewController

@property (nonatomic,strong) IBOutlet UITextView *textView;
// 文本可以排版的区域
@property (nonatomic,strong) NSTextContainer *textContainer;
// 设置文本风格
- (void) markWord:(NSString*)word inTextStorage:(NSTextStorage*)textStorage;

@end

#import "TextKit01ViewController.h"

@interface TextKit01ViewController ()

@end

@implementation TextKit01ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    CGRect textViewRect = CGRectInset(self.view.bounds, 10.0, 20.0);
    
    // 1、创建储存文本对象textStorage
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithString:self.textView.text];
    
    // 2、创建文字排版对象layoutManager
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    
    // 3、创建文本排版的区域textContainer
    self.textContainer = [[NSTextContainer alloc] initWithSize:textViewRect.size];
    
    // 4、设置textStorage与layoutManager的关系
    [textStorage addLayoutManager:layoutManager];
    
    // 5、设置layoutManager与textContainer的关系
    [layoutManager addTextContainer:self.textContainer];
    
    // 6、重新构建原来的textview控件
    [self.textView removeFromSuperview];
    self.textView = [[UITextView alloc] initWithFrame:textViewRect textContainer:self.textContainer];
    [self.view addSubview:self.textView];
    
    // 7、设置textStorage中文本的风格
    [textStorage beginEditing];
    
    NSDictionary *attrsDic = @{NSTextEffectAttributeName:NSTextEffectLetterpressStyle};
    NSMutableAttributedString *attrStr = [[NSMutableAttributedString alloc] initWithString:self.textView.text attributes:attrsDic];
    [textStorage setAttributedString:attrStr];
    
    [self markWord:@"我" inTextStorage:textStorage];
    [self markWord:@"I" inTextStorage:textStorage];
    
    [textStorage endEditing];
    
}

-(void)markWord:(NSString *)word inTextStorage:(NSTextStorage *)textStorage
{
    // 1、创建正则表达式regex
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:word options:0 error:nil];
    
    // 2、扫描textStorage中的文本
    NSArray *matches = [regex matchesInString:self.textView.text options:0 range:NSMakeRange(0, [self.textView.text length])];
    
    // 3、为找到的文本内容设置风格
    for (NSTextCheckingResult *match in  matches) {
        NSRange matchRange = [match range];
        [textStorage addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:matchRange];
    }
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end