문장에서 문자열을 검색하는 단계

-(NSArray*)searchWordWithRange:(NSString*)targetText word:(NSString*)
searchWord
{
    //! rangeオブジェクト(NSValue)の格納配列
    NSMutableArray* arrayRangeValue = [[NSMutableArray alloc] init];
    //! range初期化
    NSRange range = NSMakeRange(0, targetText.length);
    //! targetTextから検索 見つからなかったらwhile文を抜ける
    while ([targetText rangeOfString:searchWord options:NSLiteralSearch
                               range:range].location != NSNotFound) {
        //! 発見したrange
        NSRange rangeDetect = [targetText rangeOfString:searchWord
                                                options:NSLiteralSearch range:range];
        //! NSRangeをNSValueに変換
        [arrayRangeValue addObject:[NSValue valueWithRange:rangeDetect]];
        //! rangeのオフセット変更
        range = NSMakeRange(rangeDetect.location+rangeDetect.length,
                            targetText.length - (rangeDetect.location+rangeDetect.length));
    }
    return arrayRangeValue;
}

NSRange(NSValue)를 포함한 배열과 텍스트 본문을 인수로 하여 색을 붙이는 함수

-(NSAttributedString*)highlightStringByRanges:(NSString*)targetText
                                       ranges:(NSArray*)arrayRange
{
    NSMutableAttributedString* stringAttributed = [[
                                                    NSMutableAttributedString alloc] initWithString:targetText

                                                   attributes:nil];
    for (NSValue* rangeObject in arrayRange) {
        NSRange range = [rangeObject rangeValue];
        [stringAttributed addAttribute:NSBackgroundColorAttributeName 
                                 value:[UIColor cyanColor] range:range];
    }
    return stringAttributed;
}

ViewDidLoad에서 위의 두 가지 메서드 호출

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    NSBundle* bundle = [NSBundle mainBundle];
    //! 青空文庫の「こころ」を取得
    NSString* stringPath = [bundle pathForResource:@"kokoro" ofType:@"txt"];
    NSString* stringText = [NSString stringWithContentsOfFile:stringPath encoding:NSShiftJISStringEncoding error:nil];
    //! "私"を検索
    NSArray* arrayRange = [self searchWordWithRange:stringText word:@"私"];
    //! UITextViewのattributedTextに設定すること
    _textview.attributedText = [self highlightStringByRanges:stringText ranges:arrayRange];

}

나츠메 소세키의 "마음"에서 "나"를 검색 한 결과