밑줄 텍스트-글꼴 크기가 다른 교차 범위의 선 두께

iOS 7에서는 텍스트 시스템 개체를 만들고 원하는 밑줄을 그리는 작은 샘플 NSLayoutManager재정 -drawUnderlineForGlyphRange:underlineType:baselineOffset:lineFragmentRect:lineFragmentGlyphRange:containerOrigin:의 하위 클래스를 사용하여 원하는 작업을 수행 할 수 있습니다 .

@implementation ViewController
- (void)viewDidLoad
{
    [super viewDidLoad];

    // setup text handling with our subclass of NSLayoutManager
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithString:@"Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do;"];

    MyLayoutManager *textLayout = [[MyLayoutManager alloc] init];

    [textStorage addLayoutManager:textLayout];

    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:self.view.bounds.size];

    [textLayout addTextContainer:textContainer];
    UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(0,20,self.view.bounds.size.width,self.view.bounds.size.height-20)
                                               textContainer:textContainer];
    [self.view addSubview:textView];

    // setup test attributes
    UIFont *font = [UIFont fontWithName:@"TimesNewRomanPSMT" size:15];

    NSMutableDictionary *attributesToSetDict = [NSMutableDictionary dictionary];

    [attributesToSetDict setObject:font forKey:NSFontAttributeName];
    [attributesToSetDict setObject:[UIColor blueColor] forKey:NSForegroundColorAttributeName];
    [attributesToSetDict setObject:@1 forKey:NSUnderlineStyleAttributeName];

    [textView.textStorage setAttributes:attributesToSetDict range:NSMakeRange(9, 28)];

    UIFontDescriptor *fontDescriptor = [font fontDescriptor];
    attributesToSetDict = [NSMutableDictionary dictionary];
    [attributesToSetDict setObject:[UIFont fontWithDescriptor:fontDescriptor size:25] forKey:NSFontAttributeName];
    [attributesToSetDict setObject:[UIColor redColor] forKey:NSForegroundColorAttributeName];
    [attributesToSetDict setObject:@1 forKey:NSUnderlineStyleAttributeName];

    [textView.textStorage setAttributes:attributesToSetDict range:NSMakeRange(26, 7)];
}
@end

@implementation MyLayoutManager
- (void)drawUnderlineForGlyphRange:(NSRange)glyphRange underlineType:(NSUnderlineStyle)underlineVal baselineOffset:(CGFloat)baselineOffset lineFragmentRect:(CGRect)lineRect lineFragmentGlyphRange:(NSRange)lineGlyphRange containerOrigin:(CGPoint)containerOrigin
{
    /* For the sample we consider that underlineVal is equals to NSUnderlineStyleSingle */

    /*
     * We need to create a CTFontRef as UIFont doesn't provided 'Underline Position' and 'Underline Thickness'
     */

    // get current UIFont for the glyphRange
    NSRange characterRange = [self characterRangeForGlyphRange:glyphRange actualGlyphRange:NULL];
    UIFont *font = [[self.textStorage attributesAtIndex:characterRange.location effectiveRange:NULL] objectForKey:NSFontAttributeName];

    CTFontRef ctfont = CTFontCreateWithName((CFStringRef)[font fontName], [font pointSize], NULL);

    CGPoint startLocation = [self locationForGlyphAtIndex:glyphRange.location];
    CGPoint endLocation = [self locationForGlyphAtIndex:NSMaxRange(glyphRange)];

    CGContextRef ctx = UIGraphicsGetCurrentContext();

    // -underlineGlyphRange:underlineType:lineFragmentRect:lineFragmentGlyphRange:containerOrigin: already set color and line width
    // for the current context

    // reset line width with current font underline thickness
    CGContextSetLineWidth(ctx, CTFontGetUnderlineThickness(ctfont));

    CGContextMoveToPoint(ctx, startLocation.x + containerOrigin.x, startLocation.y + containerOrigin.y - CTFontGetUnderlinePosition(ctfont));
    CGContextAddLineToPoint(ctx, endLocation.x + containerOrigin.x, endLocation.y + containerOrigin.y - CTFontGetUnderlinePosition(ctfont));

    CGContextStrokePath(ctx);

    CFRelease(ctfont);
}