Core Text ein bisschen kleiner als NSString drawInRect :?

Question

In der Theorie sollte diese gleich groß sein, aber sie sind nicht:

Der Text in blau von Core-Text ist, in schwarz aus -[NSString drawInRect:] ist. Hier ist der Code:

//Some formatting to get the correct frame 
int y = MESSAGE_FRAME.origin.y + 8; 

    if (month) y = y + 27; 

    int height = [JHomeViewCellContentView heightOfMessage:self.entry.message]; 

    CGRect rect = CGRectMake(MESSAGE_FRAME.origin.x + 8, y, MESSAGE_FRAME.size.width - 16, height); 


    //Draw in rect method 
    UIFont *font = [UIFont fontWithName:@"Crimson" size:15.0f]; 

    [[UIColor colorWithWhite:0.2 alpha:1.0] setFill]; 

    [self.entry.message drawInRect:rect withFont:font lineBreakMode:UILineBreakModeWordWrap alignment:UITextAlignmentLeft]; 



    //Frame change to suit CoreText 
    CGRect rect2 = CGRectMake(MESSAGE_FRAME.origin.x + 8, self.bounds.size.height - y - height, MESSAGE_FRAME.size.width - 16, height); 

    //Core text method 
    CTFontRef fontRef = CTFontCreateWithName((CFStringRef)@"Crimson", 15.0f, NULL); 

    NSDictionary *attDictionary = [NSDictionary dictionaryWithObjectsAndKeys: 
            (__bridge_transfer id)fontRef, (NSString *)kCTFontAttributeName, 
            (id)[[UIColor blueColor] CGColor], (NSString *)kCTForegroundColorAttributeName, 
            nil]; 

    NSAttributedString *attString = [[NSAttributedString alloc] initWithString:self.entry.message attributes:attDictionary]; 

    //Flip the coordinate system 
    CGContextSetTextMatrix(context, CGAffineTransformIdentity); 
    CGContextTranslateCTM(context, 0, self.bounds.size.height); 
    CGContextScaleCTM(context, 1.0, -1.0); 



    CGMutablePathRef path = CGPathCreateMutable(); 
    CGPathAddRect(path, NULL, rect2); 

    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge_retained CFAttributedStringRef)attString); 
    CTFrameRef theFrame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, [attString length]), path, NULL); 
    CFRelease(framesetter); 
    CFRelease(path); 

    CTFrameDraw(theFrame, context); 
    CFRelease(theFrame); 

Die Schriftart ist die gleiche. Ich verstehe nicht, warum man anders dargestellt wird.

Answer 1

Es ist, weil NSLayoutManager einige ungewöhnliche Heuristiken verwendet, um bestimmte Schriftarten zu bewältigen.

Weitere Informationen finden Sie unter How does line spacing work in Core Text? (and why is it different from NSLayoutManager?).