NSString  *text = @"This\nis\nsome\nmulti-line\nsample\ntext.";

        UIFont    *uiFont = [UIFont fontWithName:@"Helvetica" size:17.0];

        CTFontRef ctFont = CTFontCreateWithName((CFStringRef) uiFont.fontName, uiFont.pointSize, NULL);

//

//        //  When you create an attributed string the default paragraph style has a leading

//        //  of 0.0. Create a paragraph style that will set the line adjustment equal to

//        //  the leading value of the font.

//        CGFloat leading = uiFont.lineHeight - uiFont.ascender + uiFont.descender;

//        CTParagraphStyleSetting paragraphSettings[1] = { kCTParagraphStyleSpecifierLineSpacingAdjustment, sizeof (CGFloat), &leading };

//

//        CTParagraphStyleRef  paragraphStyle = CTParagraphStyleCreate(paragraphSettings, 1);

        // direction

        CTWritingDirection direction = kCTWritingDirectionLeftToRight;

        // leading

        CGFloat firstLineIndent = 0.0;

        CGFloat headIndent = 0.0;

        CGFloat tailIndent = 0.0;

        CGFloat lineHeightMultiple = 1.0;

        CGFloat maxLineHeight = ;

        CGFloat minLineHeight = ;

        CGFloat paragraphSpacing = 0.0;

        CGFloat paragraphSpacingBefore = 0.0;

        CTTextAlignment textAlignment = kCTTextAlignmentLeft;//(CTTextAlignment)_textAlignment;

        CTLineBreakMode lineBreakMode = kCTLineBreakByWordWrapping;//(CTLineBreakMode)_lineBreakMode;

        CGFloat lineSpacing = ;//_lineSpacing;

        CTParagraphStyleSetting theSettings[] =

        {

            { kCTParagraphStyleSpecifierAlignment, sizeof(CTTextAlignment), &textAlignment },

            { kCTParagraphStyleSpecifierLineBreakMode, sizeof(CTLineBreakMode), &lineBreakMode  },

            { kCTParagraphStyleSpecifierBaseWritingDirection, sizeof(CTWritingDirection), &direction },

            { kCTParagraphStyleSpecifierMinimumLineSpacing, sizeof(CGFloat), &lineSpacing }, // leading

            { kCTParagraphStyleSpecifierMaximumLineSpacing, sizeof(CGFloat), &lineSpacing }, // leading

            { kCTParagraphStyleSpecifierFirstLineHeadIndent, sizeof(CGFloat), &firstLineIndent },

            { kCTParagraphStyleSpecifierHeadIndent, sizeof(CGFloat), &headIndent },

            { kCTParagraphStyleSpecifierTailIndent, sizeof(CGFloat), &tailIndent },

            { kCTParagraphStyleSpecifierLineHeightMultiple, sizeof(CGFloat), &lineHeightMultiple },

            { kCTParagraphStyleSpecifierMaximumLineHeight, sizeof(CGFloat), &maxLineHeight },

            { kCTParagraphStyleSpecifierMinimumLineHeight, sizeof(CGFloat), &minLineHeight },

            { kCTParagraphStyleSpecifierParagraphSpacing, sizeof(CGFloat), &paragraphSpacing },

            { kCTParagraphStyleSpecifierParagraphSpacingBefore, sizeof(CGFloat), &paragraphSpacingBefore }

        };

        CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(theSettings, sizeof(theSettings) / sizeof(CTParagraphStyleSetting));

        CFRange textRange = CFRangeMake(, text.length);

        //  Create an empty mutable string big enough to hold our test

        CFMutableAttributedStringRef string = CFAttributedStringCreateMutable(kCFAllocatorDefault, text.length);

        //  Inject our text into it

        CFAttributedStringReplaceString(string, CFRangeMake(, ), (CFStringRef) text);

        //  Apply our font and line spacing attributes over the span

        CFAttributedStringSetAttribute(string, textRange, kCTFontAttributeName, ctFont);

        CFAttributedStringSetAttribute(string, textRange, kCTParagraphStyleAttributeName, paragraphStyle);

        CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(string);

        CFRange fitRange;

        CGSize frameSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, textRange, NULL, self.view.bounds.size, &fitRange);

　　　　　　CFRelease(paragraphStyle);
　　　　　　CFRelease(ctFont);

        CFRelease(framesetter);

        CFRelease(string);