CoreText 简单 使用

 - (void)drawRect:(CGRect)rect
 {
     NSString *longText = @"CoreText"; /* ... */
     NSRange rang =[self.hightString rangeOfString:longText];
     longText = @"CoreText";
      NSMutableAttributedString *string = [[NSMutableAttributedString alloc]
                                          initWithString:longText];

     if (rang.location == NSNotFound)
     {

     }

     // make a few words bold
     CTFontRef helvetica = CTFontCreateWithName(CFSTR("Helvetica"), 14.0, NULL);
     CTFontRef helveticaBold = CTFontCreateWithName(CFSTR("Helvetica-Bold"), 14.0, NULL);

     [string addAttribute:(id)kCTFontAttributeName
                    value:(__bridge id)helvetica
                    range:NSMakeRange(, [string length])];

     [string addAttribute:(id)kCTForegroundColorAttributeName
                    value:(id)[UIColor redColor].CGColor
                    range:NSMakeRange(, )];

     // layout master
     CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(
                                                                            (CFAttributedStringRef)string);

     // left column form
     CGMutablePathRef leftColumnPath = CGPathCreateMutable();
     CGPathAddRect(leftColumnPath, NULL,
                   CGRectMake(, ,
                              self.bounds.size.width/2.0,
                              self.bounds.size.height));

     // left column frame
     CTFrameRef leftFrame = CTFramesetterCreateFrame(framesetter,
                                                     CFRangeMake(, ),
                                                     leftColumnPath, NULL);

     // right column form
     CGMutablePathRef rightColumnPath = CGPathCreateMutable();
     CGPathAddRect(rightColumnPath, NULL,
                   CGRectMake(self.bounds.size.width/2.0, ,
                              self.bounds.size.width/2.0,
                              self.bounds.size.height));

     NSInteger rightColumStart = CTFrameGetVisibleStringRange(leftFrame).length;

     // right column frame
     CTFrameRef rightFrame = CTFramesetterCreateFrame(framesetter,
                                                      CFRangeMake(rightColumStart, ),
                                                      rightColumnPath,
                                                      NULL);

     // flip the coordinate system
     CGContextRef context = UIGraphicsGetCurrentContext();
     CGContextSetTextMatrix(context, CGAffineTransformIdentity);
     CGContextTranslateCTM(context, , self.bounds.size.height);
     CGContextScaleCTM(context, 1.0, -1.0);

     // draw
     CTFrameDraw(leftFrame, context);
     CTFrameDraw(rightFrame, context);

     // cleanup
     CFRelease(leftFrame);
     CGPathRelease(leftColumnPath);
     CFRelease(rightFrame);
     CGPathRelease(rightColumnPath);
     CFRelease(framesetter);
     CFRelease(helvetica);
     CFRelease(helveticaBold);
    // [string release];

 }

CoreText