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