CoreText 简单 使用

 1 - (void)drawRect:(CGRect)rect

 2 {

 3     NSString *longText = @"CoreText"; /* ... */

 4     NSRange rang =[self.hightString rangeOfString:longText];

 5     longText = @"CoreText";

 6      NSMutableAttributedString *string = [[NSMutableAttributedString alloc]

 7                                          initWithString:longText];

 8 

 9     

10     if (rang.location == NSNotFound)

11     {

12        

13     }

14     

15        

16     // make a few words bold

17     CTFontRef helvetica = CTFontCreateWithName(CFSTR("Helvetica"), 14.0, NULL);

18     CTFontRef helveticaBold = CTFontCreateWithName(CFSTR("Helvetica-Bold"), 14.0, NULL);

19     

20     [string addAttribute:(id)kCTFontAttributeName

21                    value:(__bridge id)helvetica

22                    range:NSMakeRange(0, [string length])];

23     

24     

25     [string addAttribute:(id)kCTForegroundColorAttributeName

26                    value:(id)[UIColor redColor].CGColor

27                    range:NSMakeRange(3, 5)];

28     

29     // layout master

30     CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(

31                                                                            (CFAttributedStringRef)string);

32     

33     // left column form

34     CGMutablePathRef leftColumnPath = CGPathCreateMutable();

35     CGPathAddRect(leftColumnPath, NULL,

36                   CGRectMake(0, 0,

37                              self.bounds.size.width/2.0,

38                              self.bounds.size.height));

39     

40     // left column frame

41     CTFrameRef leftFrame = CTFramesetterCreateFrame(framesetter,

42                                                     CFRangeMake(0, 0),

43                                                     leftColumnPath, NULL);

44     

45     // right column form

46     CGMutablePathRef rightColumnPath = CGPathCreateMutable();

47     CGPathAddRect(rightColumnPath, NULL,

48                   CGRectMake(self.bounds.size.width/2.0, 0,

49                              self.bounds.size.width/2.0,

50                              self.bounds.size.height));

51     

52     NSInteger rightColumStart = CTFrameGetVisibleStringRange(leftFrame).length;

53     

54     // right column frame

55     CTFrameRef rightFrame = CTFramesetterCreateFrame(framesetter,

56                                                      CFRangeMake(rightColumStart, 0),

57                                                      rightColumnPath,

58                                                      NULL);

59     

60     // flip the coordinate system

61     CGContextRef context = UIGraphicsGetCurrentContext();

62     CGContextSetTextMatrix(context, CGAffineTransformIdentity);

63     CGContextTranslateCTM(context, 0, self.bounds.size.height);

64     CGContextScaleCTM(context, 1.0, -1.0);

65     

66     // draw

67     CTFrameDraw(leftFrame, context);

68     CTFrameDraw(rightFrame, context);

69     

70     // cleanup

71     CFRelease(leftFrame);

72     CGPathRelease(leftColumnPath);

73     CFRelease(rightFrame);

74     CGPathRelease(rightColumnPath);

75     CFRelease(framesetter);

76     CFRelease(helvetica);

77     CFRelease(helveticaBold);

78    // [string release];

79     

80 }

CoreText