CoreText实现图文混排

1. 第一步，引入CoreText.framework框架。
2. //CoreText  跨平台
3. 以lable为例
4.  
5. NSDictionary *attributes = @{
6.          NSFontAttributeName: [UIFont systemFontOfSize:14],
7.          NSForegroundColorAttributeName: [UIColor blackColor]，
8.     };
9. NSMutableAttributedString *attrtext = [[NSMutableAttributedString alloc] initWithString:text attributes:attributes];

10.//设置文本属性

1. [attrtext addAttribute:NSUnderlineStyleAttributeName
2. value:@2
3. range:NSMakeRange(0, 3)];

15.//Foundation  ---> CoreFoundation

1. NSString *s = @"tt";
2. CFStringRef s2 = (__bridge CFStringRef)s;

18.//1.通过NSMutableAttributedString 文本属性对象  构造--->CTFramesetterRef

1. CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)attrtext);

20.//2.构造CGPath

1. CGMutablePathRef path = CGPathCreateMutable();

22.//    CGRectInset(<#CGRect rect#>, <#CGFloat dx#>, <#CGFloat dy#>)

1. CGPathAddRect(path, NULL, self.bounds);

24.//3.通过CTFramesetterRef和CGPath 构造出一个CTFrameRef

1. CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), path, NULL);

26.//4.取得绘制的上下文

1. CGContextRef ctx = UIGraphicsGetCurrentContext();
2. //坐标系统向下平移当前视图的高度
3. CGContextTranslateCTM(ctx, 0, CGRectGetHeight(self.bounds));
4. //缩放倍数为-1，使用坐标指向反方向
5. CGContextScaleCTM(ctx, 1, -1.0);

32.//5.绘制frame

1. CTFrameDraw(frame, ctx);
2. //取得frmae中所有的行
3. CFArrayRef lines = CTFrameGetLines(frame);
5. //绘制一行

38.//    CTLineDraw(<#CTLineRef line#>, <#CGContextRef context#>)

2. CTLineRef line;
3. CFArrayRef runs = CTLineGetGlyphRuns(line);

42.//    CTRunDraw(<#CTRunRef run#>, <#CGContextRef context#>, <#CFRange range#>)

45.常用开源框架

46.FTCoreText

47.DTCoreText