CoreText学习笔记（1）

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

CGContextScaleCTM(context, 1.0, -1.0);

在iOS中使用CoreText需要转换

绘制一段文字

1、获取需要绘制的文字

CFStringRef textString = (__bridge CFStringRef)@"ABCDEFGHIJKLMNOPQRSTUVWXYZ";

2、创建属性字符串

CFMutableAttributedStringRef attrString = CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);

3、将绘制位子复制到属性字符串中

CFAttributedStringReplaceString (attrString, CFRangeMake(0, 0),textString);

4、设置属性，例如颜色

CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();

CGFloat components[] = { 1.0, 0.0, 0.0, 0.8 };

CGColorRef red = CGColorCreate(rgbColorSpace, components);

CGColorSpaceRelease(rgbColorSpace);

CFAttributedStringSetAttribute(attrString, CFRangeMake(0, 14),kCTForegroundColorAttributeName, red);

5、根据属性字符串创建FrameSetter

CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrString);

CFRelease(attrString);

6、创建绘制路径

CGMutablePathRef path = CGPathCreateMutable();

CGRect bounds = CGRectMake(10.0, 10.0, 190.0, 200.0);

CGPathAddRect(path, NULL, bounds );

7、根据路径和frameSetter创建Frame

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

8、在当前上下文中绘制Frame

CTFrameDraw(frame, context);

CFRelease(frame);

CFRelease(path);

CFRelease(framesetter);