政务服务平台,福州短视频seo程序,四川网站推广优化,哈尔滨网站建设流程一、概述 1.CoreText是苹果创建的一个用于文字排版的框架#xff0c;可以实现文字排版、图文混排等复杂的界面效果。从iOS3.2启用。2.一个开源工具类-OHAttributedLabel#xff0c;就是使用CoreText框架实现的#xff0c;能够实现一个Label中有不同的文字大小、文字颜色、字…一、概述 1.CoreText是苹果创建的一个用于文字排版的框架可以实现文字排版、图文混排等复杂的界面效果。从iOS3.2启用。2.一个开源工具类-OHAttributedLabel就是使用CoreText框架实现的能够实现一个Label中有不同的文字大小、文字颜色、字体以及链接等。 二、一般使用步骤1.创建NSMutableAttributedStringNSMutableAttributedString *attributeString [[NSMutableAttributedString alloc] initWithString:contentString];2.设置文字颜色 [attributeString addAttribute:(id)kCTForegroundColorAttributeNamevalue:(id)[UIColor darkGrayColor].CGColor range:NSMakeRange(0, tempArticle.desc.length)];2.设置字体以及大小 CTFontRef font CTFontCreateWithName(CFSTR(Bodoni 72), contentFontSize, NULL);[attributeString addAttribute:(id)kCTFontAttributeName value:(id)font range:NSMakeRange(0, [attributeString length])];CFRelease(font);4.初始化段落首行缩进样式CGFloat headIndent contentFontSize * 2;CTParagraphStyleSetting headIndentStyle;headIndentStyle.spec kCTParagraphStyleSpecifierFirstLineHeadIndent;headIndentStyle.valueSize sizeof(headIndent);headIndentStyle.value headIndent;5.初始化文字对齐方式 CTTextAlignment alignment kCTJustifiedTextAlignment;CTParagraphStyleSetting alignmentStyle;alignmentStyle.spec kCTParagraphStyleSpecifierAlignment;alignmentStyle.valueSize sizeof(alignment);alignmentStyle.value alignment;6.初始化行间距CGFloat lineSpace 12.0f;CTParagraphStyleSetting lineSpaceStyle;lineSpaceStyle.spec kCTParagraphStyleSpecifierLineSpacing;lineSpaceStyle.valueSize sizeof(lineSpace);lineSpaceStyle.value lineSpace;7.初始化段间距CGFloat paragraphSpace 18;CTParagraphStyleSetting paragraphSpaceStyle;paragraphSpaceStyle.spec kCTParagraphStyleSpecifierParagraphSpacing;paragraphSpaceStyle.valueSize sizeof(paragraphSpace);paragraphSpaceStyle.value paragraphSpace;8.将段落属性设置到NSMutableAttributedStringCTParagraphStyleSetting settings[4] {headIndentStyle,alignmentStyle,lineSpaceStyle,paragraphSpaceStyle};CTParagraphStyleRef paragraphStyle CTParagraphStyleCreate((const CTParagraphStyleSetting*)settings,4);[attributeString addAttribute:(id)kCTParagraphStyleAttributeName value:(id)paragraphStyle range:NSMakeRange(0, [attributeString length])];CFRelease(paragraphStyle);9.创建CTFramesetterRef CTFramesetterRef frameSetter CTFramesetterCreateWithAttributedString((CFAttributedStringRef)attributeString);10.绘制之前翻转绘图坐标系CGContextRef context UIGraphicsGetCurrentContext();CGContextSetTextMatrix(context, CGAffineTransformIdentity);CGContextTranslateCTM(context, 0, self.bounds.size.height);CGContextScaleCTM(context, 1.0, -1.0);11.按照区域进行绘制 CFIndex startIndex 0; NSInteger pathCount 0;while (YES) {//构建绘图区域CGMutablePathRef columnPath CGPathCreateMutable();CGPathAddRect(columnPath, NULL,CGRectMake(20 (pathCount%columnNum) * ((768-(columnNum1)*20)/columnNum 20), 50, (768-(columnNum1)*20)/columnNum, 904));//构建内容窗体CTFrameRef frame CTFramesetterCreateFrame(frameSetter, CFRangeMake(startIndex,0), columnPath, NULL);//绘制内容窗体CTFrameDraw(frame, context);//计算当前显示结束位置的字符索引CFRange currRange CTFrameGetVisibleStringRange(frame);startIndex startIndex currRange.length;//释放CGPathRelease(columnPath);CFRelease(frame);//计数增加 pathCount;//结束if (startIndex [attributeString length]) {break;}}12.按照行进行绘制CFIndex start 0;while (YES) {//判断是否绘制完毕if (start attributeString.length) {break;}//根据内容、开始索引位置和绘制区域的宽度返回推荐的换行位置索引CFIndex count CTTypesetterSuggestLineBreak(frameSetter, start, pageWidth);//创建一个新行CTLineRef line CTTypesetterCreateLine(frameSetter, CFRangeMake(start, count));//获取新行的排版属性 CGFloat ascent;CGFloat descent;CGFloat leading;CTLineGetTypographicBounds(line, ascent, descent, leading);//计算新行的Y值 imageY imageY - lineSpace - ascent - descent - leading;//绘制行 CGContextSetTextPosition(currContext, 0.0f, imageY);CTLineDraw(line, currContext);//释放行对象 CFRelease(line);//更改当前绘制的位置索引 start count;}
