郑州网站的优化/晋江友情链接是什么意思

本文参考过：http://www.dev3g.com/?p=27

core text真的是一个不错的东东，用其实现富文本比较多见。

core text要配合着NSMutableAttributedString来用，基本可以这样理解，文本属性全部在NSMutableAttributedString上设。

比如

CTFontRef helvetica = CTFontCreateWithName(CFSTR(”Helvetica”), fontSize, NULL);

[_attributedText addAttribute:(id)kCTFontAttributeName value:(id)helvetica range:NSMakeRange(0, [string length])];

以及

//创建文本对齐方式

CTTextAlignment alignment = kCTLeftTextAlignment;//左对齐kCTRightTextAlignment为右对齐

CTParagraphStyleSetting alignmentStyle;

alignmentStyle.spec=kCTParagraphStyleSpecifierAlignment;//指定为对齐属性

alignmentStyle.valueSize=sizeof(alignment);

alignmentStyle.value=&alignment;

//创建文本行间距

CGFloat lineSpace=20;//间距数据

CTParagraphStyleSetting lineSpaceStyle;

lineSpaceStyle.spec=kCTParagraphStyleSpecifierMinimumLineHeight;//指定最小行高

lineSpaceStyle.valueSize=sizeof(lineSpace);

lineSpaceStyle.value=&lineSpace;

CTParagraphStyleSetting paraStyles[2] = {

{.spec = kCTParagraphStyleSpecifierAlignment, .valueSize = sizeof(CTTextAlignment), .value = (const void*)&alignment},

{.spec = kCTParagraphStyleSpecifierLineBreakMode, .valueSize = sizeof(CTLineBreakMode), .value = (const void*)&lineBreakMode},

};

CTLineBreakMode lineBreakMode = kCTLineBreakByCharWrapping;

CTParagraphStyleSetting settings[]={

alignmentStyle,lineSpaceStyle,

{.spec = kCTParagraphStyleSpecifierLineBreakMode, .valueSize =sizeof(CTLineBreakMode), .value = (const void*)&lineBreakMode},

};//创建出一个样式数组

CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(settings, sizeof(settings));

[_attributedText addAttribute:(id)kCTParagraphStyleAttributeName value:(id)paragraphStyle range:NSMakeRange(0, [string length])]; //将刚刚创建的样式应用到attributedtext上

CFRelease(paragraphStyle);

下面是开始画了，需要注意的1点就是画出来坐标是反的，要转一下

CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(

(CFAttributedStringRef)_attributedText);

CGMutablePathRef leftColumnPath = CGPathCreateMutable();

CGPathAddRect(leftColumnPath, NULL,

CGRectMake(0, 0,

self.bounds.size.width,

self.bounds.size.height));

CTFrameRef leftFrame = CTFramesetterCreateFrame(framesetter,

CFRangeMake(0, 0),

leftColumnPath, NULL);

CGContextRef context = UIGraphicsGetCurrentContext();

CGContextSetTextMatrix(context, CGAffineTransformIdentity);

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

CGContextScaleCTM(context, 1.0, -1.0);

CTFrameDraw(leftFrame, context);//此处也可以单行来画，CTLineDraw

CGPathRelease(leftColumnPath);

CFRelease(framesetter);

CFRelease(helvetica);

[_attributedText release];

UIGraphicsPushContext(context);