coreText
对于画文本可以很多做过iphone开发的人员都曾为bojective－c语言的设计而苦恼。前几天我也因为文本的排版很纠结。看了很多上架了的软件一样有此类问题，这虽不伤产品功能，但很伤大雅。
//创建要输出的字符串f
NSString *longText = @"自己添加文本";
//创建AttributeStringfdsa
NSMutableAttributedString *string = [[NSMutableAttributedString alloc]
initWithString:longText];
//创建字体以及字体大小
CTFontRef helvetica = CTFontCreateWithName(CFSTR("Helvetica"), 14.0, NULL);
CTFontRef helveticaBold = CTFontCreateWithName(CFSTR("Helvetica-Bold"), 14.0,NULL);
//添加字体目标字符串从下标0开始到字符串结尾
[string addAttribute:(id)kCTFontAttributeName
value:(id)helvetica
range:NSMakeRange(0, [string length])];
//添加字体目标字符串从下标0开始，截止到4个单位的长度
[string addAttribute:(id)kCTFontAttributeName
value:(id)helveticaBold
range:NSMakeRange(0, 4)];
//添加字体目标字符串从下标6开始，截止到5个单位长度
[string addAttribute:(id)kCTFontAttributeName
value:(id)helveticaBold
range:NSMakeRange(6, 5)];
//添加字体目标字符串从下标109开始，截止到9个单位长度
[string addAttribute:(id)kCTFontAttributeName
value:(id)helveticaBold
range:NSMakeRange(109, 9)];
//添加字体目标字符串从下标223开始，截止到6个单位长度
[string addAttribute:(id)kCTFontAttributeName
value:(id)helveticaBold
range:NSMakeRange(223, 6)];
//添加颜色，目标字符串从下标0开始，截止到4个单位长度
[string addAttribute:(id)kCTForegroundColorAttributeName
value:(id)[UIColor blueColor].CGColor
range:NSMakeRange(0, 4)];
//添加过程同上
[string addAttribute:(id)kCTForegroundColorAttributeName
value:(id)[UIColor redColor].CGColor
range:NSMakeRange(18, 3)];
[string addAttribute:(id)kCTForegroundColorAttributeName
value:(id)[UIColor greenColor].CGColor
range:NSMakeRange(657, 6)];
[string addAttribute:(id)kCTForegroundColorAttributeName
value:(id)[UIColor blueColor].CGColor
range:NSMakeRange(153, 6)];
//创建文本对齐方式
CTTextAlignment alignment = kCTJustifiedTextAlignment;//这种对齐方式会自动调整，使左右始终对齐
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=10.0f;//间距数据
CTParagraphStyleSetting lineSpaceStyle;
lineSpaceStyle.spec=kCTParagraphStyleSpecifierLineSpacing;//指定为行间距属性
lineSpaceStyle.valueSize=sizeof(lineSpace);
lineSpaceStyle.value=&lineSpace;
//创建样式数组
CTParagraphStyleSetting settings[]={
alignmentStyle,lineSpaceStyle
};
//设置样式
CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(settings,sizeof(settings));
//给字符串添加样式attribute
[string addAttribute:(id)kCTParagraphStyleAttributeName
value:(id)paragraphStyle
range:NSMakeRange(0, [string length])];
// layout master
framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)string);
//计算文本绘制size
CGSize tmpSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter,CFRangeMake(0,0), NULL, CGSizeMake(385, 400 * 10), NULL);
//创建textBoxSize以设置view的frame
CGSize textBoxSize = CGSizeMake((int)tmpSize.width + 1, (int)tmpSize.height +1);
NSLog(@"textBoxSize == %f,%f,%f",textBoxSize.width,textBoxSize.height,textBoxSize.width / textBoxSize.height);
self.frame = CGRectMake(6, 0, textBoxSize.width , textBoxSize.height);
[string release];
//- (void)drawRect:(CGRect)rect;代码
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);
NSLog(@"textBoxSize == %f,%f,%f",self.frame.size.width,self.frame.size.height);
// flip the coordinate system
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CGContextTranslateCTM(context, 0, self.bounds.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
// draw
CTFrameDraw(leftFrame, context);
// cleanup
CGPathRelease(leftColumnPath);
CFRelease(framesetter);
//CFRelease(helvetica);
// CFRelease(helveticaBold);
UIGraphicsPushContext(context);
然后可以将这个view添加到scrollview里面就ok了，跟textview一样有滑动效果，但样式漂亮多了