• IOS利用Core Text对文字进行排版


    原贴地址:http://hi.baidu.com/jwq359699768/blog/item/5df305c893413d0a7e3e6f7b.html

    core text 这个包默认是没有的,要自己手动添加进来。

    在IOS中利用core text对文本进行排版的几个关键点如下:

         字间距:kCTKernAttributeName

         行间距:kCTParagraphStyleSpecifierLineSpacingAdjustment 或 kCTParagraphStyleSpecifierLineSpacing(不推荐使用)

        段间距:kCTParagraphStyleSpecifierParagraphSpacing

       文本对齐方式:kCTParagraphStyleSpecifierAlignment;

    还有一点就是core text显示出来的字是颠倒的,使用时要翻转下:

       CGContextRef context = UIGraphicsGetCurrentContext();

       CGContextSetTextMatrix(context,CGAffineTransformIdentity);

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

       CGContextScaleCTM(context,1.0,-1.0);

    最后一点要注意的是Mac下的回车和Windows的是不一样的,Windows下的回车是由 组成的而Mac下只有一个 ,所以如果没有去掉的话在每一段的最后都会多出一个空行来,去掉的方法如下:

    NSString *myString = [labelString stringByReplacingOccurrencesOfString:" " withString:" "];

    具体的代码实现如下:

    #import<Foundation/Foundation.h>

    #import<UIKit/UIKit.h>

    @interface TextLayoutLabel : UILabel

    {

    @private

        CGFloat characterSpacing_;       //字间距

    @private

      long linesSpacing_;   //行间距

    }

    @property(nonatomic,assign) CGFloat characterSpacing;

    @propery(nonatomic,assign)long linesSpacing;

    @end

    #import "TextLayoutLabel.h"

    #import<CoreText/CoreText.h>

    @implementation TextLayoutLabel

    @synthesize characterSpacing = characterSpacing_;

    @synthesize linesSpacing = linesSpacing_;

    -(id) initWithFrame:(CGRect)frame

     {//初始化字间距、行间距

      if(self =[super initWithFrame:frame])

    {

      self.characterSpacing = 2.0f;

      self.linesSpacing = 5.0f;

    }

    return self;

    }

    -(void)setCharacterSpacing:(CGFloat)characterSpacing //外部调用设置字间距

    {

    characterSpacing_ = characterSpacing;

    [self setNeedsDisplay];

    }

    -(void)setLinesSpacing:(long)linesSpacing  //外部调用设置行间距

    {

      linesSpacing_ = linesSpacing;

      [self setNeedsDisplay];

    }

    -(void) drawTextInRect:(CGRect)requestedRect

    {

    //去掉空行

    NSString *labelString = self.text;

    NSString *myString = [labelString stringByReplacingOccurrencesOfString:@" " withString:" "];

    //创建AttributeString

    NSMutableAttributedString *string =[[NSMutableAttributedString alloc]initWithString:self.text];

    //设置字体及大小

    CTFontRef helveticaBold = CTFontCreateWithName((CFStringRef)self.font.fontName,self.font.pointSize,NULL);

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

    //设置字间距

    if(self.characterSpacing)

    {

      long number = self.characterSpacing;

      CFNumberRef num = CFNumberCreate(kCFAllocatorDefault,kCFNumberSInt8Type,&number);

      [string addAttribute:(id)kCTkernAttributeName value:(id)num rang:NSMakeRange(0,[string length])];

      CFRelease(num);

    }

    //设置字体颜色

    [string addAttribute:(id)kCTForegroundColorAttributeName value:(id)(self.textColor.CGColor) range:NSMakeRange(0,[string length])];

    //创建文本对齐方式

    CTTextAlignment alignment = kCTLeftTextAlignment;

    if(self.textAlignment == UITextAlignmentCenter)

    {

       alignment = kCTCenterTextAlignment;

    }

    if(self.textAlignment == UITextAlignmentRight)

    {

      alignment = kCTRightTextAlignment;

    }

    CTParagraphStyleSetting alignmentStyle;

    alignmentStyle.spec = kCTParagraphStyleSpecifierAlignment;

    alignmentStyle.valueSize = sizeof(alignment);

    alignmentStyle.value = &alignment;

    //设置文本行间距

    CGFloat lineSpace = self.linesSpacing;

    CTParagraphStyleSetting lineSpaceStyle;

     lineSpaceStyle.spec = kCTparagraphStyleSpecifierLineSpacingAdjustment;

     lineSpaceStyle.valueSize = sizeof(lineSpace);

     lineSpaceStyle.value =&lineSpace;

    //设置文本段间距

    CGFloat paragraphSpacing = 5.0;

    CTparagraphStyleSetting paragraphSpaceStyle;

     paragraphSpaceStyle.spec = kCTparagraphStyleSpecifierParagraphSpacing;

     paragraphSpaceStyle.valueSize = sizeof(CGFloat);

     paragraphSpaceStyle.value = &paragraphSpacing;

    //创建设置数组

    CTParagraphStyleSetting settings[ ] ={alignmentStyle,lineSpaceStyle,paragraphSpaceStyle};

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

    //给文本添加设置

    [string addAttribute:(id)kCTParagraphStyleAttributeName value:(id)style range:NSMakeRange(0 , [string length])];

    //排版

    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)string);

    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);

    //翻转坐标系统(文本原来是倒的要翻转下)

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetTextMatrix(context , CGAffineTransformIdentity);

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

    CGContextScaleCTM(context, 1.0 ,-1.0);

    //画出文本

    CTFrameDraw(leftFrame,context);

    //释放

    CGPathRelease(leftColumnPath);

    CFReleale(framesetter);

    CFRelease(helveticaBold);

    [string release];

    UIGraphicsPushContext(context);

    }

    @end

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  • 原文地址:https://www.cnblogs.com/endtel/p/4860664.html
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