iOS中求出label中文字的行数和每一行的内容

今天遇到一个需求，需要计算label中文字的行数。想了好久也没想到好的解决方法，就在网上找了下。结果发现一篇文章是讲这个的。这部分代码不但能够求出一个label中文字行数，更厉害的是能够求出每一行的内容是什么；

- (NSArray *)getLinesArrayOfStringInLabel:(UILabel *)label{
    NSString *text = [label text];
    UIFont *font = [label font];
    CGRect rect = [label frame];

    CTFontRef myFont = CTFontCreateWithName(( CFStringRef)([font fontName]), [font pointSize], NULL);
    NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc] initWithString:text];
    [attStr addAttribute:(NSString *)kCTFontAttributeName value:(__bridge  id)myFont range:NSMakeRange(0, attStr.length)];
    CFRelease(myFont);
    CTFramesetterRef frameSetter = CTFramesetterCreateWithAttributedString(( CFAttributedStringRef)attStr);
    CGMutablePathRef path = CGPathCreateMutable();
    CGPathAddRect(path, NULL, CGRectMake(0,0,rect.size.width,100000));
    CTFrameRef frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, 0), path, NULL);
    NSArray *lines = ( NSArray *)CTFrameGetLines(frame);
    NSMutableArray *linesArray = [[NSMutableArray alloc]init];
    for (id line in lines) {
        CTLineRef lineRef = (__bridge  CTLineRef )line;
        CFRange lineRange = CTLineGetStringRange(lineRef);
        NSRange range = NSMakeRange(lineRange.location, lineRange.length);
        NSString *lineString = [text substringWithRange:range];
        CFAttributedStringSetAttribute((CFMutableAttributedStringRef)attStr, lineRange, kCTKernAttributeName, (CFTypeRef)([NSNumber numberWithFloat:0.0]));
        CFAttributedStringSetAttribute((CFMutableAttributedStringRef)attStr, lineRange, kCTKernAttributeName, (CFTypeRef)([NSNumber numberWithInt:0.0]));
        //NSLog(@"''''''''''''''''''%@",lineString);
        [linesArray addObject:lineString];
    }

    CGPathRelease(path);
    CFRelease( frame );
    CFRelease(frameSetter);
    return (NSArray *)linesArray;
}

作者：黑黑的小土豆
链接：http://www.jianshu.com/p/33b93b39311a
來源：简书
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