iOS中求出label中文字的行数和每一行的内容

ios swift 获取UIlabel的文字行数，每一行的内容。 记录 ----> 荔枝

下面代码不但能够求出一个label中文字行数，厉害的是能够求出每一行的内容是什么； 代码如下。

OC

- (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;
}

swift

 extension UILabel {
    /// 字符串分行后获取每行的内容
    /// 通过富文本分行，然后通过CTframe获取每一行的内容
    func linesOfString() -> [String] {
        var strings: [String] = []
        guard let text = text,
              let font = font else { return [] }
        let attstr = NSMutableAttributedString(string: text, attributes: [NSAttributedString.Key.font: font])
        
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineBreakMode = .byWordWrapping
        attstr.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSMakeRange(0, text.count))
        
        let frameSetter = CTFramesetterCreateWithAttributedString(attstr as CFAttributedString)
        
        let path = CGMutablePath()
        path.addRect(CGRect(x: 0, y: 0, width: frame.size.width, height: 100))
        
        let frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, 0), path, nil)
        
        if let lines = CTFrameGetLines(frame) as? [CTLine] {
            lines.forEach({
                let linerange = CTLineGetStringRange($0)
                let range = NSMakeRange(linerange.location, linerange.length)
                let string = (text as NSString).substring(with: range)
                strings.append(string)
            })
        }
        return strings
    }
}