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； 代码如下。

#import <CoreText/CoreText.h>

- (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;

}