从iOS 10.3开始：UIButton忽略NSAttributedString中的负段lineSpacing

Question

I have a UIButton which is really just 2 words, wrapped to 2 lines (I set the lines value to "2" in code later). I have been tightening up the default lineSpacing by putting in a negative value for the paragraph lineSpacing (as simplified & shown below).

As of iOS 10.3, it appears the negative value is now being ignored. While I can increase the lineSpacing with a positive value, I can not tighten up the 2 lines anymore.

Does anyone else know how to tighten this up in a UIButton? (I'm about ready to change that control up... but thought I'd post the question).

Much thanks all.

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = -15.0f;
paragraphStyle.alignment = NSTextAlignmentLeft;

NSDictionary * attributes = [NSDictionary dictionaryWithObjectsAndKeys:
                             [UIColor whiteColor], NSStrokeColorAttributeName,
                             [UIColor greenColor], NSForegroundColorAttributeName,
                             @(-2.0), NSStrokeWidthAttributeName,
                             paragraphStyle, NSParagraphStyleAttributeName,
                             nil];
NSMutableAttributedString *buttonTitle = [[NSMutableAttributedString alloc] initWithString:str attributes:attributes];

self.theButton.titleLabel.numberOfLines = 2;
[self.theButton setAttributedTitle:buttonTitle forState:UIControlStateNormal];

edit: Looks like this is also an issue with UILabel also.

Answer 1

i can change the line space using the code in iOS 10.2

NSMutableParagraphStyle *paraStyle = [NSMutableParagraphStyle defaultParagraphStyle].mutableCopy;
paraStyle.alignment = NSTextAlignmentCenter;
paraStyle.lineBreakMode = NSLineBreakByCharWrapping;
paraStyle.paragraphSpacing = -8;

[self setAttributedTitle:[[NSAttributedString alloc] initWithString:[NSString stringWithFormat:@"test button\n normal", titleString] attributes:@{NSParagraphStyleAttributeName:paraStyle}] forState:UIControlStateNormal];
[self setAttributedTitle:[[NSAttributedString alloc] initWithString:[NSString stringWithFormat:@"test button\n selected", titleString] attributes:@{NSParagraphStyleAttributeName:paraStyle}] forState:UIControlStateSelected];

i guess maybe you can change the paragraphSpacing, it works~