7.0以前
CGRect mainBounds = [[UIScreen mainScreen] bounds];
UIFont *font = [UIFont systemFontOfSize:15.0f];
CGRect locationBtnFrame = self.locationButton.frame;
CGFloat maxWidth = mainBounds.size.width - locationBtnFrame.origin.x;
CGSize size = CGSizeMake(maxWidth, MAXFLOAT);
CGSize theStringSize = [theText sizeWithFont:font
constrainedToSize:size
lineBreakMode:self.locationButton.lineBreakMode];
self.locationButton.frame = CGRectMake(locationBtnFrame.origin.x,
locationBtnFrame.origin.y,
theStringSize.width, locationBtnFrame.size.height);
7.0以后
NSString *content = button.titleLabel.text;
UIFont *font = button.titleLabel.font;
CGSize size = CGSizeMake(MAXFLOAT, 30.0f);
CGSize buttonSize = [content boundingRectWithSize:size
options:NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading
attributes:@{ NSFontAttributeName:font}
context:nil].size;
