swift 富文本 获取文本size

var attributeString = NSMutableAttributedString(string:"welcome to hangge.com")

//从文本0开始6个字符字体HelveticaNeue-Bold,16号

attributeString.addAttribute(NSFontAttributeName, value: UIFont(name: "HelveticaNeue-Bold", size: 16)!,

    range: NSMakeRange(0,6))

//设置字体颜色

attributeString.addAttribute(NSForegroundColorAttributeName, value: UIColor.blueColor(),

    range: NSMakeRange(0, 3))

//设置文字背景颜色

attributeString.addAttribute(NSBackgroundColorAttributeName, value: UIColor.greenColor(),

    range: NSMakeRange(3,3))

label.attributedText = attributeString

 

//＝＝＝＝＝＝＝获取文本size＝＝＝＝＝＝＝＝＝

+ (CGSize)sizeWithString:(NSString *)str font:(UIFont *)font maxSize:(CGSize)maxSize

{

    NSDictionary *dict = @{NSFontAttributeName : font};

    CGSize size =  [str boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin attributes:dict context:nil].size;

    return size;

}