UILabel動態計算寬高度

        動態計算寬時， CGSize size  = CGSizeMake(1000000000000.0,height)的高度固定寬寫無窮大；同理動態計算高度CGSize size  = CGSizeMake(width, 1000000000000.0);寬度固定高度寫無窮大。

//動態計算高度

-(CGFloat)heightWithWidth:(CGFloat)width font:(CGFloat)font str:(NSString *)string{

    UIFont * fonts = [UIFontsystemFontOfSize:font];

    CGSize size  =CGSizeMake(width, 1000000000000.0);

    NSDictionary * dict  = [NSDictionarydictionaryWithObjectsAndKeys:fonts,NSFontAttributeName ,nil];

    size = [string boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOriginattributes:dict context:nil].size;

    return size.height;

}

//動態計算寬度

-(CGFloat)heightWithWidth:(CGFloat)height font:(CGFloat)font str:(NSString *)string{

    UIFont * fonts = [UIFont systemFontOfSize:font];

    CGSize size  = CGSizeMake(1000000000000.0,height);

    NSDictionary * dict  = [NSDictionarydictionaryWithObjectsAndKeys:fonts,NSFontAttributeName ,nil];

    size = [string boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:dict context:nil].size;

    return size.width;

}