计算UITextView的滑动高度

- (CGFloat)getHeightByTextView:(UITextView *)myTextView withContent:(NSString *)content withFontSize:(CGFloat)size withTextColor:(UIColor *)color
{
    CGFloat newSizeH = 0.;
    //UITextView的实际高度
    if ([[[UIDevice currentDevice] systemVersion] floatValue]>=7.0)
    {
        //7.0以后需要自己计算高度
        float fPadding = 16.0; //8.0px x 2
        
//        CGSize constraint = CGSizeMake(myTextView.contentSize.width - fPadding,CGFLOAT_MAX);
//        CGSize size = [self.textView.text sizeWithFont:myTextView.font constrainedToSize:constraint lineBreakMode:NSLineBreakByWordWrapping];
//        newSizeH = size.height;
        
        CGSize constraint = CGSizeMake(myTextView.contentSize.width - fPadding, CGFLOAT_MAX);
        NSDictionary *attrsDictionary = [NSDictionary dictionaryWithObjectsAndKeys:[UIFont fontWithName:@"Helvetica Neue" size:size],NSFontAttributeName,color,NSForegroundColorAttributeName, nil];
        NSStringDrawingOptions options = NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading;
        CGRect rect = [myTextView.text boundingRectWithSize:constraint options:options  attributes:attrsDictionary context:nil];
        newSizeH = rect.size.height;
    }
    else
    {
        newSizeH = myTextView.contentSize.height + 10;
    }
    return newSizeH;
}