为数据前面加上货币符号

/// <summary>
/// 商品价格格式
/// </summary>
/// <param name="price"></param>
/// <param name="n"></param>
/// <returns></returns>
public static string GetPrice(this decimal price, int? n = 0)
{
//if (n!=0)
//{

//}
return string.Format("{0:c" + n + "}", price);
}
public static string GetPriceForInt(this int price, int? n = 0)
{
//if (n!=0)
//{

//}
return string.Format("{0:c" + n + "}", price);
}