如何让异常在C#中定义自己的消息?

我想定义一个自定义异常,它有两个特殊属性:Field和FieldValue,我想从异常构造函数中的这两个值生成消息。不幸的是,消息是只读的。

    public class FieldFormatException: FormatException
    {
        private Fields _field;
        private string _fieldValue;
        public Fields Field{ get{ return _field; } }
        public string FieldValue { get { return _value; } }
        public FieldFormatException() : base() { }
        private FieldFormatException(string message) { }
        public FieldFormatException(string message, Fields field, string value): 
            base(message)
        {
            _fieldValue = value;
            _field = field;               
        }
        public FieldFormatException(string message, Exception inner, Fields field, string value): 
            base(message, inner)
        {
            _fieldValue = value;
            _field = field;
        }
        protected FieldFormatException(System.Runtime.Serialization.SerializationInfo info,
              System.Runtime.Serialization.StreamingContext context): base(info, context){}
    }

如何将消息作为参数从构造函数中删除,然后根据Field和FieldValue的值设置消息?