将一个实体的值自动赋值给另一个实体

   
今天需要用到将实体A的字段自动赋值给实体B的字段 

     public static T Convert<U, T>(U _u)
            where U : new()
            where T : new()
        {
            T t_ = new T();  
            PropertyInfo[] tpis = t_.GetType().GetProperties();
            foreach (PropertyInfo tpi in tpis)
            {
                PropertyInfo upi = _u.GetType().GetProperty(tpi.Name);
                if (upi != null)  
                {
                    if (!tpi.CanWrite) continue;  
                    object value = upi.GetValue(_u, null);
                    if (value != DBNull.Value && tpi.PropertyType == upi.PropertyType)
                        tpi.SetValue(t_, value, null);
                }
            }
            return t_;
        }