特性,元数据

   public class Employee
    {
        // 只有SourceType== Salary 才转账
        public void TransferToEmployee([TransferSource(TransferType = TransferSourceType.Salary)]int number)
        {
            //汇钱到银行卡
        }
    }
    /// <summary>
    /// 转账类型
    /// </summary>
    public enum TransferSourceType
    {
        Salary,
        Reimburse,
        Loan
    }

  public class HR
    {
        public void ToSalary(Employee employee)
        {
// 使用元数据
            var transferSource = typeof(Employee).GetMethod("TransferToEmployee").GetParameters()[0].GetCustomAttributes(false)[0] as TransferSource;
            if (transferSource.TransferType == TransferSourceType.Salary)
            {
                employee.TransferToEmployee(500);
            }
            else
            {
                employee.TransferToEmployee(0);
            }
        }
    }

        Employee employee = new Employee();
            HR hr = new HR();
            hr.ToSalary(employee);