如何确保为通过Web服务公开的类的属性设置初始值

Question

I have a class which initializes its properties in its constructor.

public class Criteria
{
    public bool Chapter1 { get; set; }
    public bool Chapter2 { get; set; }
    ...
    public uint MaxResults { get; set; }
    public int Hits { get; set; }

    public Criteria()
    {
        Chapter1 = false;
        Chapter2 = false;
        ...
        MaxResults = 100;
        Hits = -1;
    }
}

This class is used internally within a web-service to configure searches on a DB. When I construct the class internally, the correct initialization is performed and operation is as anticipated.

However, the class is also exposed as a parameter in a Method to this Web-Service :

    [WebMethod]
    public List<xxx> GetxxxCollection(string requestingUserName, Criteria sc)
    {
      ...
    }

Prior to the clients call to this web-service, the Criteria object is constructed and configured. But, because its exposed through the web-service, the constructor is not actually called and the client does not always set all required values correctly.

Given that we have limited control over the client code, Whats the best strategy to ensure that appropriate initial values are set ?

Answer 1

You cannot control the client in any way. The "Service" class on the client is in no way related to the service class that contains the constructor. It's just a "proxy" class, not the real thing.

Answer 2

也许您可以使用nullable为nullable字段，以便您知道客户端尚未在这些字段中设置任何值。

Answer 3

Don't use auto-implemented properties in your class, but instead use the old manual properties with backing-fields which might be initialized by default without a constructor invocation:

public class Criteria
{
  private int _maxResults = 100;

  //-----------------------------------------------------------------------

  public int MaxResults
  {
    get{ return _maxResult; }
    set{ _maxResults = value; }
  }

}