WCF服务的默认值 [英] WCF Service default values

问题描述

我有以下的数据合同类为我的WCF服务：

I have following data contract class for my WCF Service:

[DataContract(Name = "MyClassDTO")]
public class MyClass
{
    private string name = "Default Name";

    [DataMember]
    public string Name
    {
        get { return name; }
        set { name = value; }
    }
}

当我使用Visual Studio的添加服务引用函数生成一个WCF服务引用生成的DataContract看起来是这样的：

When I use Visual Studio's Add Service Reference function to generate a WCF Service Reference the generated DataContract looks something like this:

[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
[System.Runtime.Serialization.DataContractAttribute(Name = "MyClassDTO", Namespace = "xxx")]
[System.SerializableAttribute()]
public partial class MyClassDTO : object, System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged
{

    [System.Runtime.Serialization.OptionalFieldAttribute()]
    private string NameField;

    [System.Runtime.Serialization.DataMemberAttribute()]
    public string Name
    {
        get
        {
            return this.NameField;
        }
        set
        {
            if ((object.ReferenceEquals(this.NameField, value) != true))
            {
                this.NameField = value;
                this.RaisePropertyChanged("Name");
            }
        }
    }
}

这意味着，默认值为默认名称丢失和出现以下行为：

That means, the default value "Default Name" gets lost and following behavior occurs:

MyClassDTO mcdto = new MyClassDTO();
serviceClient.DoSomething(mcdto);


[OperationContract]
void DoSomething(MyClass mc){
   mc.Name //<--   == null    but I want it to be "Default Name"
}

有没有办法配置数据契约的方式，该定义的默认值默认名称不迷路？

Is there a way configure the data contract that way, that the defined default value "Default Name" doesn't get lost?

其他信息： 我使用的服务引用的不的类型中引用大会的再利用，如在客户端MyClass类*的 DTO 的*会产生一个不知道在服务器端类的MyClass

additional information: I use a service reference without reuse of types in referenced assemblys, e.g. on the client side the class MyClass*DTO* is generated an is not aware of the server side class MyClass

推荐答案

我发现的唯一的可能（但丑陋的，因此没有真正令人满意的）解决方案，这一步是使用 OnDeserializing 属性的反序列化的开始来设置默认值的使用字段的设定器，以确定是否所传送的值应真的被设置

The only possible (but ugly and therefore not really satisfying) solution I found this far is using the OnDeserializing attribute to set the default values at the start of the deserialization an use the setter of a field to determine if the communicated value should realy be set.

   [DataContract(Name = "MyClassDTO")]
    public class MyClass
    {
        private string name;

        public MyClass()
        {
            Init();
        }

        [DataMember]
        public string Name
        {
            get{ return name; }
            set
            {
                if (!String.IsNullOrEmpty(value))
                {
                    name = value;
                }
            }
        }

        private void Init()
        {
            name = "Default Name";
        }

        [System.Runtime.Serialization.OnDeserializing]
        private void OnDeserializing(StreamingContext ctx)
        {
            Init();
        }
  }

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