DataContractAttribute 類別

定義

命名空間:

System.Runtime.Serialization

組件:

System.Runtime.Serialization.Primitives.dll

來源:

DataContractAttribute.cs

指定定義或實作資料合約的型別，可由序列化程式 (例如 DataContractSerializer) 加以序列化。 型別作者一定要定義型別的資料合約，才能讓型別能夠進行序列化。

public ref class DataContractAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Enum | System.AttributeTargets.Struct, AllowMultiple=false, Inherited=false)]
public sealed class DataContractAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Enum | System.AttributeTargets.Struct, AllowMultiple=false, Inherited=false)>]
type DataContractAttribute = class
    inherit Attribute

Public NotInheritable Class DataContractAttribute
Inherits Attribute

繼承

Object

Attribute

DataContractAttribute

屬性

AttributeUsageAttribute

範例

下列範例會序列化和還原序列化名稱為 Person 且已套用 DataContractAttribute 的類別。 請注意，Namespace 和 Name 屬性的值已經設定為將覆寫預設設定。

namespace DataContractAttributeExample
{
    // Set the Name and Namespace properties to new values.
    [DataContract(Name = "Customer", Namespace = "http://www.contoso.com")]
    class Person : IExtensibleDataObject
    {
        // To implement the IExtensibleDataObject interface, you must also
        // implement the ExtensionData property.
        private ExtensionDataObject extensionDataObjectValue;
        public ExtensionDataObject ExtensionData
        {
            get
            {
                return extensionDataObjectValue;
            }
            set
            {
                extensionDataObjectValue = value;
            }
        }

        [DataMember(Name = "CustName")]
        internal string Name;

        [DataMember(Name = "CustID")]
        internal int ID;

        public Person(string newName, int newID)
        {
            Name = newName;
            ID = newID;
        }
    }

    class Test
    {
        public static void Main()
        {
            try
            {
                WriteObject("DataContractExample.xml");
                ReadObject("DataContractExample.xml");
                Console.WriteLine("Press Enter to end");
                Console.ReadLine();
            }
            catch (SerializationException se)
            {
                Console.WriteLine
                ("The serialization operation failed. Reason: {0}",
                  se.Message);
                Console.WriteLine(se.Data);
                Console.ReadLine();
            }
        }

        public static void WriteObject(string path)
        {
            // Create a new instance of the Person class and
            // serialize it to an XML file.
            Person p1 = new Person("Mary", 1);
            // Create a new instance of a StreamWriter
            // to read and write the data.
            FileStream fs = new FileStream(path,
            FileMode.Create);
            XmlDictionaryWriter writer = XmlDictionaryWriter.CreateTextWriter(fs);
            DataContractSerializer ser =
                new DataContractSerializer(typeof(Person));
            ser.WriteObject(writer, p1);
            Console.WriteLine("Finished writing object.");
            writer.Close();
            fs.Close();
        }
        public static void ReadObject(string path)
        {
            // Deserialize an instance of the Person class
            // from an XML file. First create an instance of the
            // XmlDictionaryReader.
            FileStream fs = new FileStream(path, FileMode.OpenOrCreate);
            XmlDictionaryReader reader =
                XmlDictionaryReader.CreateTextReader(fs, new XmlDictionaryReaderQuotas());

            // Create the DataContractSerializer instance.
            DataContractSerializer ser =
                new DataContractSerializer(typeof(Person));

            // Deserialize the data and read it from the instance.
            Person newPerson = (Person)ser.ReadObject(reader);
            Console.WriteLine("Reading this object:");
            Console.WriteLine(String.Format("{0}, ID: {1}",
            newPerson.Name, newPerson.ID));
            fs.Close();
        }
    }
}

Namespace DataContractAttributeExample
    ' Set the Name and Namespace properties to new values.
    <DataContract(Name := "Customer", [Namespace] := "http://www.contoso.com")>  _
    Class Person
        Implements IExtensibleDataObject
        ' To implement the IExtensibleDataObject interface, you must also
        ' implement the ExtensionData property.
        Private extensionDataObjectValue As ExtensionDataObject 
        
        Public Property ExtensionData() As ExtensionDataObject _
          Implements IExtensibleDataObject.ExtensionData
            Get
                Return extensionDataObjectValue
            End Get
            Set
                extensionDataObjectValue = value
            End Set
        End Property
        
        <DataMember(Name := "CustName")>  _
        Friend Name As String
        
        <DataMember(Name := "CustID")>  _
        Friend ID As Integer
        
        
        Public Sub New(ByVal newName As String, ByVal newID As Integer) 
            Name = newName
            ID = newID
        
        End Sub 
    End Class 
    
    
    Class Test
        
        Public Shared Sub Main() 
            Try
                WriteObject("DataContractExample.xml")
                ReadObject("DataContractExample.xml")
                Console.WriteLine("Press Enter to end")
                Console.ReadLine()
            Catch se As SerializationException
                Console.WriteLine("The serialization operation failed. Reason: {0}", _
                   se.Message)
                Console.WriteLine(se.Data)
                Console.ReadLine()
            End Try
        
        End Sub 
        
        
        Public Shared Sub WriteObject(ByVal path As String) 
            ' Create a new instance of the Person class and 
            ' serialize it to an XML file.
            Dim p1 As New Person("Mary", 1)
            ' Create a new instance of a StreamWriter
            ' to read and write the data.
            Dim fs As New FileStream(path, FileMode.Create)
            Dim writer As XmlDictionaryWriter = XmlDictionaryWriter.CreateTextWriter(fs)
            Dim ser As New DataContractSerializer(GetType(Person))
            ser.WriteObject(writer, p1)
            Console.WriteLine("Finished writing object.")
            writer.Close()
            fs.Close()
        
        End Sub 
        
        Public Shared Sub ReadObject(ByVal path As String) 
            ' Deserialize an instance of the Person class 
            ' from an XML file. First create an instance of the 
            ' XmlDictionaryReader.
            Dim fs As New FileStream(path, FileMode.OpenOrCreate)
            Dim reader As XmlDictionaryReader = XmlDictionaryReader. _
              CreateTextReader(fs, New XmlDictionaryReaderQuotas())
            
            ' Create the DataContractSerializer instance.
            Dim ser As New DataContractSerializer(GetType(Person))
            
            ' Deserialize the data and read it from the instance.
            Dim newPerson As Person = CType(ser.ReadObject(reader), Person)
            Console.WriteLine("Reading this object:")
            Console.WriteLine(String.Format("{0}, ID: {1}", newPerson.Name, newPerson.ID))
            fs.Close()
        
        End Sub 
    End Class 
End Namespace

備註

如需此 API 的詳細資訊，請參閱 DataContractAttribute 的補充 API 備註。

建構函式

DataContractAttribute()

初始化 DataContractAttribute 類別的新執行個體。

屬性

IsNameSetExplicitly	確認是否已明確設定 Name。
IsNamespaceSetExplicitly	確認是否已明確設定 Namespace。
IsReference	取得或設定值，這個值表示是否要保留物件參考資料。
IsReferenceSetExplicitly	確認是否已明確設定 IsReference。
Name	取得或設定型別的資料合約名稱。
Namespace	取得或設定型別之資料合約的命名空間。
TypeId	在衍生類別中實作時，取得這個 Attribute 的唯一識別碼。 (繼承來源 Attribute)

方法

Equals(Object)	傳回值，這個值指出此執行個體是否與指定的物件相等。 (繼承來源 Attribute)
GetHashCode()	傳回這個執行個體的雜湊碼。 (繼承來源 Attribute)
GetType()	取得目前執行個體的 Type。 (繼承來源 Object)
IsDefaultAttribute()	在衍生類別中覆寫時，表示這個執行個體的值是衍生類別的預設值。 (繼承來源 Attribute)
Match(Object)	在衍生類別中覆寫時，會傳回值，表示這個執行個體是否等於指定物件。 (繼承來源 Attribute)
MemberwiseClone()	建立目前 Object 的淺層複製。 (繼承來源 Object)
ToString()	傳回代表目前物件的字串。 (繼承來源 Object)

另請參閱

• IExtensibleDataObject
• ExtensionDataObject
• DataContractSerializer
• DataMemberAttribute
• ISerializable
• KnownTypeAttribute
• 使用資料合約