DataMemberAttribute.EmitDefaultValue Property

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Gets or sets a value that specifies whether to serialize the default value for a field or property being serialized.

Namespace:  System.Runtime.Serialization
Assembly:  System.Runtime.Serialization (in System.Runtime.Serialization.dll)

public bool EmitDefaultValue { get; set; }

Property Value

Type: System.Boolean
true if the default value for a member should be generated in the serialization stream; otherwise, false. The default is true.

In .NET Framework, types have a concept of default values. For example, for any reference type the default value is null (Nothing in Visual Basic), and for an integer type it is 0. It is occasionally desirable to omit a data member from the serialized data when it is set to its default value. To do this, set the EmitDefaultValue property to false (it is true by default).


Setting the EmitDefaultValue property to false is not a recommended practice. It should be done only if there is a specific requirement to do so (such as for interoperability or to reduce data size).

	    // Define the data contract.
    	[DataContract(Name = "Customer" , Namespace = "" ) ]
    	public class User
        	[DataMember(Name = "Last" , EmitDefaultValue = true , IsRequired = true , Order = 2 )]
       		public string Name { get; set; }

        	[DataMember(Order = 1)]
        	public int Age { get; set; }

        	public User() { }

        	public User(string newName, int newAge)
            		Name = newName;
            		Age = newAge;

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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