Gets or sets a value that specifies whether to serialize the default value for a field or property being serialized.
Assembly: System.Runtime.Serialization (in System.Runtime.Serialization.dll)
'Declaration Public Property EmitDefaultValue As Boolean 'Usage Dim instance As DataMemberAttribute Dim value As Boolean value = instance.EmitDefaultValue instance.EmitDefaultValue = value
Property ValueType: System.Boolean
true if the default value for a member should be generated in the serialization stream; otherwise, false. The default is true.
In the .NET Framework, types have a concept of default values. For example, for any reference type the default value is Nothing, 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 property to false (it is true by default).
Setting the property to false is not a recommended practice. It should only be done if there is a specific need to do so (such as for interoperability or to reduce data size).
The following example shows the property set to false on various fields.
<DataContract()> _ Public Class Employee ' The CLR default for as string is a null value. ' This will be written as <employeeName xsi:nil="true" /> <DataMember()> _ Public employeeName As String = Nothing ' This will be written as <employeeID>0</employeeID> <DataMember()> _ Public employeeID As Integer = 0 ' The next two will not be written because the EmitDefaultValue = false. <DataMember(EmitDefaultValue := False)> Public position As String = Nothing <DataMember(EmitDefaultValue := False)> Public salary As Integer = 0 ' This will be written as <targetSalary>555</targetSalary> because ' the 555 does not match the .NET default of 0. <DataMember(EmitDefaultValue := False)> Public targetSalary As Integer = 555 End Class
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.