CustomFieldDefinition Class

Represents a field that can be used to identify an item in the metadata store or to store version-related information for an item or a change unit.

Namespace: Microsoft.Synchronization.SimpleProviders
Assembly: Microsoft.Synchronization.SimpleProviders (in microsoft.synchronization.simpleproviders.dll)

Syntax

'Declaration
Public Class CustomFieldDefinition
'Usage
Dim instance As CustomFieldDefinition

public class CustomFieldDefinition

public ref class CustomFieldDefinition

public class CustomFieldDefinition

public class CustomFieldDefinition

Remarks

Custom fields are fields in the metadata store that are identified by integers. If an application requires a friendly name for one or more fields, it should map the integer to a name. Custom fields are defined for two reasons: to identify items, and to provide version information about those items. Version fields enable Sync Framework to determine if an item or change unit has changed. For more information about simple provider metadata, see Managing Metadata for Simple Providers.

Custom fields can be of the following data types. For fixed length types, use the two-parameter constructor CustomFieldDefinition. For variable length types, use the three-parameter constructor CustomFieldDefinition.

Type	Constructor
Byte	CustomFieldDefinition
Byte[]	CustomFieldDefinition
Guid	CustomFieldDefinition
String	CustomFieldDefinition
UInt16	CustomFieldDefinition
UInt32	CustomFieldDefinition
UInt64	CustomFieldDefinition

Example

The following code examples provide input for the ItemMetadataSchema object. The constants in the sample code define an integer value for each column in the item store. These values are used when creating the custom field definitions and identity rules for the ItemMetadataSchema object. To view this code in the context of a complete application, see the "Sync101 using Simple Sync Provider" application that is available in the Sync Framework SDK and from Code Gallery.

public const uint CUSTOM_FIELD_ID = 1;
public const uint CUSTOM_FIELD_TIMESTAMP = 2;

public override ItemMetadataSchema MetadataSchema
{
    get
    {
        CustomFieldDefinition[] customFields = new CustomFieldDefinition[2];
        customFields[0] = new CustomFieldDefinition(CUSTOM_FIELD_ID, typeof(ulong));
        customFields[1] = new CustomFieldDefinition(CUSTOM_FIELD_TIMESTAMP, typeof(ulong));

        IdentityRule[] identityRule = new IdentityRule[1];
        identityRule[0] = new IdentityRule(new uint[] { CUSTOM_FIELD_ID });

        return new ItemMetadataSchema(customFields, identityRule);
    }
}

Public Const CUSTOM_FIELD_ID As UInteger = 1
Public Const CUSTOM_FIELD_TIMESTAMP As UInteger = 2
Public Overrides ReadOnly Property MetadataSchema() As ItemMetadataSchema
    Get
        Dim customFields As CustomFieldDefinition() = New CustomFieldDefinition(1) {}
        customFields(0) = New CustomFieldDefinition(CUSTOM_FIELD_ID, GetType(ULong))
        customFields(1) = New CustomFieldDefinition(CUSTOM_FIELD_TIMESTAMP, GetType(ULong))

        Dim identityRule As IdentityRule() = New IdentityRule(0) {}
        identityRule(0) = New IdentityRule(New UInteger() {CUSTOM_FIELD_ID})

        Return New ItemMetadataSchema(customFields, identityRule)
    End Get
End Property

Inheritance Hierarchy

System.Object
  Microsoft.Synchronization.SimpleProviders.CustomFieldDefinition

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

CustomFieldDefinition Members
Microsoft.Synchronization.SimpleProviders Namespace