IChangeDataRetriever.LoadChangeData Method
When overridden in a derived class, this method retrieves item data for a change.
Namespace: Microsoft.Synchronization
Assembly: Microsoft.Synchronization (in Microsoft.Synchronization.dll)
Syntax
'Declaration
Function LoadChangeData ( _
loadChangeContext As LoadChangeContext _
) As Object
'Usage
Dim instance As IChangeDataRetriever
Dim loadChangeContext As LoadChangeContext
Dim returnValue As Object
returnValue = instance.LoadChangeData(loadChangeContext)
Object LoadChangeData(
LoadChangeContext loadChangeContext
)
Object^ LoadChangeData(
LoadChangeContext^ loadChangeContext
)
abstract LoadChangeData :
loadChangeContext:LoadChangeContext -> Object
function LoadChangeData(
loadChangeContext : LoadChangeContext
) : Object
Parameters
- loadChangeContext
Type: Microsoft.Synchronization.LoadChangeContext
Metadata that describes the change for which data should be retrieved.
Return Value
Type: System.Object
The item data for the change.
Remarks
The source provider determines the type of object that is returned by this method. The object can be as simple as a boxed value type or as complex as a class that contains methods for advanced data retrieval.
Examples
The following example shows how to implement the LoadChangeData method to retrieve the data for a specified set of change units. This example returns the data as a sparsely-populated array of strings.
Public Function LoadChangeData(ByVal loadChangeContext As LoadChangeContext) As Object Implements IChangeDataRetriever.LoadChangeData
' Sanity check to ensure the data array is not overrun.
If Contact.ChangeUnitFieldCount < loadChangeContext.ItemChange.ChangeUnitChanges.Count Then
Throw New ArgumentOutOfRangeException("LoadChangeData received too many change unit changes.")
End If
' Get the ID of the item to return.
Dim itemId As SyncId = loadChangeContext.ItemChange.ItemId
' Create a string array to hold the data for each change unit. Some of the elements of this array
' may be empty.
Dim contactData As String() = New String(Contact.ChangeUnitFieldCount - 1) {}
' Enumerate the change units to retrieve.
For iChange As Integer = 0 To loadChangeContext.ItemChange.ChangeUnitChanges.Count - 1
' Retrieve data for the specified change unit and put the data into the appropriate
' place in the string array.
Dim icu As Integer = loadChangeContext.ItemChange.ChangeUnitChanges(iChange).ChangeUnitId.GetByteId()
contactData(icu) = _ContactStore.GetContactData(itemId, loadChangeContext.ItemChange.ChangeUnitChanges(iChange).ChangeUnitId)
Next
Return contactData
End Function
public object LoadChangeData(LoadChangeContext loadChangeContext)
{
// Sanity check to ensure the data array is not overrun.
if (Contact.ChangeUnitFieldCount < loadChangeContext.ItemChange.ChangeUnitChanges.Count)
{
throw new ArgumentOutOfRangeException("LoadChangeData received too many change unit changes.");
}
// Get the ID of the item to return.
SyncId itemId = loadChangeContext.ItemChange.ItemId;
// Create a string array to hold the data for each change unit. Some of the elements of this array
// may be empty.
string[] contactData = new string[Contact.ChangeUnitFieldCount];
// Enumerate the change units to retrieve.
for (int iChange = 0; iChange < loadChangeContext.ItemChange.ChangeUnitChanges.Count; iChange++)
{
// Retrieve data for the specified change unit and put the data into the appropriate
// place in the string array.
int icu = loadChangeContext.ItemChange.ChangeUnitChanges[iChange].ChangeUnitId.GetByteId();
contactData[icu] = _ContactStore.GetContactData(itemId,
loadChangeContext.ItemChange.ChangeUnitChanges[iChange].ChangeUnitId);
}
return contactData;
}