SchedulerDataStorage.ResourceCollectionAutoReloading Event

Occurs when the data source which contains resources is modified and the automatic reloading of resources is enabled.

Namespace: DevExpress.XtraScheduler

Assembly: DevExpress.XtraScheduler.v23.2.dll

NuGet Package: DevExpress.Win.Scheduler

Declaration

C#

public event CancelListChangedEventHandler ResourceCollectionAutoReloading

VB.NET

Public Event ResourceCollectionAutoReloading As CancelListChangedEventHandler

Event Data

The ResourceCollectionAutoReloading event's data class is CancelListChangedEventArgs. The following properties provide information specific to this event:

Property	Description
Cancel	Gets or sets whether the operation performed on the processed event should be canceled.
ListChangedType	Gets the type of change. Inherited from ListChangedEventArgs.
NewIndex	Gets the index of the item affected by the change. Inherited from ListChangedEventArgs.
OldIndex	Gets the old index of an item that has been moved. Inherited from ListChangedEventArgs.
PropertyDescriptor	Gets the PropertyDescriptor that was added, changed, or deleted. Inherited from ListChangedEventArgs.

Remarks

You can use the DataMember and DataSource properties of the ResourceStorageBase object to bind the SchedulerDataStorage object to the data source which contains resources for appointments. In this case, resources will be automatically obtained from the specified data source.

When the PersistentObjectStorage<T>.AutoReload property of the ResourceStorageBase object is set to true, the data is automatically reloaded. In this case, the SchedulerDataStorage object reloads data from the data source each time an item in the data source is modified, added, moved or removed, a column is added, modified or deleted or multiple changes are made to the data source. The SchedulerDataStorage.ResourceCollectionAutoReloading event allows you to prevent data from being reloaded in specific cases. Use the event’s ListChangedType parameter to determine the reason for the data source changes. To prevent data from being reloaded in a specific case set the Cancel parameter to true. Otherwise, the scheduler storage object will always reload data from the data source immediately after the event handler has completed.

The ResourceCollectionAutoReloading event doesn’t fire in the following cases:

• The data source which contains resources is not connected to the SchedulerDataStorage object.
• The PersistentObjectStorage<T>.AutoReload property is set to false.

Example

In the following example the SchedulerDataStorage.AppointmentCollectionAutoReloading and SchedulerDataStorage.ResourceCollectionAutoReloading events are handled to prevent appointments and appointment resources from being reloaded from a data source in the following cases:

• When a data source item (row) is being moved to a new position.
• When a column (field) is added, modified or deleted in the data source.

C#

 using System.ComponentModel;
 using DevExpress.XtraScheduler;
 // ...

 // Subscribe to the event which controls data reloading 
 // for the data source which contains appointments.
 schedulerControl.DataStorage.AppointmentCollectionAutoReloading += 
    new CancelListChangedEventHandler(OnCollectionAutoReloading);

 // Subscribe to the event which controls data reloading 
 // for the data source which contains appointment resources.
 schedulerControl.DataStorage.ResourceCollectionAutoReloading += 
    new CancelListChangedEventHandler(OnCollectionAutoReloading);


 private void OnCollectionAutoReloading(object sender, 
    CancelListChangedEventArgs e) {
    // Prevent data reloading when the data source is modified in specific cases.
    if(e.ListChangedType == ListChangedType.ItemMoved || e.ListChangedType == 
        ListChangedType.PropertyDescriptorAdded || 
        e.ListChangedType == ListChangedType.PropertyDescriptorChanged || 
        e.ListChangedType == ListChangedType.PropertyDescriptorDeleted)
       e.Cancel = true;
 }

VB.NET

Imports System.ComponentModel
Imports DevExpress.XtraScheduler
' ...

' Subscribe to the event which controls data reloading 
' for the data source which contains appointments.
AddHandler SchedulerDataStorage1.AppointmentCollectionAutoReloading,  _
    New CancelListChangedEventHandler(AddressOf OnCollectionAutoReloading)

' Subscribe to the event which controls data reloading 
' for the data source which contains appointment resources.
AddHandler SchedulerDataStorage1.ResourceCollectionAutoReloading,  _
    New CancelListChangedEventHandler(AddressOf OnCollectionAutoReloading)

Sub OnCollectionAutoReloading(ByVal sender As Object,  _
    ByVal e As CancelListChangedEventArgs)
   ' Prevent data reloading when the data source is modified in specific cases.
   If e.ListChangedType = ListChangedType.ItemMoved Or  _
    e.ListChangedType = ListChangedType.PropertyDescriptorAdded Or  _
    e.ListChangedType = ListChangedType.PropertyDescriptorChanged Or  _
    e.ListChangedType = ListChangedType.PropertyDescriptorDeleted Then
      e.Cancel = True
   End If
End Sub