WorkflowWindowsFormsModule.QueryAvailableActivities Event

Occurs prior to loading the rehosted workflow designer.

Namespace: DevExpress.ExpressApp.Workflow.Win

Assembly: DevExpress.ExpressApp.Workflow.Win.v20.2.dll

NuGet Package: DevExpress.ExpressApp.Workflow.Win

Declaration

C#

public event EventHandler<ActivitiesInformationEventArgs> QueryAvailableActivities

VB.NET

Public Event QueryAvailableActivities As EventHandler(Of ActivitiesInformationEventArgs)

Event Data

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

Property	Description
ActivitiesInformation	Specifies activities that will be available in the rehosted workflow designer’s toolbox.

Remarks

Handle this event to customize the list of activities that will be available in the rehosted workflow designer’s toolbox. The following code snippet demonstrates how to remove a MyActivity activity from the toolbox.

C#

using System;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Workflow;
using DevExpress.ExpressApp.Workflow.Win;
//...
public class MyWindowController : WindowController {
    WorkflowWindowsFormsModule workflowModuleWin;
    protected override void OnActivated() {
        base.OnActivated();
        workflowModuleWin = Application.Modules.FindModule<WorkflowWindowsFormsModule>();
        if (workflowModuleWin != null)
            workflowModuleWin.QueryAvailableActivities += OnQueryAvailableActivities;
    }
    void OnQueryAvailableActivities(object sender, ActivitiesInformationEventArgs e) {
        ActivityInformation myActivity = 
            e.ActivitiesInformation.Find(i => i.DisplayName == "MyActivity");
        e.ActivitiesInformation.Remove(myActivity);
    }
    protected override void OnDeactivated() {
        if (workflowModuleWin != null) {
            workflowModuleWin.QueryAvailableActivities -= OnQueryAvailableActivities;
            workflowModuleWin = null;
        }
        base.OnDeactivated();
    }
}

VB.NET

Imports System
Imports DevExpress.ExpressApp
Imports DevExpress.ExpressApp.Workflow
Imports DevExpress.ExpressApp.Workflow.Win
'...
Public Class MyWindowController
    Inherits WindowController
    Private workflowModuleWin As WorkflowWindowsFormsModule
    Protected Overrides Sub OnActivated()
        MyBase.OnActivated()
        workflowModuleWin = Application.Modules.FindModule(Of WorkflowWindowsFormsModule)()
        If workflowModuleWin IsNot Nothing Then
            AddHandler workflowModuleWin.QueryAvailableActivities, _
            AddressOf OnQueryAvailableActivities
        End If
    End Sub
    Private Sub OnQueryAvailableActivities(ByVal sender As Object, _
    ByVal e As ActivitiesInformationEventArgs)
        Dim myActivity As ActivityInformation = _
        e.ActivitiesInformation.Find(Function(i) i.DisplayName = "MyActivity")
        e.ActivitiesInformation.Remove(myActivity)
    End Sub
    Protected Overrides Sub OnDeactivated()
        If workflowModuleWin IsNot Nothing Then
            RemoveHandler workflowModuleWin.QueryAvailableActivities, _
            AddressOf OnQueryAvailableActivities
            workflowModuleWin = Nothing
        End If
        MyBase.OnDeactivated()
    End Sub
End Class

To see an example of handling this event to add new activities to the toolbox, refer to the Add Activities to the Workflow Designer Toolbox help topic.