Prerequisite
If you want to add a UBIK Workflow Activity via the UBIK Injection Interface to UBIK your Activity needs to be a UBIK Plugin. See here how to create your own Plugin.
Workflow
Further more your Plugin should implement the Ubik UBIK.WorkflowBase.IUBIKActivity (but there is no technical need to do it). Therefor, you need a reference to UBIK.WorkflowBase.
Example:
[Export(typeof(UBIK.Injection.IUbikPlugin))]
[ExportMetadata("ID", "23B72354-A26F-449E-A7DA-F874B4167248")]
[ExportMetadata("Type", typeof(myWorkflowActivity))]
[ExportMetadata("Name", "my WorkflowActivity")]
[ExportMetadata("Description", "does fancy things in version 2.4")]
[ExportMetadata("Version", 3)]
[ExportMetadata("MinimumKernelVersion", "2.4.0.0")]
[ExportMetadata("MinimumDatabaseVersion", "2.4.0.0")]
public class myWorkflowActivity : UBIK.Injection.IUbikPlugin, UBIK.WorkflowBase.IUBIKActivity
{
}
[ExportMetadata("ID", "23B72354-A26F-449E-A7DA-F874B4167248")]
[ExportMetadata("Type", typeof(myWorkflowActivity))]
[ExportMetadata("Name", "my WorkflowActivity")]
[ExportMetadata("Description", "does fancy things in version 2.4")]
[ExportMetadata("Version", 3)]
[ExportMetadata("MinimumKernelVersion", "2.4.0.0")]
[ExportMetadata("MinimumDatabaseVersion", "2.4.0.0")]
public class myWorkflowActivity : UBIK.Injection.IUbikPlugin, UBIK.WorkflowBase.IUBIKActivity
{
}