/// <summary>
/// This method attaches or detaches the "TabbedInspector" class extension to/from the specified
/// feature class. If the featureclass already has an extension class, and it isn't the 'TabbedInspector' extension,
/// the method does not modify the class extension.
/// </summary>
/// <param name="fc">The feature class to be altered.</param>
/// <returns>Whether the operation succeeded (successful detach or attach).</returns>
bool AlterClassExtension(IFeatureClass fc)
{
// Attempt to get access to schema-editing functionality on the feature class
IClassSchemaEdit classSchemaEdit = fc as IClassSchemaEdit;
if (classSchemaEdit == null)
{
m_appServices.SetStatusMessage("The selected feature class doesn't support attaching an extension class.", true);
return(false);
}
// Create a UID object holding the TabbedInspector's CLSID
UID classUID = new UIDClass();
classUID.Value = "{" + TabbedInspector.TabbedInspectorCLSID + "}";
// Do the schema update within a schema lock.
bool succeeded = false;
DoInSchemaLock(fc, delegate
{
// Does the feature class already have an extension class associated with it?
if (fc.EXTCLSID != null)
{
// The featureclass already has an extension attached.
if (fc.EXTCLSID.Value.Equals(classUID.Value))
{
// The extension is the TabbedInspector extension. Detach it.
classSchemaEdit.AlterClassExtensionCLSID(null, null);
m_appServices.SetStatusMessage(
string.Format("The 'custom inspector' extension class was detached from {0}.", fc.AliasName), false);
succeeded = true;
}
else
{
//Don't mess with featureclasses that have some other existing extension class associated with them.
m_appServices.SetStatusMessage(
string.Format("{0} already has another extension class attached to it. No change was made.", fc.AliasName), true);
succeeded = false;
}
}
else
{
// There is no extension attached to the featureclass. Attach the TabbedInspector extension.
classSchemaEdit.AlterClassExtensionCLSID(classUID, null);
m_appServices.SetStatusMessage(
string.Format("The 'custom inspector' extension class was attached to {0}.", fc.AliasName), false);
succeeded = true;
}
});
return(succeeded);
}
public void IClassSchemaEdit_Example(IObjectClass objectClass)
{
//This function shows how you can use the IClassSchemaEdit
//interface to alter the COM class extension for an object class.
//cast for the IClassSchemaEdit
IClassSchemaEdit classSchemaEdit = (IClassSchemaEdit)objectClass;
//set and exclusive lock on the class
ISchemaLock schemaLock = (ISchemaLock)objectClass;
schemaLock.ChangeSchemaLock(esriSchemaLock.esriExclusiveSchemaLock);
ESRI.ArcGIS.esriSystem.UID classUID = new ESRI.ArcGIS.esriSystem.UIDClass();
//GUID for the C# project.
classUID.Value = "{65a43962-8cc0-49c0-bfa3-015d0ff8350e}";
classSchemaEdit.AlterClassExtensionCLSID(classUID, null);
//release the exclusive lock
schemaLock.ChangeSchemaLock(esriSchemaLock.esriSharedSchemaLock);
}
