IOperationStack Interface

Provides access to members that control the Operation Stack.

Product Availability

Description

An application can implement an OperationStack to provide undo and redo facilities. As you carry out operations, they are added to the stack, then you can use undo and redo in the application to manipulate the stack to undo or redo the operations.

Members

	Name	Description
	Count	The number of operations on the stack.
	Do	Performs the given operation and places it on the stack.
	Item	The operation at the specified index.
	Redo	Redoes the next operation on the stack.
	RedoOperation	Redoes a specified operation.
	Remove	Removes an operation from the stack.
	Reset	Removes all operations from the stack.
	Undo	Undoes the previous operation on the stack.
	UndoOperation	Undoes a specified operation.

Classes that implement IOperationStack

Remarks

ArcMap has an OperationStack, which can be obtained with the IMxDocument::OperationStack property. ArcMap’s buttons and tools wrap their actions in an operation and add the operations to the stack.

Depending on your scenario, there are different methodologies for creating an operation and adding it to the OperationStack.

• If your tool edits features and rows, you can use IEditor::StartOperation, and IEditor::StopOperation and the actions in between will be automatically added to the OperationStack as a single operation. Stopping an edit session clears the OperationStack.
• If you are outside an editsession and updating a geodatabase directly, calls to IWorkspaceEdit::StartEditOperation and StopEditOperation will not automatically add anything to ArcMap’s OperationStack since these interfaces are independent of ArcMap, and these changes will be made directly to the geodatabase.
• For other actions, for example on graphic elements, you need to create a custom operation object that implements IOperation. The operation is executed and loaded onto the stack with a call to IOperationStack::Do.