# ContentUndoHelper class

Namespace: [Rhino.Render](https://developer.rhino3d.com/api/rhinocommon/namespace/rhino.render.md) · Assembly: [RhinoCommon](https://developer.rhino3d.com/api/rhinocommon/assembly/rhinocommon.md)

```cs
public class ContentUndoHelper : IDisposable
```

Content undo helper to be used with "using {}" to enclose a block of changes.

## Constructors

- [ContentUndoHelper](https://developer.rhino3d.com/api/rhinocommon/type/rhino.render.contentundohelper/ctor.md): (2 overloads) DEPRECATED: Constructs a ContentUndoHelper object inside a using block to handle undo when modifying a RenderContent or - alternatively - create the ContentUndoHelper and explicitly call Dispose when you are done.

## Finalizer

- [~ContentUndoHelper](https://developer.rhino3d.com/api/rhinocommon/type/rhino.render.contentundohelper/finalize.md)

## Methods

- [AddContent](https://developer.rhino3d.com/api/rhinocommon/type/rhino.render.contentundohelper/addcontent.md): Call this *after* adding a content. Undo will cause the content to be deleted.
- [Dispose](https://developer.rhino3d.com/api/rhinocommon/type/rhino.render.contentundohelper/dispose.md): (2 overloads)
- [ModifyContent](https://developer.rhino3d.com/api/rhinocommon/type/rhino.render.contentundohelper/modifycontent.md): Call this before modifying or deleting a content. Undo will cause the content to be restored.
- [TweakContent](https://developer.rhino3d.com/api/rhinocommon/type/rhino.render.contentundohelper/tweakcontent.md): Call this before tweaking a single content parameter. Undo will cause the parameter to be restored.