# WindowBase

**Inheritance:** [TopLevel](https://api.fabulous.dev/avalonia/toplevel)\
AvaloniaUI **documentation:** WindowBase [API](https://reference.avaloniaui.net/api/Avalonia.Controls/WindowBase/)

## Properties

| Properties           | Description                |
| -------------------- | -------------------------- |
| topmost(value: bool) | Sets the Topmost property. |

## Events

| Properties                                         | Description                                 |
| -------------------------------------------------- | ------------------------------------------- |
| onActivated(msg: 'msg)                             | Raised when the window is activated.        |
| onDeactivated(msg: 'msg)                           | Raised when the window is deactivated.      |
| onPositionChanged(fn: PixelPointEventArgs -> 'msg) | Raised when the window position is changed. |
| onResized(fn: WindowResizedEventArgs -> 'msg)      | Raised when the window is resized.          |