# Refresh(string)

> Notify the main toolbar to update the content or behaviour of a toolbar element.

## Definition

* **Type:** Method
* **Namespace:** [UnityEditor.Toolbars](/engine/6000.7/script-reference/unityeditor/toolbars.md)
* **Assembly:** UnityEditor.CoreModule

```csharp
public static void Refresh(string path)
```

### Parameters

**** (\[string]\(https\://learn.microsoft.com/dotnet/api/system.string)): Unique identifier path of the element to refresh. See [MainToolbarElementAttribute.path](/engine/6000.7/script-reference/unityeditor/toolbars/maintoolbarelementattribute/path.md).

### Remarks

To update the toolbar element the toolbar queryies the [MainToolbarElement](/engine/6000.7/script-reference/unityeditor/toolbars/maintoolbarelement.md) descriptor again from the [MainToolbarElementAttribute](/engine/6000.7/script-reference/unityeditor/toolbars/maintoolbarelementattribute.md) tagged static method that has the same path.

```csharp
using UnityEditor;
using UnityEditor.Toolbars;
using UnityEngine;

public class MainToolbarToggleExample
{
 const string kElementPath = "Examples/Toggle Scene Visibility";

 [MainToolbarElement(kElementPath, defaultDockPosition = MainToolbarDockPosition.Middle)]
 public static MainToolbarElement CreateSceneViewGridToggle()
 {
 bool showGrid = SceneView.lastActiveSceneView is not null && SceneView.lastActiveSceneView.showGrid;

 var onIcon = EditorGUIUtility.IconContent("d_scenevis_visible").image as Texture2D;
 var offIcon = EditorGUIUtility.IconContent("d_scenevis_hidden").image as Texture2D;
 // We can change the content based on the internal state we want represented e.g. showGrid
 var icon = showGrid ? onIcon : offIcon;
 var content = new MainToolbarContent("Show Grid", icon, "Toggle grid visibility");

 return new MainToolbarToggle(content, showGrid, ToggleSceneGrid);
 }

 static void ToggleSceneGrid(bool value)
 {
 // The MainToolbarToggle does not keep its own state. It notifies this user code via
 // our ToggleSceneGrid callback, and it is the user's responsibility to update their
 // internal state and refresh the UI.
 if (SceneView.lastActiveSceneView is not null)
 SceneView.lastActiveSceneView.showGrid = value;
 MainToolbar.Refresh(kElementPath);
 }

 static void SceneViewChanged(SceneView oldScene, SceneView newScene)
 {
 // Scene grid visibility can be changed elsewhere such as in the Scene view. 
 // If that happens we want to be notified in order to refresh the UI to match.
 // Since CreateSceneViewGridToggle checks the internal state to match the UI content it produces,
 // we only need to call MainToolbar.Refresh with the matching path, but we will just use ToggleSceneGrid
 // for simplicity.
 if (oldScene != null)
 oldScene.gridVisibilityChanged -= ToggleSceneGrid;
 if (newScene != null)
 newScene.gridVisibilityChanged += ToggleSceneGrid;
 }

 static MainToolbarToggleExample()
 {
 SceneView.lastActiveSceneViewChanged += SceneViewChanged;
 }
}
```

The state of a `MainToolbarElements` only changes when a user updates the state. To do this, callbacks tell the user when to update their state as a result of UI interaction, for example when they select a toggle. Then, call `MainToolbar.Refresh` to update the UI to match the new state. You can call `MainToolbar.Refresh` whenever the state changes. For example, when the state changes internally and not as a result of UI interaction.