The OnFileSelected field is an event handler that is triggered when a file is selected in the AssetBrowser. This selection can occur through a double-click or by pressing the enter key. The event handler is of type System.Action<System.String>, meaning it takes a single string parameter, which represents the path or identifier of the selected file.

To use the OnFileSelected event, you need to assign a method that matches the signature void MethodName(string filePath) to it. This method will be called whenever a file is selected in the AssetBrowser.

Example usage:

AssetBrowser assetBrowser = new AssetBrowser();
assetBrowser.OnFileSelected += (filePath) => {
    // Handle the file selection
    // For example, open the file or display its properties
    OpenFile(filePath);
};