public void ResetContextMenu() { contextMenuStrip.InvokeIfRequired(() => { contextMenuStrip.Items.DisposeItems(); contextMenuStrip.Items.Clear(); ToolStripMenuItem deleteMenuItem = contextMenuStrip.AddItem <ToolStripMenuItem>(MENU_ITEM_DELETE); foreach (File file in Folder.Files) { deleteMenuItem.AddItem <ToolStripMenuItem>(file.Name, DeleteMenuItem_Click, file); } contextMenuStrip.AddItem <ToolStripMenuItem>(MENU_ITEM_DELETE_ALL, DeleteAllMenuItem_Click); }); }