Create menu file

You can't go directly to layout Create a new one under the file XML file , In that case, there would be no item Identification of the , There will be no prompts provided by the system

stay res Right click under file to create a new Android resource directory

And then in type Choose from menu

Then it will automatically generate a... Under the resource file menu Folder , Create a new... In this folder XML Just the documents

This is the time to write item ID There will be a prompt provided by the system .