Creating a file is so simple, I thought it was really easy, but it turned out to be not so simple in android studio
Let me tell you about my mistakes:
1. Create a diretory under res, just create a folder according to your own idea
After creation, you will find the created XML, even if it is written according to menu, the system will prompt
The system will prompt that there are no such labels.
So it must be that the previous method of creating folders and files is irregular.
2. Solutions
(1) Right-click the res folder first, as shown below, to create a resource directory
In the pop-up page, select the corresponding menu type
Then click OK, then the menu folder is created.
(2) Create the xml file of the menu, right-click in the menu folder, and select Create menu resource file, as shown below
Just enter the file name. Then the menu xml file as shown below can be edited.
Learning is important, don't use previous experience to write Android.