VM332 WAService. js:2 Error: _ vm. Changetabs is not a function

VM332 WAService.js:2 Error: _vm.changeTabs is not a function Report errors , Tab error , After searching for a long time, I didn't find any code errors , The words are right after checking one by one ：

Where to check ：1. Spelling of words ,

2. Whether there are multiple method names @

3.methods Did you write more

4. Is the method in methods Inside ,

5.data Whether there is a subscript in it

The final inspection found that , I wrote two methods, Result in an error ......

end .......