[Vuejs]-How to make VS Code give problem indicators for unused parameters?

Since in your tags you indicate that you are using TypeScript, you can use the noUnusedParameters tsconfig setting. Quoting from the setting’s docs:

Report errors on unused parameters in functions.

Like so in the tsconfig.json:

{
  ...
  "compilerOptions": {
    ...
    "noUnusedParameters": true,
    ...
  }
  ...
}

Or, as indicated in the comments by @kissu, you could use ESLint. For some tips on setup, see Vue 2 – ESLint + Standard + Prettier.