Android, 자동로그인 SharedPreference

1. 자동로그인 저옵가 저장되는 경로: /data/data/{packageName}/shared_prefs/{keyName}.xml

→ Device file explore에서 찾는다.

2. activity

private lateinit var sharedPreferences : SharedPreferences
	private lateinit var editor: SharedPreferences.Editor

	override fun onCreate(savedInstanceState: Bundle?){
		sharedPreferences = getSharePreferences("loginInfo", MODE_PRIVATE)
		editor = sharedPreferences.edit()
	}

1. 값을 저장하는 코드

binding.checkboxLoginInfo!!.isChecked = 
sharedPreferences.getBoolean(getString(R.string.auto_login).false)
binding.userid!!.setText(sharedPreferences.getString(getString(R.string.auto_login_id),""))
binding.password.setText(sharedPreferences.getString(getString(R.string.auto_login_password),""))

//get 뒤에 key값과 defaultValue 두 가지를 써야하는데
// key 값이 null일 경우 반환할 defaultValue 값을 지정해주는 것이다.

3. 값을 저장하는 코드

if(binding.checkboxSaveLoginInfo!!.isChecked){
	editor.putString(
	getString(R.string.auto_login_id),
	binding.userid!!.text.toString()
	)
	editor.putString(
	getString(R.string.auto_login_password),
	binding.password.text.toString()
	)
	editor.commit()
}else{
	editor.putString(getString(R.string.auto_login_id),"")
	editor.putString(getString(R.string.auto_login_password),"")
	editor.commit()
}