Android Kotlin - Saving Preferences (key value pair)

I am trying various simple Android Kotlin examples, to save some persistent data in my app. To start, I am using a straight forward example of writing one key-value pair, and reading it back. here's my code, in my activity's OnCreate()

val sharedPrefFile = "MyPrefFile"
val sharedPreferences: SharedPreferences = this.getSharedPreferences(sharedPrefFile, Context.MODE_PRIVATE)
fun setPref()
{
    val editor = sharedPreferences.edit()
    val myName = "Elvis"
    editor.putString("nameFirst_key", myName)
}
fun getPref()
{
    val myName = sharedPreferences.getString("nameFirst_key", "no_name")
 }
getPref()
setPref()
getPref()

I would expect the first getPref() call to read "no_name", which it does. However, I was hoping the second getPref() call would read "Elvis", but it doesn't - it reads "no_name".

Can anyone tell me what I am doing wrong please?

Thanks

Garrett

CodePudding user response：

You are not calling commit() or apply() on editor, so the edits are not taking effect. This is covered in the documentation.

So, setPref() should be:

fun setPref()
{
    val editor = sharedPreferences.edit()
    val myName = "Elvis"
    editor.putString("nameFirst_key", myName).apply()
}