Android SavedStateHandle doesn't save in ViewModel

问题

I have a ViewModel which takes a SavedStateHandle parameter. I am saving a String in there like this:

    private fun saveString(str: String) {
        state.set(KEY_STRING, str)
    }

Then I force-close my app and relaunch it, and want to retrieve the saved string like this:

fun getSavedString(): String? {
        return state.get<String>(KEY_String)
    }

However, it always returns null. Any ideas how to use SavedStateHandle correctly?

来源：https://stackoverflow.com/questions/62139420/android-savedstatehandle-doesnt-save-in-viewmodel