ViewModel SavedStateHandler.get for LiveData can't set default value as per the document?

问题

In referring to https://developer.android.com/reference/androidx/lifecycle/SavedStateHandle#getLiveData(java.lang.String,%20T)

The sample codes in Java as below.

 String defaultValue = ...; // nullable
 LiveData<String> liveData;
 if (defaultValue != null) {
     liveData = savedStateHandle.get(KEY, defaultValue);
 } else {
     liveData = savedStateHandle.get(KEY);
 }

However, I notice that when tried to compile the code, the statement below is not compilable.

savedStateHandle.get(KEY, defaultValue);

It error out stating

get(String) in SavedStateHandle cannot be applied to (String, java.lang.String).

I trace into the code, and seems like savedStatehandle doesn't have a get that takes in a default value. Did I miss anything?

回答1:

Apparently the Google Document has typo. It supposed to be

 String defaultValue = ...; // nullable
 LiveData<String> liveData;
 if (defaultValue != null) {
     liveData = savedStateHandle.getLiveData(KEY, defaultValue);
 } else {
     liveData = savedStateHandle.getLiveData(KEY);
 }

i.e. getLiveData instead of just get.

来源：https://stackoverflow.com/questions/61166599/viewmodel-savedstatehandler-get-for-livedata-cant-set-default-value-as-per-the