Cannot change whether this adapter has stable IDs while the adapter has registered observers

问题

I am using RecyclerView in my android project and its performance has been really awful. From the answers here, I tried adding adapter.setHasStableIds(true); to my code. When running, I got an error:

java.lang.IllegalStateException: Cannot change whether this adapter has stable IDs while the adapter has registered observers.

My full logCat is as below;

09-22 22:22:23.634 1808-1808/com.revosleap.movielist E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.revosleap.movielist, PID: 1808
java.lang.IllegalStateException: Cannot change whether this adapter has stable IDs while the adapter has registered observers.
    at android.support.v7.widget.RecyclerView$Adapter.setHasStableIds(RecyclerView.java:6749)
    at com.revosleap.movielist.Utils.UrlUtils.GenreFetcher.getGenre(GenreFetcher.java:48)
    at com.revosleap.movielist.MainActivity$2.onItemSelected(MainActivity.java:221)
    at android.widget.AdapterView.fireOnSelected(AdapterView.java:1124)
    at android.widget.AdapterView.access$200(AdapterView.java:54)
    at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:1089)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:145)
    at android.app.ActivityThread.main(ActivityThread.java:5942)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)

How can I fix this please?

回答1:

You must set the adapter's hasStableIds to true BEFORE you assign the adapter to your recyclerview.

YourAdapter adapter = new YourAdapter();
adapter.setHasStableIds(true);
myRecyclerView.setAdapter(adapter);

回答2:

as the recyclerView source code:

    /**
     * Indicates whether each item in the data set can be represented with a unique identifier
     * of type {@link java.lang.Long}.
     *
     * @param hasStableIds Whether items in data set have unique identifiers or not.
     * @see #hasStableIds()
     * @see #getItemId(int)
     */
    public void setHasStableIds(boolean hasStableIds) {
        if (hasObservers()) {
            throw new IllegalStateException("Cannot change whether this adapter has "
                    + "stable IDs while the adapter has registered observers.");
        }
        mHasStableIds = hasStableIds;
    } .

so you can workaround it .

    if (!adapter.hasObservers()) {
        adapter.setHasStableIds(true)
    }

回答3:

You can not use adapter.setHasStableIds(true); with ObservableArrayList/ObservableFields

来源：https://stackoverflow.com/questions/52460141/cannot-change-whether-this-adapter-has-stable-ids-while-the-adapter-has-register

标签

android

performance

android-recyclerview