RecyclerView Update

Question

I have a recycler view that i want to update it.It likes Instagram Posts that gets post datas from a Server and add it to Array list and update Adapter with notifyDataSetChanged() function.but when it want to update gets this error.

android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
    at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:7905)
    at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:1276)
    at android.view.View.requestLayout(View.java:22139)
    at android.view.View.requestLayout(View.java:22139)
    at android.view.View.requestLayout(View.java:22139)
    at android.view.View.requestLayout(View.java:22139)
    at android.view.View.requestLayout(View.java:22139)
    at android.view.View.requestLayout(View.java:22139)
    at android.view.View.requestLayout(View.java:22139)
    at android.support.v7.widget.RecyclerView.requestLayout(RecyclerView.java:3970)
    at android.support.v7.widget.RecyclerView$RecyclerViewDataObserver.onChanged(RecyclerView.java:5060)
    at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyChanged(RecyclerView.java:11540)
    at android.support.v7.widget.RecyclerView$Adapter.notifyDataSetChanged(RecyclerView.java:6762)
    at com.example.MainActivity$2.run(MainActivity.java:179)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:257)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
    at java.lang.Thread.run(Thread.java:784)

This is my code

AsyncTask.execute(new Runnable() {
        @Override
        public void run() {
            while (true) {
                String name = getHtml.getUrlContent("URL" + something);
                something += 1;
                list.add(new Model(Model.IMAGE_TYPE, name));
                adapter.notifyDataSetChanged();
            }
        }
    });

I thought that errors occurred because of AsyncTask and then i changed it to runOnUiThread() function but this method first gets all data and then create View and because of that app gets too long to start. What can i do?

Answer 1

Your approach is not the greatest, may have many issues but you can use

runOnUiThread(new Runnable() {
     void run() {
           adapter.notifyDataSetChanged();
     }
});

Other solution would be make a class Extend it from AsyncTask, override doInBackground and on post execute method. Fetch data on doInBackground() and update ui onPostExecute()

Guide: https://developer.android.com/reference/android/os/AsyncTask