Reputation:

Why does my runOnUiThread not work

Why does this not work in my aSyncTask? My app crashes. I'm trying to update my list from a mysql table

protected void onPostExecute(String result){
            // dismiss dialog
            pDialog.dismiss();      
            runOnUiThread(new Runnable(){
                public void run(){
                    // Add adapter to the list
                    MenuAdapter adapter = new MenuAdapter(Albums.this, itemList);
                    ListView list = (ListView)findViewById(R.id.list);
                    adapter.notifyDataSetChanged();
                    list.setAdapter(adapter);   
                    }
                });

        }

LogCat:

02-28 18:21:09.013: E/AndroidRuntime(10600): FATAL EXCEPTION: main
02-28 18:21:09.013: E/AndroidRuntime(10600): java.lang.NullPointerException
02-28 18:21:09.013: E/AndroidRuntime(10600):    at com.example.whs.Albums$LoadAllItems.onPostExecute(Albums.java:149)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at com.example.whs.Albums$LoadAllItems.onPostExecute(Albums.java:1)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at android.os.AsyncTask.finish(AsyncTask.java:631)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at android.os.AsyncTask.access$600(AsyncTask.java:177)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at android.os.Handler.dispatchMessage(Handler.java:99)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at android.os.Looper.loop(Looper.java:137)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at android.app.ActivityThread.main(ActivityThread.java:4898)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at java.lang.reflect.Method.invokeNative(Native Method)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at java.lang.reflect.Method.invoke(Method.java:511)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
02-28 18:21:09.013: E/AndroidRuntime(10600):    at dalvik.system.NativeStart.main(Native Method)

this is where i make the itemList from the mysql table.

items = json.getJSONArray(TAG_ITEMS);

                    // loop through the items
                    for (int i = 0; items.length() > i; i++){
                        // Get the item in variable c
                        JSONObject c = items.getJSONObject(i);

                        // Store in a variable
                        String id = c.getString(TAG_ID);
                        String name = c.getString(TAG_NAME);
                        String username = c.getString(TAG_USERNAME);
                        if(username == ""){
                            username = "onbekend";
                        }

                        // Create the HashMap
                        HashMap<String, String> map = new HashMap<String, String>();

                        // add it
                        map.put(TAG_ID, id);
                        map.put(TAG_USERNAME, username);
                        map.put(TAG_NAME, name);
                        map.put(THUMBNAIL, "updates");

                        // to arraylist
                        itemList.add(map);                      
                    }

What id should i use for the listview, i have "@android:id/list"

edit: Here is the latest log after using Albums.this.getListView();

02-28 18:35:10.718: E/AndroidRuntime(23103): FATAL EXCEPTION: main
02-28 18:35:10.718: E/AndroidRuntime(23103): java.lang.ArrayIndexOutOfBoundsException: length=2; index=2
02-28 18:35:10.718: E/AndroidRuntime(23103):    at com.example.whs.MenuAdapter.getView(MenuAdapter.java:58)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.AbsListView.obtainView(AbsListView.java:2461)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.ListView.makeAndAddView(ListView.java:1775)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.ListView.fillDown(ListView.java:678)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.ListView.fillFromTop(ListView.java:739)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.ListView.layoutChildren(ListView.java:1628)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.AbsListView.onLayout(AbsListView.java:2296)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1655)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1513)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1426)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1655)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1513)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1426)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1655)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1644)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1428)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1655)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1513)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1426)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.View.layout(View.java:14055)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewGroup.layout(ViewGroup.java:4604)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2000)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1821)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1118)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4550)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.Choreographer.doCallbacks(Choreographer.java:555)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.Choreographer.doFrame(Choreographer.java:525)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.os.Handler.handleCallback(Handler.java:615)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.os.Handler.dispatchMessage(Handler.java:92)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.os.Looper.loop(Looper.java:137)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at android.app.ActivityThread.main(ActivityThread.java:4898)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at java.lang.reflect.Method.invokeNative(Native Method)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at java.lang.reflect.Method.invoke(Method.java:511)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
02-28 18:35:10.718: E/AndroidRuntime(23103):    at dalvik.system.NativeStart.main(Native Method)

Upvotes: 0

Answers (3)

Sam

Reputation: 86948

What id should i use for the listview, i have "@android:id/list"

You need to use findViewById(android.R.id.list), since it is in the Android namespace unlike a regular id "@id/list" where you simply use findViewById(R.id.list).

Addition This new error is probably in your MenuAdapter's getCount() method but I know it crashes in getView()... How do I know? Let's walk through the LogCat:

java.lang.ArrayIndexOutOfBoundsException: length=2; index=2
    at com.example.whs.MenuAdapter.getView(MenuAdapter.java:58)
    at android.widget.AbsListView.obtainView(AbsListView.java:2461)
    at android.widget.ListView.makeAndAddView(ListView.java:1775)

The line on top is the exception, you are trying to read a value that doesn't exist in an Array. The next line shows the last place your code ran and where the error was thrown. MenuAdapter.java:58 is the file name and line number, for a bonus it tells you the method name too: getView(). The only Array used in a typical Adapter is the one you passed to the constructor...

Upvotes: 1

ρяσѕρєя K

Reputation: 132982

Because onPostExecute is always invoked on the UI Thread, there is no need to use runOnUiThread for accessing or updating UI elements in onPostExecute. Change your code as:

protected void onPostExecute(String result){
            // dismiss dialog
            pDialog.dismiss();      

            // access or update UI here without runOnUiThread

        }

Upvotes: 4

burmat

Reputation: 2548

Isn't runOnUiThread() redundant? onPostExecute() is already running on the UI thread, you should not need it. Try taking it out and see what happens!

Source: http://developer.android.com/reference/android/os/AsyncTask.html

Upvotes: 0

Why does my runOnUiThread not work

Answers (3)

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