Databases
StackOverflow2013
Postsdbo
POListView very slow when scrolling (using ViewHolder/recycling)
Body
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POListView very slow when scrolling (using ViewHolder/recycling)
    text
    copied!<p><strong>UPDATE 2011-08-29</strong> If I remove the image in the NodePickup, the lagginess is gone. </p> <p>The question is - why?</p> <p><strong>----</strong></p> <p>I'm back at trying out some Android dev again. I have an "old" HTC Hero phone lying around, so I booted that one up, did some updates and are now up n running again with Eclipse and the rest.</p> <p>I have Android 2.1 running on the device.</p> <p>I have made a very simple test app that doesnt do anything at all except for showing some Activities and such. Even though there is no database connection, no data fetched from any network the app is very slow. VERY slow.</p> <p>For example, I have a ListView with some custom layout items. When adding only 6-7 items (so that I get the scrolling) it is insanely slow when scrolling. Also, I have some buttons that changes the Activity and also that is very very slow:</p> <pre><code>mButtonListenerUPP = new OnClickListener() { @Override public void onClick(View v) { Intent myIntent = new Intent(BaseActivity.this, ActivityMain.class); BaseActivity.this.startActivity(myIntent); } }; </code></pre> <p>I cannot figure out why, so Im just posting the code here and hope that someone has some tip for me =)</p> <p>Thx!</p> <p><em>The Adapter, NodeRowAdapter</em></p> <pre><code>import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.content.Context; import android.view.*; import android.widget.ArrayAdapter; import android.widget.TextView; public class NodeRowAdapter extends ArrayAdapter { private Activity context; private ArrayList&lt;Node&gt; mList; private LayoutInflater inflater; NodeRowAdapter(Activity context, ArrayList&lt;Node&gt; objects) { super(context, R.layout.nodepickup, objects); this.context=context; mList = objects; inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); } class ViewHolder { TextView name; TextView time; TextView road; Node node; } public Node getNode(int position) { if (mList != null &amp;&amp; mList.size() &gt; position) return mList.get(position); else return null; } public View getView(int position, View convertView, ViewGroup parent) { View view = convertView; ViewHolder holder; if (view == null) { view = inflater.inflate(R.layout.nodepickup, parent, false); holder = new ViewHolder(); holder.name =(TextView)view.findViewById(R.id.name); holder.time =(TextView)view.findViewById(R.id.time); holder.road =(TextView)view.findViewById(R.id.road); view.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } Node node = mList.get(position); holder.name.setText(node.name); holder.time.setText(node.time); holder.road.setText(node.road); return(view); } } </code></pre> <p><em>The main activity, ActivityMain</em></p> <pre><code>public class ActivityMain extends BaseActivity { private NodeRowAdapter _nodeRowAdapter; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { requestWindowFeature(Window.FEATURE_NO_TITLE); super.onCreate(savedInstanceState); setContentView(R.layout.main); SICApplication._myContext = this; SICApplication._myContext = this; _nodeRowAdapter = new NodeRowAdapter(this, SICApplication.dataHolder_activityMain._nodes); ListView listView1 = (ListView) findViewById(R.id.ListViewNodes); listView1.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView&lt;?&gt; parent, View view, int position, long id) { Node node = _nodeRowAdapter.getNode(position); Log.v("MyApp", "Node=" + node.name); } }); listView1.setAdapter(_nodeRowAdapter); } /* Handles item selections */ public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.add_item: addNodeItem(); return true; } return false; } private void addNodeItem() { _nodeRowAdapter.add(new Node("Test", "asd asd ", "14:00", 1)); } } </code></pre> <p><em>The custom list item, NodePickup</em></p> <pre><code>public class NodePickup extends LinearLayout { public NodePickup(Context context, AttributeSet attributeSet) { super(context, attributeSet); LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); inflater.inflate(R.layout.nodepickup, this); this.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { AlertDialog.Builder builder = new AlertDialog.Builder(getContext()); builder.setMessage("Ajabaja!") .setCancelable(true) .setPositiveButton("JA!", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { dialog.cancel(); } }); builder.show(); } }); } } </code></pre> <p><em>And lastly, the NodePickup XML layout</em></p> <pre><code>&lt;LinearLayout android:id="@+id/LinearLayout01" android:layout_width="fill_parent" android:layout_height="64dip" android:orientation="horizontal" android:background="@drawable/stateful_background" xmlns:android="http://schemas.android.com/apk/res/android"&gt; &lt;ImageView android:id="@+id/ImageView01" android:layout_width="40dip" android:layout_height="40dip" android:src="@drawable/arrow_up_green" android:background="@android:color/transparent"&gt; &lt;/ImageView&gt; &lt;LinearLayout android:id="@+id/LinearLayout02" android:background="@android:color/transparent" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android"&gt; &lt;TextView android:text="14:46 (15 min)" android:id="@+id/time" android:textSize="12dip" android:textColor = "#000000" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@android:color/transparent"&gt; &lt;/TextView&gt; &lt;TextView android:text="test" android:id="@+id/road" android:textSize="12dip" android:textColor = "#000000" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@android:color/transparent"&gt; &lt;/TextView&gt; &lt;TextView android:text="test test" android:id="@+id/name" android:textSize="12dip" android:textColor = "#000000" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@android:color/transparent"&gt; &lt;/TextView&gt; &lt;/LinearLayout&gt; &lt;/LinearLayout&gt; </code></pre>
 

Querying!

 
Guidance
An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload