i see a weird bug here.. i have a list view which is populated from the server in an async… it populates first and then displays the list view… but when i scroll down it crashes… from the logs i see it is not related to population of list view and all.. … can you please help me?
04-12 12:39:54.676: E/AndroidRuntime(1984): FATAL EXCEPTION: main
04-12 12:39:54.676: E/AndroidRuntime(1984): java.lang.NullPointerException
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.AbsListView.obtainView(AbsListView.java:1304)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.ListView.makeAndAddView(ListView.java:1727)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.ListView.fillUp(ListView.java:682)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.ListView.correctTooHigh(ListView.java:1349)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.ListView.fillGap(ListView.java:624)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.AbsListView.trackMotionScroll(AbsListView.java:2944)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.AbsListView.onTouchEvent(AbsListView.java:2065)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.widget.ListView.onTouchEvent(ListView.java:3315)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.View.dispatchTouchEvent(View.java:3766)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:897)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
04-12 12:39:54.676: E/AndroidRuntime(1984): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1671)
04-12 12:39:54.676: E/AndroidRuntime(1984): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.app.Activity.dispatchTouchEvent(Activity.java:2086)
04-12 12:39:54.676: E/AndroidRuntime(1984): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1655)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.view.ViewRoot.handleMessage(ViewRoot.java:1785)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.os.Handler.dispatchMessage(Handler.java:99)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.os.Looper.loop(Looper.java:123)
04-12 12:39:54.676: E/AndroidRuntime(1984): at android.app.ActivityThread.main(ActivityThread.java:4627)
04-12 12:39:54.676: E/AndroidRuntime(1984): at java.lang.reflect.Method.invokeNative(Native Method)
04-12 12:39:54.676: E/AndroidRuntime(1984): at java.lang.reflect.Method.invoke(Method.java:521)
04-12 12:39:54.676: E/AndroidRuntime(1984): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
04-12 12:39:54.676: E/AndroidRuntime(1984): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)
04-12 12:39:54.676: E/AndroidRuntime(1984): at dalvik.system.NativeStart.main(Native Method)
this is the custom adapter class which extends Base Adapter
@Override
public int getCount() {
return mAppIconMapList.size();
}
@Override
public Object getItem(int position) {
return mAppIconMapList.get(position);
}
public Object getAppName(int position) {
return mAvaiableApps.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// sets the view onto list view
LinearLayout rowLayout = null;
System.out.println("getView " + position + " " + convertView);
if (convertView == null) {
// inflating the row
rowLayout = (LinearLayout) mInflater.inflate(
R.layout.list_custom_row, parent, false);
mAppIcon = (ImageView) rowLayout.findViewById(R.id.icon);
mAppName = (TextView) rowLayout.findViewById(R.id.application);
mAppName.setTextColor(Color.WHITE);
mAppHint = (TextView) rowLayout.findViewById(R.id.hint);
mAppHint.setTextColor(Color.WHITE);
mDownloadButton = (Button) rowLayout.findViewById(R.id.download);
mDownloadButton.setFocusable(false);
}
// else
// convertView.getTag();
mIcon = mAppIconMapList.get(position);
System.out.println("Icon " + mIcon);
mCurrentApplication = mAvaiableApps.get(position);
System.out.println("Current App " + mCurrentApplication);
mAppIcon.setImageBitmap(mIcon.get(mCurrentApplication));
mAppName.setText(mCurrentApplication.replace(".apk", ""));
mAppHint.setText("Click here to view Description");
return rowLayout;
}
And this is how i am calling
mCustomAdapter = new BWCustomAdapter(mCategory, avaiableApps,
appIconMap, BWListApplication.this);
setListAdapter(mCustomAdapter);
and this is my list view
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="450dip"
android:layout_height="300dip"
android:orientation="vertical" >
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:fadingEdge="none"
android:listSelector="@drawable/list_selector" />
</LinearLayout>
You should really use the ViewHolder pattern. But that is not reason you see a null pointer.
You need to assign a value to
rowLayoutat all times.