Question

I am crashing trying to launch a sub-activity. I have a small app to demonstrate the problem. The main part of the app is a list view, and when you click on an item in the list view it is supposed to launch an activity which brings up a gallery view. The app crashes before onCreate() is called for the gallery view class, so I suspect I have omitted some necessary thing in the xml for the activity description.

manifest:

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="randombrand.ListGallery"
          android:versionCode="1"
          android:versionName="1.0">
        <uses-sdk android:minSdkVersion="7" />

        <application android:icon="@drawable/icon" android:label="@string/app_name">
            <activity android:label="@string/app_name" android:name=".ListGallery">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>

            <activity android:label="Manual Top" android:name=".TestGallery">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.DEFAULT" />
                </intent-filter>
            </activity>

        </application>
    </manifest>

java:

    public class ListGallery extends ListActivity
    {
        private static final String[] astrMainMenu = { "List Item 1", "List Item 2" };


        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);

            setListAdapter(new ArrayAdapter<String>(this, R.layout.main,
                    astrMainMenu));

            ListView lView = getListView();
            lView.setTextFilterEnabled(true);
        }

        @Override
        protected void onListItemClick(ListView l, View v, int position, long id)
        {
            Intent intent = new Intent();

            intent.setClass(this, TestGallery.class);

            startActivity(intent);
        }
    }

stack trace for crash when I call startActivity():

ActivityThread.performLaunchActivity(ActivityThread$ActivityRecord, Intent) line: 2417  
ActivityThread.handleLaunchActivity(ActivityThread$ActivityRecord, Intent) line: 2512   
ActivityThread.access$2200(ActivityThread, ActivityThread$ActivityRecord, Intent) line: 119 
ActivityThread$H.handleMessage(Message) line: 1863  
ActivityThread$H(Handler).dispatchMessage(Message) line: 99 
Looper.loop() line: 123 
ActivityThread.main(String[]) line: 4363    
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]  
Method.invoke(Object, Object...) line: 521  
ZygoteInit$MethodAndArgsCaller.run() line: 860  
ZygoteInit.main(String[]) line: 618 
NativeStart.main(String[]) line: not available [native method]  

thanks in advance,

Jay

Answer 1

You should create Intent using next code:

Intent intent = new Intent(this, TestGallery.class);

Its not enough to just specify class name, your also need to specify package name where this class is located. In the above code example package name is taken from this (this is Context, and package name is taken via Context.getPackageName()).

P.S. Note that under “package” I do not mean java’s package, I mean Android’s package. The one that is specified in AndroidManifest.xml file.