Question

I have written an android application to display a list. Code has taken from an example. There is no error in compiling, but nothing is displayed on after running the application. Expecting you help to solve this problem thanks. Please find below code i used…

Main Activity

public class MainActivity extends ListActivity {
  ArrayList<String> listItems=new ArrayList<String>();
  ArrayAdapter<String> adapter;
  int clickCounter=0;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    listItems.add("Hello");

    adapter=new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, listItems);
    setListAdapter(adapter);
  }

  public void addItems(View v) {
    listItems.add("Clicked : "+clickCounter++);
    adapter.notifyDataSetChanged();
  }
}

mainactivity.xml

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<Button
    android:id="@+id/addBtn"
    android:text="Add New Item"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:onClick="addItems"/>
<ListView
    android:id="@android:id/list"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:drawSelectorOnTop="false"
/>

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.testlistview"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="15" />

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/title_activity_main" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="android.app.ListActivity" />
    </activity>
</application>
</manifest>

Answer 1

Please add the following intentfilter to the manifest:

        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>

Android needs this intent filter to know which activity to start.