Question

I have this code:

ListView listView;
static final String[] Liste = {"Satz des Pythagoras", "abc-Formel", "pq-Formel"};

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    setTitle("CalcPlus");
    listView = getListView();
    //Own row layout
    listView.setAdapter(new ArrayAdapter<String>(this,
                R.layout.activity_home, Liste));
    listView.setOnItemClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_home, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.maths:
            return true;
        case R.id.physics:
            Intent myIntent2 = new Intent(Home.this, ActivityPhysics.class);
            startActivity(myIntent2);
        default:
            return super.onOptionsItemSelected(item);
    }
}
public void onItemClick(AdapterView<?> adapter, View view,
            int position, long id) {
    if ("Satz des Pythagoras".equals(Liste[position])) {
        Intent sdp = new Intent(view.getContext(), MainActivity.class);
        startActivityForResult(sdp, 0);
    }
    else if ("abc-Formel".equals(Liste[position])) {
        Intent abc = new Intent(view.getContext(), ActivityABC.class);
        startActivityForResult(abc, 0);
    }
    else if ("pq-Formel".equals(Liste[position])) {
        Intent pq = new Intent(view.getContext(), ActivityPQ.class);
        startActivityForResult(pq, 0);
    }
}

This should display a list and a actionbar.
It did, for some time.

It looks like I messed up the code and, since I’m not having that much experience, can’t find my mistake…so could someone review my code? 🙂

Because now it loads the activity..but doesn’t display the list or the actionbar 😮

Here is the XML in \menu\activity_home.xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@+id/menu_settings"
    android:orderInCategory="100"
    android:showAsAction="never" />
<item android:id="@+id/maths"
    android:title="@string/maths"
    android:orderInCategory="1"
    android:showAsAction="always|withText" 
    android:titleCondensed="@string/maths" 
    android:icon="@drawable/ic_action_calculator" /> 
<item android:id="@+id/physics"
    android:icon="@drawable/ic_action_line_chart"
    android:title="@string/physics"
    android:orderInCategory="2"
    android:showAsAction="always|withText"/>

This is layout\activity_home.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/hello_world"/>

</RelativeLayout>

So basically it’s empty.

Answer 1

With these two lines:

setContentView(R.layout.activity_home);
...
listView.setAdapter(new ArrayAdapter<String>(this,
            R.layout.activity_home, Liste));

You are using the same layout for the entire Activity and each row, which doesn’t make sense. The Activity’s layout should contain a ListView and the row layout shouldn’t…

---

To use the default layouts, remove this line:

setContentView(R.layout.activity_home);

and change this one:

listView.setAdapter(new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, Liste));

---

Also you need to onListItemClick() not onItemClick() to have the row clicks work.

@Override
protected void onListItemClick (ListView l, View v, int position, long id) {...}

---

Okay now the only entry in LogCat is Array Adapter:”You musst supply a resource ID for a textview.

You must give your TextView an id:

<TextView
    android:id="@+id/text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/hello_world"/>

And change the way you create your adapter to:

listView.setAdapter(new ArrayAdapter<String>(this,
            R.layout.activity_home, R.id.text, Liste));