Question

I have a class that is supposed to call another activity depending on which button has been clicked. This is done by checking the available IDs.

My problem is: The view that is passed to my class has no id, or rather, its value is NO_ID. What puzzles me is that the view, which is a button, does have an ID.

public class StrengthOrganizer extends Activity {

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

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_strength_organizer, menu);
    return true;
}


public void notifyActivity(View view) {
    Intent intent = null;

    int id = view.getId();

    switch(id){
        case    R.id.button_log_book_launcher:
                intent = new Intent(this, LogBook.class);
                break;

        case    R.id.button_programming_launcher:
                intent = new Intent(this, Programming.class);
                break;

        case    R.id.button_visualizer_launcher:
                intent = new Intent(this, Visualizer.class);
                break;

        default:
                return;
    }

    startActivity(intent);
}
}

The corresponding XML file looks like this:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:orientation="vertical" >

<Button android:name="@+id/button_log_book_launcher"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_gravity="center"
        android:text="@string/button_log_book_launcher"
        android:onClick="notifyActivity" />

<Button android:name="@+id/button_programming_launcher"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_gravity="center"
        android:text="@string/button_programming_launcher"
        android:onClick="notifyActivity" />

<Button android:name="@+id/button_visualizer_launcher"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_gravity="center"
        android:text="@string/button_visualizer_launcher"
        android:onClick="notifyActivity" />

</LinearLayout>

Why does the view object have no ID if it’s been give in the XML file?

Answer 1

You used android:name instead of android:id in your XML to assign the ids. Use the latter instead.