Question

I am relatively new to Android programming. So please, forgive me for writing or asking anything stupid. I am working on an Android application in which I am using SQLite database to store data. I need to access this database from more Activities and after some research I have concluded that the best way to do so is using an Application class. But this is where my program stops working.

I have my Application class:

import android.app.Application;

public class MyApplication extends Application {
    public CONTACT_DB = new CONTACT_DB(this);
}

where CONTACT_DB class is where I have defined my database and has this constructor:

private final Context context;
private DatabaseHelper DBHelper;

public CONTACT_DB(Context ctx) {
    this.context = ctx;
    DBHelper = new DatabaseHelper(context);
}

Now in my Activity, where I need to access this database

public class Add_contact extends Activity {
    CONTACT_DB db;

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

        MyApplication appState = ((MyApplication)getApplicationContext());
        db = appState.db;
    }
}

My program works fine, but when it gets to line
MyApplication appState = ((MyApplication)getApplicationContext());
then it crashes. I tried to use just a simple int instead of my CONTACT_DB class and it still srashes. Any ideas?

Answer 1

Have you declared your custom application class in the manifest?

For example:

<application
    android:name="com.yournamespace.appname.MyApplication"
    android:icon="@drawable/icon"
    android:label="@string/app_name">