Using methods of classes in android programming

Question

Hi everyone I am a beginner in android, please help. I have DBAdapter class which has different methods to manipulate my db. I want to call the method i.e. insert when button is clicked. However it only works outside of listener (View.OnClickListener).

    package com.dbclass;

    import android.app.Activity;
    import android.database.Cursor;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.Button;
    import android.widget.Toast;

    public class DBActivity extends Activity {
        /** Called when the activity is first created. */
       @Override
       public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button btn1 = (Button)findViewById(R.id.Button01);
        btn1.setOnClickListener(btn1Listener);


        DBAdapter db = new DBAdapter(this);        
        db.open();  

        long id;
         // this needs to go to setOnclick method
        id = db.insertTitle(
                "0470285818",
                "Alanel",
                "Wrox");        

        Cursor c = db.getAllTitles();
        if (c.moveToFirst())
        {
            do {          
                DisplayTitle(c);
            } while (c.moveToNext());
        }
        db.close();
    }

    public void DisplayTitle(Cursor c)
    {
        Toast.makeText(this, 
                "id: " + c.getString(0) + "\n" +
                "ISBN: " + c.getString(1) + "\n" +
                "TITLE: " + c.getString(2) + "\n" +
                "PUBLISHER:  " + c.getString(3),
                Toast.LENGTH_LONG).show();        
    }
    private View.OnClickListener btn1Listener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
                 // db.insertTitle("0470285818", "Alanel", "Wrox");  

        }
    };
}

Robby Pond · Accepted Answer · 2011-03-18 14:08:13Z

2

Make your db variable a field of the DBActivity. You probably don't want to do db operations on the UI thread though.

answered Mar 18, 2011 at 14:08

Robby Pond

73.5k16 gold badges128 silver badges119 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Matt · Accepted Answer · 2011-03-18 14:10:00Z

2

It looks like you are closing db at the end of your onCreate() method. You should make sure to open() and close() it again in your onClick(). You should also probably do the actual work in a background thread that you start from you onClick() method.

answered Mar 18, 2011 at 14:10

Matt

2,1991 gold badge16 silver badges20 bronze badges

Comments

Will Tate · Accepted Answer · 2011-03-18 14:08:31Z

0

The scope of db is only within your onCreate() method. You may want to make it a public member of your Class.

answered Mar 18, 2011 at 14:08

Will Tate

33.5k9 gold badges80 silver badges71 bronze badges

Collectives™ on Stack Overflow

Using methods of classes in android programming

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related