Need help for accessing system built in contacts in android

I am new to android.I want to use system built in contacts management facility that android provides.I have searched a lot but could开发者_运维问答n't get an exact idea that how to proceed for that.So please help me about how to add contacts from code(and not from GUI),how to access them in my application(simply to show all records in textview). Is it possible to do this without using SQLite or file operations (means just reading and writing in system memory) ???

Thanks in advance...

Have a look at this code!

btn_existing_contacts.setOnClickListener(new OnClickListener() {
        public void onClick(View v){
            Intent intent_contacts = new Intent(Intent.ACTION_PICK,ContactsContract.Contacts.CONTENT_URI);
            /*contacts.setAction(android.content.Intent.ACTION_VIEW);
            contacts.setData(People.CONTENT_URI);*/
            startActivityForResult(intent_contacts, 0);
            //displayContacts();


        }
     });

after returning from contacts screen,

@Override
protected void onActivityResult(int requestCode, int resultCode,Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
String name,mailid,id;
switch(requestCode)
{
case 0:
{
    if(resultCode == RESULT_OK )
    {
        Uri contactdata  = data.getData();

        Cursor cur = managedQuery(contactdata, null, null, null, null);


        if(cur.moveToFirst())
        {
            id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
            Cursor emailCur = getContentResolver().query(ContactsContract.CommonDataKinds.Email.CONTENT_URI,null,
                    ContactsContract.CommonDataKinds.Email.CONTACT_ID + " = ?",new String[]{id}, null); 
            emailCur.moveToFirst();
            String email = emailCur.getString(emailCur.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA));


            name = cur.getString(cur.getColumnIndexOrThrow(ContactsContract.Contacts.DISPLAY_NAME));
            //mailid = cur.getString(cur.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA));
            //mailid = cur.getString(cur.getColumnIndex(ContactsContract.CommonDataKinds.Email._ID));
            //Toast.makeText(context_contact, "Name:"+name+"\nmailid:"+email, Toast.LENGTH_SHORT).show();
            Intent intent_add_invitees = new Intent(<ClassContext>,<ur classname>.class);
            intent_add_invitees.putExtra("invitee_name", name);
            intent_add_invitees.putExtra("invitee_mailid", email);
            setResult(RESULT_OK, intent_add_invitees);
            finish();

        }
    }

}



}
}