Custom listview and custom ArrayAdapter

Question

I do not get any error here but i am failing to display anything on the screen i have 2 XML file main.xml has a list view with id @id/android:list and another xml has a relative layout with 3 text views i am trying to display the data from the database but nothing seems to come. I tried the simple list layout and then i was able to display the content of one of the columns in the database. But when i try this for a custom layout nothing is displayed except blank lines.

This is the main activity that starts when the applicaton is launched.

public class Db extends ListActivity {
private SQLiteDatabase newDb;
DataBaseHelper myDbHelper = new DataBaseHelper(this);
public ListAdapter adapter;
private ArrayList<String> results = new ArrayList<String>();


public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

setContentView(R.layout.main);
    openDatabase();
    newDb = myDbHelper.getReadableDatabase();   
    Cursor c = newDb.rawQuery("SELECT _id, organisation, address, postcode FROM shoplist", null);
    int i_organisation = c.getColumnIndex("organisation");
    int i_id = c.getColumnIndex("_id");
    int i_address = c.getColumnIndex("address");
    int i_postcode = c.getColumnIndex("postcode");

    //int count = c.getCount();
    //String data[] = new String[count];
    //int i= 0;
    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext())
    {
        String i1 = c.getString(c.getColumnIndex("_id"));
        String i2 = c.getString(c.getColumnIndex("organisation"));
        String i3 = c.getString(c.getColumnIndex("address"));
        results.add(i1);

        //i++;
    }
    customAdapter adapter = new customAdapter(getApplicationContext(),
            R.layout.main, results, results, results);
    setListAdapter(adapter);





}

private long inserttodata() {
    // TODO Auto-generated method stub
    ContentValues cv = new ContentValues();
    cv.put("id", "112");
    cv.put("organisation","test" );
     return newDb.insert("shoplist", null, cv);
}

private void openDatabase() {

    try {

        myDbHelper.createDataBase();

    } catch (IOException ioe) {

        throw new Error("Unable to create database");

    }

    try {

        myDbHelper.openDataBase();


    } catch (SQLException sqle) {
System.out.println("failed to open");
        throw sqle;

    }
    //String[] columns= new String[]{"_id", "Organisation"};
    //cursor = newDb.query("Shop", columns, null, null, null, null, null);

}

}

My database helper class

public class DataBaseHelper extends SQLiteOpenHelper{

//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/calc.three/databases/";

private static String DB_NAME = "charity.db";

private SQLiteDatabase myDataBase; 

private final Context myContext;


public DataBaseHelper(Context context) {

    super(context, DB_NAME, null, 1);
    this.myContext = context;
}   


public void createDataBase() throws IOException{

    boolean dbExist = checkDataBase();

    if(dbExist){
        //do nothing - database already exist
    }else{

        //By calling this method and empty database will be created into the default system path
           //of your application so we are gonna be able to overwrite that database with our database.
        this.getReadableDatabase();

        try {

            copyDataBase();

        } catch (IOException e) {

            throw new Error("Error copying database");

        }
    }

}

/**
 * Check if the database already exist to avoid re-copying the file each time you open the application.
 * @return true if it exists, false if it doesn't
 */
private boolean checkDataBase(){

    SQLiteDatabase checkDB = null;

    try{
        String myPath = DB_PATH + DB_NAME;
        checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

    }catch(SQLiteException e){

        //database does't exist yet.

    }

    if(checkDB != null){

        checkDB.close();

    }

    return checkDB != null ? true : false;
}

/**
 * Copies your database from your local assets-folder to the just created empty database in the
 * system folder, from where it can be accessed and handled.
 * This is done by transfering bytestream.
 * */
private void copyDataBase() throws IOException{

    //Open your local db as the input stream
    InputStream myInput = myContext.getAssets().open(DB_NAME);

    // Path to the just created empty db
    String outFileName = DB_PATH + DB_NAME;

    //Open the empty db as the output stream
    OutputStream myOutput = new FileOutputStream(outFileName);

    //transfer bytes from the inputfile to the outputfile
    byte[] buffer = new byte[2048];
    int length;
    while ((length = myInput.read(buffer))>0){
        myOutput.write(buffer, 0, length);
    }

    //Close the streams
    myOutput.flush();
    myOutput.close();
    myInput.close();

}

public void openDataBase() throws SQLException{

    //Open the database
    String myPath = DB_PATH + DB_NAME;
    SQLiteDatabase.CursorFactory c = null;
    myDataBase = SQLiteDatabase.openDatabase(myPath, c , SQLiteDatabase.OPEN_READWRITE);

}

@Override
public synchronized void close() {

        if(myDataBase != null)
            myDataBase.close();

        super.close();

}

@Override
public void onCreate(SQLiteDatabase db) {

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}}

My custom adapter class

 public class customAdapter extends ArrayAdapter<String> {
static List<String> serialNo = new ArrayList<String>();
static List<String> name = new ArrayList<String>();  
static List<String> address = new ArrayList<String>();

Context myContext;

public customAdapter(Context context, int resource, List<String> c_serialNo,
    List<String> c_name, List<String> c_address) {

super(context, resource, c_serialNo);

myContext = context;
serialNo = c_serialNo;
name = c_name;
address = c_address;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
    LayoutInflater vi = (LayoutInflater) myContext
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    v = vi.inflate(R.layout.main, null);
}

TextView tv_serialNo = (TextView) v.findViewById(R.id.serialNo);
TextView tv_name = (TextView) v.findViewById(R.id.name);
TextView tv_address = (TextView) v.findViewById(R.id.address);

if (tv_serialNo != null) {
    tv_serialNo.setText(serialNo.get(position));
}
if (tv_name != null) {
    tv_name.setText(name.get(position));
}
if (tv_address!= null) {
    tv_address.setText(address.get(position));
}

return v; }}

The main.xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">

   <ListView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@id/android:list"></ListView>


</LinearLayout>

The custom_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">



        <RelativeLayout android:layout_width="fill_parent" android:layout_height="80dp" >
            <TextView android:id="@+id/serialNo"
                android:layout_height="38dp"
                android:layout_width="40dp"
                android:padding="1dip"
                android:gravity="top"                    
                android:text="sn"
                                    />
            <TextView android:id="@+id/name"
                android:layout_height="38dp"
                android:layout_width="240dp"
                android:padding="1dip"
                android:gravity="top"                    
                android:text="name"
                android:layout_toRightOf="@id/serialNo"
                                    />

            <ImageButton
                android:id="@+id/fav"
                android:layout_width="38dp"
                android:layout_height="38dp"
                android:layout_alignParentTop="true"
                android:layout_toRightOf="@+id/name"
                android:src="@drawable/ic_launcher" />
            <TextView android:id="@+id/address"
                android:layout_height="40dp"
                android:layout_width="300dp"
                android:padding="1dip"

                android:text="name"
                android:layout_below="@id/serialNo"
                                    />

            <ImageView
                android:id="@+id/source"
                android:layout_width="40dp"
                android:layout_height="40dp"
                android:layout_alignBottom="@+id/address"
                android:layout_toRightOf="@+id/address"
                android:src="@drawable/pg" />

        </RelativeLayout>


</LinearLayout> 

Answer 1

Several things I see... R.layout main is your main layout and you are trying to set it as the row layout for your adapter. The two should be different.

Second, unless you have some reason that's not obvious, you are doing a lot of extra work creating arrays...

Third, it looks like you are trying to list things that are not pulled from your cursor or in any other array you've shown (serialNo).

It would be much simpler to use a SimpleCursorAdapter like so:

openDatabase();  
newDb = myDbHelper.getReadableDatabase();    
Cursor c = newDb.rawQuery("SELECT _id, organisation, address, postcode FROM shoplist", null);  

// let the system manage your cursor
getActivity().startManagingCursor(c);      

//  tell the adapter what columns to pull data from
String[] from = new String[] { "_id", "organisation", "address" };      

// tell the adapter what resource ids in your row layout to map the data to     
int[] to = new int[] { R.id.serialNo, R.id.name, R.id.address };      

// create the adapter, specifying the context, the xml file to use for the row layout, the cursor to pull the data from, and the map of where to put the data in the form of from and to arrays 
SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(this, R.layout.your_row_xml, c, from, to);

// set the adapter to your list
setListAdapter(mAdapter);

Answer 2

Solved: I was inflating the wrong XMl file. inflate custom_list.xml and it starts displaying.