避免重复收件箱的Listview项目

Question

I am developing a messaging application with inbox activity and conversation activity.For that I am using SQL database to save all received and sent messages and appending them to the listview of inbox activity. I am getting data from database to append. I don't want to append all messages with same number but with the latest one because other messages are going to the conversation. Help me with this. I've searched it but couldn't find it here and one more thing, I am just a learner. Any inputs will be appreciated!

I want this

and Code for inbox activity is

public class ReceiveSMSActivity extends Activity {
DBAdapter myDb;
private List<Message> MyMessages = new ArrayList<Message>();

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

    getResultsAndAppend();
    populateListView();
}

private void getResultsAndAppend() {

    Cursor cursor = myDb.getAllRows();
    if (cursor.moveToFirst()) {
        do {
            // Process the data:
            // String name = cursor.getString(DBAdapter.COL_NAME);
            String number = cursor.getString(DBAdapter.COL_NUMBER);
            String message = cursor.getString(DBAdapter.COL_MESSAGE);

            MyMessages.add(new Message(message, number, true));

        } while (cursor.moveToNext());
    }

}

private void populateListView() {

    ArrayAdapter<Message> adapter = new MyListAdapter();
    ListView list = (ListView) findViewById(R.id.listViewInbox);
    list.setAdapter(adapter);
}

private class MyListAdapter extends ArrayAdapter<Message> {
    public MyListAdapter() {
        super(ReceiveSMSActivity.this, R.layout.inbox_list_item_layout,
                MyMessages);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // Make sure we have a view to work with (may have been given null)
        View itemView = convertView;
        if (itemView == null) {
            itemView = getLayoutInflater().inflate(
                    R.layout.inbox_list_item_layout, parent, false);
        }

        // Find the Message to work with.
        Message currentMessage = MyMessages.get(position);

        // Message:
        TextView message = (TextView) itemView.findViewById(R.id.tvMessage);
        message.setText(currentMessage.getMessage());

        // Number:
        TextView number = (TextView) itemView.findViewById(R.id.tvNumber);
        number.setText(currentMessage.getNumber());

        return itemView;
    }

}


@Override
protected void onDestroy() {
    super.onDestroy();
    closeDB();
}

private void openDB() {
    myDb = new DBAdapter(this);
    myDb.open();

}

private void closeDB() {
    myDb.close();
}

}

and DBAdapter() is

public class DBAdapter {


private static final String TAG = "DBAdapter";

// DB Fields
public static final String KEY_ROWID = "_id";
public static final int COL_ROWID = 0;


public static final String KEY_NAME = "name";
public static final String KEY_NUMBER = "number";
public static final String KEY_MESSAGE = "message";
public static final String KEY_ISSELF= "self";


public static final int COL_NAME = 1;
public static final int COL_NUMBER = 2;
public static final int COL_MESSAGE = 3;
public static final int COL_ISSELF = 4;


public static final String[] ALL_KEYS = new String[] {KEY_ROWID, KEY_NAME, KEY_NUMBER, KEY_MESSAGE, KEY_ISSELF};


public static final String DATABASE_NAME = "MyDb";
public static final String DATABASE_TABLE = "mainTable";

public static final int DATABASE_VERSION = 1;   

private static final String DATABASE_CREATE_SQL = 
        "create table " + DATABASE_TABLE 
        + " (" + KEY_ROWID + " integer primary key autoincrement, "


        + KEY_NAME + " text not null, "
        + KEY_NUMBER + " string not null, "
        + KEY_MESSAGE + " string not null,"
        + KEY_ISSELF + " string not null"
        + ");";


private final Context context;

private DatabaseHelper myDBHelper;
private SQLiteDatabase db;



public DBAdapter(Context ctx) {
    this.context = ctx;
    myDBHelper = new DatabaseHelper(context);
}

// Open the database connection.
public DBAdapter open() {
    db = myDBHelper.getWritableDatabase();
    return this;
}

// Close the database connection.
public void close() {
    myDBHelper.close();
}

// Add a new set of values to the database.
public long insertRow(String name, String number, String message, String isself) {

    // Create row's data:
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_NAME, name);
    initialValues.put(KEY_NUMBER, number);
    initialValues.put(KEY_MESSAGE, message);
    initialValues.put(KEY_ISSELF, isself);

    // Insert it into the database.
    return db.insert(DATABASE_TABLE, null, initialValues);
}

// Delete a row from the database, by rowId (primary key)
public boolean deleteRow(long rowId) {
    String where = KEY_ROWID + "=" + rowId;
    return db.delete(DATABASE_TABLE, where, null) != 0;
}

public void deleteAll() {
    Cursor c = getAllRows();
    long rowId = c.getColumnIndexOrThrow(KEY_ROWID);
    if (c.moveToFirst()) {
        do {
            deleteRow(c.getLong((int) rowId));              
        } while (c.moveToNext());
    }
    c.close();
}

// Return all data in the database.
public Cursor getAllRows() {
    String where = null;
    Cursor c =  db.query(true, DATABASE_TABLE, ALL_KEYS, 
                        where, null, null, null, null, null);
    if (c != null) {
        c.moveToFirst();
    }
    return c;
}

// Get a specific row (by rowId)
public Cursor getRow(long rowId) {
    String where = KEY_ROWID + "=" + rowId;
    Cursor c =  db.query(true, DATABASE_TABLE, ALL_KEYS, 
                    where, null, null, null, null, null);
    if (c != null) {
        c.moveToFirst();
    }
    return c;
}

// Change an existing row to be equal to new data.
public boolean updateRow(long rowId, String name, String number, String message, String isself) {
    String where = KEY_ROWID + "=" + rowId;


    // Create row's data:
    ContentValues newValues = new ContentValues();
    newValues.put(KEY_NAME, name);
    newValues.put(KEY_NUMBER, number);
    newValues.put(KEY_MESSAGE, message);
    newValues.put(KEY_ISSELF, isself);

    // Insert it into the database.
    return db.update(DATABASE_TABLE, newValues, where, null) != 0;
}



/////////////////////////////////////////////////////////////////////
//  Private Helper Classes:
/////////////////////////////////////////////////////////////////////

/**
 * Private class which handles database creation and upgrading.
 * Used to handle low-level database access.
 */
private static class DatabaseHelper extends SQLiteOpenHelper
{
    DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase _db) {
        _db.execSQL(DATABASE_CREATE_SQL);           
    }

    @Override
    public void onUpgrade(SQLiteDatabase _db, int oldVersion, int newVersion) {
        Log.w(TAG, "Upgrading application's database from version " + oldVersion
                + " to " + newVersion + ", which will destroy all old data!");

        // Destroy old database:
        _db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);

        // Recreate new database:
        onCreate(_db);
    }
}

}

Answer 1

A solution could be to parse all your message in a hashmap which will have the phone number as key and an model 'PeopleTexts', this model will have a list of message from the same people (number), number of texts, etc..

After parsing it, you will simply have to iterate over the hashmap and not the db rows.

This the logic. Now some snippets of code

public class PeopleTexts {

   private String phoneNumber;
   private String name;
   private ArrayList<Message> peopleTexts;

   // add setters and getters...

   public int textCount() {
      return peopleTexts.size();
   }

   public void addMessage(Message message) {
      this.peopleTexts.add(message);
   }
}

Now you just have to do in your do...while()

//My Messages is now a Hashmap...

if (cursor.moveToFirst()) {
    do {
         // Process the data:
         // String name = cursor.getString(DBAdapter.COL_NAME);
         String number = cursor.getString(DBAdapter.COL_NUMBER);
         String message = cursor.getString(DBAdapter.COL_MESSAGE);

        if(MyMessages.containsKey(number)) {
          MyMessages.put(number, new PeopleTexts(name, number);
        }

        MyMessages.get(number).addMessage(new Message(number, message);

    } while (cursor.moveToNext());
}

I let you do the rest.