Update in Sqlite Table via Imagebuttom Android Studio

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I have a project that I am developing in Android Studio where I use a Custom Adapter, an Employee and a Databasehelper.

What happens, I use a database already populated that is in the Assets folder, and this is copied to the Databases directory of the application on its initialization.

I also have a layout where it has a field for research. When searching the user click on a button and the Custom Adapter goes into action to popular Listview.

In Listview there is an Imagebuttom where I am trying to implement a routine where the user click on it so that the item in the list can be recorded as favorite. How was I doing that? Taking the sub-category number sub and the value of the favorite fav and moving on to function public void update(String sub, String fav) on the Databasehelper.

I was unable to implement the click of Imagebuttom, the only place where I could do this was in custom Adapter.

Only now I can not make the data in the table can receive the update, because by clicking on Imagebuttom the application stops working.

Databasehelper.java

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

public class DatabaseHelper extends SQLiteOpenHelper {

private final static String TAG = "Database";
private final Context myContext;
private static final String DATABASE_NAME = "my_db.db";
public static final String SUBCATEGORIA = "sub_categ";
public static final String FAV = "fav";
private static final int DATABASE_VERSION = 2;
private String pathToSaveDBFile;
public DatabaseHelper(Context context, String filePath) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    this.myContext = context;
    pathToSaveDBFile = new    StringBuffer(filePath).append("/").append(DATABASE_NAME).toString();
}
public void prepareDatabase() throws IOException {
    boolean dbExist = checkDataBase();
    if(dbExist) {
        int currentDBVersion = getVersionId();
        if (DATABASE_VERSION > currentDBVersion) {
            deleteDb();
            try {
                copyDataBase();
            } catch (IOException e) {
                Log.e(TAG, e.getMessage());
            }
        }
    } else {
        try {
            copyDataBase();
        } catch (IOException e) {
            Log.e(TAG, e.getMessage());
        }
    }
}
private boolean checkDataBase() {
    boolean checkDB = false;
    try {
        File file = new File(pathToSaveDBFile);
        checkDB = file.exists();
    } catch(SQLiteException e) {
        Log.d(TAG, e.getMessage());
    }
    return checkDB;
}
private void copyDataBase() throws IOException {
    OutputStream os = new FileOutputStream(pathToSaveDBFile);
    InputStream is = myContext.getAssets().open(DATABASE_NAME);
    byte[] buffer = new byte[1024];
    int length;
    while ((length = is.read(buffer)) > 0) {
        os.write(buffer, 0, length);
    }
    is.close();
    os.flush();
    os.close();
}
public void deleteDb() {
    File file = new File(pathToSaveDBFile);
    if(file.exists()) {
        file.delete();
    }
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

public List<Employee> getEmployees(String codigo) {
    SQLiteDatabase db = SQLiteDatabase.openDatabase(pathToSaveDBFile, null, SQLiteDatabase.OPEN_READONLY);
    String query = "SELECT sub_categ, descricao, descrabrev, fav FROM tab_mytabe WHERE TRIM(sub_categ) LIKE '%"+codigo+"%' OR TRIM(descricao) LIKE '%"+codigo+"%'";

    Cursor cursor = db.rawQuery(query, null);
    List<Employee> list = new ArrayList<>();
    while(cursor.moveToNext()) {
        Employee employee = new Employee();
        employee.setSubcategoria(cursor.getString(0));
        employee.setDescricao(cursor.getString(1));
        employee.setDescrabrev(cursor.getString(2));
        employee.setFavorito(cursor.getString(3));
        list.add(employee);
    }
    db.close();
    return list;
}
private int getVersionId() {
    SQLiteDatabase db = SQLiteDatabase.openDatabase(pathToSaveDBFile, null, SQLiteDatabase.OPEN_READONLY);
    String query = "SELECT versao FROM tab_versao";
    Cursor cursor = db.rawQuery(query, null);
    cursor.moveToFirst();
    int v =  cursor.getInt(0);
    db.close();
    return v;
}
}

Customadapter.java

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ArrayAdapter;
import android.widget.ImageButton;
import android.widget.TextView;
import java.util.ArrayList;



public class CustomAdapter extends ArrayAdapter<Employee> implements View.OnClickListener{

Animation animText;
String sub;
String fav;


private ArrayList<Employee> dataSet;
Context mContext;

// View lookup cache
private static class ViewHolder {
    TextView subcategoria;
    TextView descricao;
    TextView descrabrev;
    ImageButton favorito;
}

public CustomAdapter(ArrayList<Employee> data, Context context) {
    super(context, R.layout.lista, data);
    this.dataSet = data;
    this.mContext=context;
}

@Override
public void onClick(View v) {
    int position=(Integer) v.getTag();
    Object object= getItem(position);
    Employee dataModel=(Employee) object;

}


private int lastPosition = -1;

@Override
public View getView(int position, View convertView, final ViewGroup parent) {
    animText = AnimationUtils.loadAnimation(mContext, R.anim.anima_text);

    final Employee dataModel = getItem(position);

    final ViewHolder viewHolder; // view lookup cache stored in tag

    final View result;

    if (convertView == null) {

        viewHolder = new ViewHolder();
        LayoutInflater inflater = LayoutInflater.from(getContext());
        convertView = inflater.inflate(R.layout.lista, parent, false);
        viewHolder.subcategoria = (TextView) convertView.findViewById(R.id.tv_subcategoria);
        viewHolder.descrabrev = (TextView) convertView.findViewById(R.id.tv_descriabreviada);
        viewHolder.descricao = (TextView) convertView.findViewById(R.id.tv_descricao);
        viewHolder.favorito = (ImageButton)convertView.findViewById(R.id.btnFav);

        result=convertView;

        convertView.setTag(viewHolder);
    } else {
        viewHolder = (ViewHolder) convertView.getTag();
        result=convertView;
    }

    viewHolder.subcategoria.setText(dataModel.getSubcategoria());
    viewHolder.descrabrev.setText(dataModel.getDescrabrev());
    viewHolder.descricao.setText(dataModel.getDescricao());


    if (dataModel.getFavorito().equals("1")){
       viewHolder.favorito.setBackgroundResource(R.drawable.ic_fav_seleted);
    }else if (dataModel.getFavorito().equals("0")){
        viewHolder.favorito.setBackgroundResource(R.drawable.ic_fav);
    }

    viewHolder.favorito.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            sub = dataModel.getSubcategoria();
            if (dataModel.getFavorito().equals("1")){
                fav = "0";
            }else if (dataModel.getFavorito().equals("0")){
                fav = "1";
            }
            viewHolder.favorito.startAnimation(animText);
        }
    });

    return convertView;
}
}

How could I fix this?

Note. The update routine was just below the getVersionId() function of the Databasehelper, I withdrew because it was not working. The call for the update function was in viewHolder.favorito.setOnClickListener of the above code.

NX thanks for the reply!

I made the changes in Custom Adapter inserting the codes. This is how:

...
//Ação ao clicar no ImageButtom
viewHolder.favorito.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        sub = dataModel.getSubcategoria();
        if (mOnFavoriteEmployeeListener != null) {
            boolean fav = dataModel.getFavorito().equals("1");
            mOnFavoriteEmployeeListener.onFavorite(dataModel, fav);
        }
        viewHolder.favorito.startAnimation(animText);
    }
});

return convertView;
}

//Interface criada para a ação de update do favorito
interface OnFavoriteEmployeeListener {
void onFavorite(Employee e, boolean fav);
}

private OnFavoriteEmployeeListener mOnFavoriteEmployeeListener;

public void setOnFavoriteEmployeeListener(OnFavoriteEmployeeListener l) {
mOnFavoriteEmployeeListener = l;
}

But in the Activity I couldn’t see where I put the code, because I tried to put it but it’s killing the application.

import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {

private ListView lv;
Animation animText;
ImageView search;
EditText textsearch;
TextView vazio;
String codigo;


//Custom Adapter
ArrayList<Employee> dataModels;
ListView listView;
private static CustomAdapter adapter;
//Final Custom Adapter

DatabaseHelper dbHelper= null;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);


animText = AnimationUtils.loadAnimation(this, R.anim.anima_text);
search = (ImageView)findViewById(R.id.img_Search);
favoritar = (ImageButton)findViewById(R.id.btnFav);
textsearch = (EditText)findViewById(R.id.edt_Search);
vazio = (TextView)findViewById(R.id.textViewV);
vazio.setVisibility(View.INVISIBLE);
lv = (ListView) findViewById(R.id.listview);


search.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        codigo = textsearch.getText().toString();
        search.startAnimation(animText);

        if((verificaCampos(textsearch.getText().toString()) != false)) {
            dbHelper = new DatabaseHelper(MainActivity.this, getFilesDir().getAbsolutePath());
            try {
                dbHelper.prepareDatabase();
            } catch (IOException e) {
                Log.e(TAG, e.getMessage());
            }
            //Datamodels
            List<Employee> list = dbHelper.getEmployees(codigo);
            dataModels = new ArrayList<>();
            for (int i =0; i< list.size(); i++) {
                dataModels.add(list.get(i));
            }

            adapter = new CustomAdapter(dataModels, getApplicationContext());
            lv.setAdapter(adapter);

            if(adapter.isEmpty()){
                vazio.setVisibility(View.VISIBLE);
            }else{
                vazio.setVisibility(View.INVISIBLE);
            }
            //Fim Data Models
        }else{
            mensagem();
        }
    }
});
//Final Pesquisa
}


private boolean verificaCampos(String campo1){
return campo1.trim().length() != 0;
}

}

ERROR

E/AndroidRuntime: FATAL EXCEPTION: main Process: br.com.projeto, PID: 25365 Theme: themes:{default=overlay:system, iconPack:system, fontPkg:system,  com.android.systemui=overlay:system,  com.android.systemui.navbar=overlay:system} java.lang.RuntimeException:  Unable to start activity  ComponentInfo{br.com.projeto/br.com.projeto.MainActivity}:   java.lang.NullPointerException: Attempt to invoke virtual method 'void  br.com.projeto.CustomAdapter.setOnFavoriteEmployeeListener(br.com.projeto.Cus tomAdapter$OnFavoriteEmployeeListener)' on a null object reference at  android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2450) at  android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2510) at  android.app.ActivityThread.-wrap11(ActivityThread.java) at  android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363) at  android.os.Handler.dispatchMessage(Handler.java:102) at  android.os.Looper.loop(Looper.java:148) at  android.app.ActivityThread.main(ActivityThread.java:5461) at  java.lang.reflect.Method.invoke(Native Method) at  com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:72 6) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by:  java.lang.NullPointerException: Attempt to invoke virtual method 'void  br.com.projeto.CustomAdapter.setOnFavoriteEmployeeListener(br.com.projeto.Cus tomAdapter$OnFavoriteEmployeeListener)' on a null object reference at  br.com.projeto.MainActivity.onCreate(MainActivity.java:118) at  android.app.Activity.performCreate(Activity.java:6251) at  android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2403)  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2510)   at android.app.ActivityThread.-wrap11(ActivityThread.java)  at  android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363)  at  android.os.Handler.dispatchMessage(Handler.java:102)  at  android.os.Looper.loop(Looper.java:148)  at  android.app.ActivityThread.main(ActivityThread.java:5461)  at  java.lang.reflect.Method.invoke(Native Method)  at  com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Where am I going wrong?

After the new amendments

After the changes in the code, the logic was as follows:

Customadapter

....
 //Ação ao clicar no ImageButtom
    viewHolder.favorito.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            sub = dataModel.getSubcategoria();
            if (mOnFavoriteEmployeeListener != null) {
                boolean fav = dataModel.getFavorito().equals("1");
                mOnFavoriteEmployeeListener.onFavorite(dataModel, fav);
            }
            viewHolder.favorito.startAnimation(animText);
        }
    });

    return convertView;
}

private OnFavoriteEmployeeListener mOnFavoriteEmployeeListener;

//Interface criada para a ação de update do favorito
interface OnFavoriteEmployeeListener {
    void onFavorite(Employee e, boolean fav);
}

public void setOnFavoriteEmployeeListener(OnFavoriteEmployeeListener l) {
    mOnFavoriteEmployeeListener = l;
}

Mainactivity

...
adapter = new CustomAdapter(dataModels, getApplicationContext());
                adapter.setOnFavoriteEmployeeListener(new CustomAdapter.OnFavoriteEmployeeListener() {
                    public void onFavorite(Employee e, boolean fav) {
                        dbHelper.update(e.getSubcategoria(), fav ? "1" : "0");
                    }
                });
                lv.setAdapter(adapter);

Databasehelper

//Faz o update da tabela ao clicar no ImageButtom
public void update(String sub,  String fav){
    SQLiteDatabase db = SQLiteDatabase.openDatabase(pathToSaveDBFile, null, SQLiteDatabase.OPEN_READWRITE);
    String query = "UPDATE tab_mytabe SET fav = '"+fav+"' WHERE sub_categ = '"+sub+"'";
    db.execSQL(query);
    db.close();
}

However, it is not performing any action in the database and shows no apparent error.

Bank update problem solved

I figured out what was going on, the code part in Activity was that way:

...
dbHelper.update(e.getSubcategoria(), fav ? "1" : "0");
...

When Imagebuttom was clicked the update usually happened only that the value did not change because if the value of the field in the table was "0" when clicking on Imagebuttom the value would still be "0", because the value true is 1, so no change was seen. It was only changing position the numbers that worked perfectly. So with the change was as follows: 

...
dbHelper.update(e.getSubcategoria(), fav ? "0" : "1");
...
android sqlite3

  • The app stops working because some error happens. It has as you insert the error in your question?

  • The error is just below Ack

  • Edit the onCreate putting where is setOnFavoriteEmployeeListener

1 answer

1


In the CustomAdapter create an interface that will be called when a Employee is favored or not favored:

interface OnFavoriteEmployeeListener {
    void onFavorite(Employee e, boolean fav);
}

A field and a set:

private OnFavoriteEmployeeListener mOnFavoriteEmployeeListener;

public void setOnFavoriteEmployeeListener(OnFavoriteEmployeeListener l) {
    mOnFavoriteEmployeeListener = l;
}

And change the getView:

viewHolder.favorito.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        if (mOnFavoriteEmployeeListener != null) {
            boolean fav = dataModel.getFavorito().equals("1");
            mOnFavoriteEmployeeListener.onFavorite(dataModel, fav);
        }
        viewHolder.favorito.startAnimation(animText);
    }
});

In Activity where the CustomAdapter:

customAdapter.setOnFavoriteEmployeeListener(new OnFavoriteEmployeeListener() {
    public void onFavorite(Employee e, boolean fav) {
        databaseHelperInstance.update(e.getSubcategoria(), fav ? "1" : "0");
    }
});

Note that this depends on an instance of DatabaseHelper which was probably created in the onCreate(Bundle) to obtain a ArrayList of Employee.

(In answer to the question of where to place the Istener)

After the Adapter instance:

adapter = new CustomAdapter(dataModels, getApplicationContext());
adapter.setOnFavoriteEmployeeListener(new OnFavoriteEmployeeListener() {
    public void onFavorite(Employee e, boolean fav) {
        dbHelper.update(e.getSubcategoria(), fav ? "1" : "0");
    }
});
lv.setAdapter(adapter);

You may notice that in the error has a NullPointerException because adapter is null. Maybe he was setting the Istener outside the View.OnClickListener.

(Issue 2)

Okay, two things:

The SQLiteOpenHelper is a class to help in open/create/update the database. The existence checks, open data file, etc you made, the SQLiteOpenHelper already does. Following an alternative of the SQLiteOpenHelper that takes advantage of these features compared to some lines of your:

public static class NXDatabaseHelper extends SQLiteOpenHelper {

    private static final String NOME_BANCO_DE_DADOS = "my_db";

    private static final int DATABASE_VERSION = 2;

    public NXDatabaseHelper(Context context) {
        // este super vai verificar se o banco de dados existe. Vai chamar o onCreate se não
        // existe. Se existir mais tem uma versão antige, vai chamar onUpgrade
        super(context, NOME_BANCO_DE_DADOS, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // onCreate só vai ser chamado quando o banco de dados não existir
        // seria o equivalente ao checkDataBase() no original

        // prepareDatabase() faz a cópia de outro banco de dados ao que parece...
        db.execSQL("CREATE TABLE tab_mytabe(" +
                "sub_categ TEXT," +
                "descricao TEXT," +
                "descrabrev TEXT," +
                "fav integer" +
                ");");
        // faça a cópia aqui, copyDataBase(), se precisar
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // if (dbExist) {
        switch (oldVersion) {
            // versões anteriores do banco de dados
            // if (DATABASE_VERSION > currentDBVersion)
            case 0:
                // o que mudou da primeira versão para a versão 2?
            case 1:
                // deleteDb();
                db.execSQL("DROP TABLE tab_mytabe;");

                // try {
                //     copyDataBase();
                // } catch (IOException e) {
                //     Log.e(TAG, e.getMessage());
                // }
                onCreate(db);
        }
        // }
    }

    public List<Employee> getEmployees(String codigo) {
        SQLiteDatabase db = getReadableDatabase();
        String query = "SELECT sub_categ, descricao, descrabrev, fav" +
                " FROM tab_mytabe" +
                " WHERE TRIM(sub_categ) LIKE '%" + codigo + "%'" +
                " OR TRIM(descricao) LIKE '%" + codigo + "%'";

        Cursor cursor = db.rawQuery(query, null);
        List<Employee> list = new ArrayList<>();

        // só para ter certeza das posições das colunas
        final int subcat = cursor.getColumnIndex("sub_categ");
        final int descricao = cursor.getColumnIndex("descricao");
        final int descrabrev = cursor.getColumnIndex("descrabrev");
        final int fav = cursor.getColumnIndex("fav");

        while (cursor.moveToNext()) {
            Employee employee = new Employee();

            employee.setSubcategoria(cursor.getString(subcat));
            employee.setDescricao(cursor.getString(descricao));
            employee.setDescrabrev(cursor.getString(descrabrev));
            employee.setFavorito(cursor.getLong(fav) != 0);

            list.add(employee);
        }

        cursor.close(); // o cursor deve ser fechado depois do uso
        db.close();

        return list;
    }

    public void update(String subCategoria, boolean fav) {
        SQLiteDatabase db = getReadableDatabase();

        ContentValues campos = new ContentValues(); // é como um Bundle

        campos.put("fav", fav ? 1 : 0);

        // Equivalente:
        // UPDATE tab_mytabe SET fav="0 ou 1" WHERE sub_categ='subcategoria';
        db.update("tab_mytabe", campos, "sub_categ='" + subCategoria + '\'', null);
    }
}

In the onCreate needs to be declared outside the View.OnClickListener() of search because a new instance will be created every time something is searched. The changes are few, as dbHelper is initialized outside the Systener, where the OnFavoriteEmployeeListener and others who are commented to compare with the original code:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    animText = AnimationUtils.loadAnimation(this, R.anim.anima_text);
    search = (ImageView) findViewById(R.id.img_Search);
    favoritar = (ImageButton) findViewById(R.id.btnFav);
    textsearch = (EditText) findViewById(R.id.edt_Search);
    vazio = (TextView) findViewById(R.id.textViewV);
    vazio.setVisibility(View.INVISIBLE);
    lv = (ListView) findViewById(R.id.listview);

    final NXDatabaseHelper dbHelper = new NXDatabaseHelper(MainActivity.this);

    search.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            codigo = textsearch.getText().toString();
            search.startAnimation(animText);

            //if ((verificaCampos(textsearch.getText().toString()) != false)) { // Por que?
            if (verificaCampos(textsearch.getText().toString())) {
                // não é preciso do arquivo, já que SQLiteOpenHelper cria o arquivo
                dbHelper = new NXDatabaseHelper(MainActivity.this);
                // try {
                //     dbHelper.prepareDatabase();
                // } catch (IOException e) {
                //     Log.e(TAG, e.getMessage());
                // }
                // Datamodels
                // uma lista que é copiada para a outra e descartada em seguida...
                // List<Employee> list = dbHelper.getEmployees(codigo);
                // dataModels = new ArrayList<>();
                // for (int i = 0; i < list.size(); i++) {
                //     dataModels.add(list.get(i));
                // }
                dataModels = dbHelper.getEmployees(codigo);

                adapter = new CustomAdapter(dataModels, getApplicationContext());
                adapter.setOnFavoriteEmployeeListener(new OnFavoriteEmployeeListener() {
                    public void onFavorite(Employee e, boolean fav) {
                        dbHelper.update(e.getSubcategoria(), fav);
                    }
                });
                lv.setAdapter(adapter);

                if (adapter.isEmpty()) {
                    vazio.setVisibility(View.VISIBLE);
                } else {
                    vazio.setVisibility(View.INVISIBLE);
                }
                //Fim Data Models
            } else {
                mensagem();
            }
        }
    });
    //Final Pesquisa
}

Since we don’t have the full code of DatabaseHelper original, I’m assuming the columns aren’t being added, or something like that.

  • I entered the codes as you indicated. The only change I had to make was in the excerpt: Adapter.setOnFavoriteEmployeeListener(new Onfavoriteemployeelistener() Which looked like this: Adapter.setOnFavoriteEmployeeListener(new Customadapter.Onfavoriteeyemployeelistener(){ ... } As he was not recognizing Onfavoriteemployeelistener. Now has not locked the application, however it is not running any action in the database.

  • No action you refer to does not even write to the database? Or is the Switch not even called? Changing the subject slightly, read https://developer.android.com/training/basics/data-storage/databases.html?hl=pt-br as the SQLiteOpenHelper already makes one of the steps you made how to check whether the database already exists or not and etc.

  • NX1125, does not update to the database.

  • Use adapter.notifyDataSetChanged() after dbHelper.update(e.getSubcategoria(), fav) inside the Istener. This will make the ListView be notified that the Adapter has changed.

  • NX1125, I ended up deleting the previous comment, to redo it, because it would not give time to edit it. All right, I’m going to use Adapter.notifyDataSetChanged() to refresh the listview. Thanks for the hint of the link Android Veloper, really is very explanatory. I will have to redo the code of my project because I need to improve a lot on it.

  • The notifyDataSetChanged() command did not work. I believe that because the system popular the listview after the database query. After the query the bank is closed with a db.close(). Then I think I would have to redo the query to see the changes in listview.

  • A question regarding the issue two of the code, the creation of the table is necessary even in case the application already has a populated database, and this will be copied from the Assets directory to the Databases folder on the user’s device?

  • Yes. You will also need to copy the information from the original database if using SQLiteOpenHelper

  • I’m still confused about this whole databank thing. For example, the flock will be copied from the Assets directory to the Databases directory. Without creating any table and no database the application works normally because the database was copied from one directory to the other. Why is it necessary to create the table again and copy the information? What is the difference, in the specific case of this project, between copying the ja gang with the data and creating it to then copy the information?

  • Another question, in the case of this code it is possible to set the onclick in the listview itself considering that the imagebuttom is already set?

  • Use SQLiteOpenHelper if necessary. If you already have the table then you can ignore the code alternative. This second question would be better to create a new question in the OS.

  • Thanks for the tips @NX1125

  • It would be better to use the Asynctask class in a project like this that needs to update the database and show the results in real time?

  • That would also be good to ask a separate question.

  • Okay. I’m going to ask you a new question.

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