Hi,
I am developing a J2ME application but i have some trouble when I want to display a new form (contained in a class).
My Midlet class is like that
public class StoreDataMidlet extends MIDlet{
public StoreDataConnex StoreInfosConnex ;
private static Display mDisplay;
private ChaineConnexion connexForm; // Form which is opened when my Midlet starts
public void StoreDataMidlet() {
}
public void startApp() {
mDisplay = Display.getDisplay(this);
if (connexForm == null) {
connexForm = new ChaineConnexion(this);
} else {
connexForm.DrawComponents(); // DrawComponents is the method which initialize my form components
}
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
/* public static Display getDisplay ()
{
return mDisplay;
}*/
}
My Midlet starts with the second class wich contains two commands: the first one opens an Alert and the second has to open an other Form in a third class. But it doesn't work. I don't know why the third form cant be opened (It appears: NullPointerException). My the second class looks like below
public class ChaineConnexion implements CommandListener{
private Display mDisplay;
public Command mOkCommand;
public Command mExitCommand;
public TextField usernameTextField;
public TextField passwordTextField;
private ConnexionForm connexForm;
private StoreDataMidlet midlet ;
private Form formulaireConnexion;
public ChaineConnexion(StoreDataMidlet midlet) {
mDisplay = Display.getDisplay(midlet);
DrawComponents();
mDisplay.setCurrent(formulaireConnexion);
}
public void DrawComponents()
{
formulaireConnexion = new Form("Formulaire Connexion");
usernameTextField = new TextField("Login", "user", 20, TextField.ANY);
passwordTextField = new TextField("Mot de Passe", "user", 20, TextField.PASSWORD);
formulaireConnexion.append(usernameTextField);
formulaireConnexion.append(passwordTextField);
mOkCommand = new Command("Valider", Command.ITEM, 0);
mExitCommand = new Command("Quitter", Command.EXIT, 0);
formulaireConnexion.addCommand(mExitCommand);
formulaireConnexion.addCommand(mOkCommand);
formulaireConnexion.setCommandListener(this);
}
public void commandAction(Command c, Displayable d) {
if (c == mOkCommand){
showAlert("Succes","Login et Mot de passe changé"); // Alert appears but
} else if (c == this.mExitCommand){
connexForm = new ConnexionForm(midlet); // This form doesnt work
}
}
private void showAlert( String title, String message)
{
//Display display = Display.getDisplay(midlet);
Alert alert = new Alert(title);
alert.setString(message);
alert.setTimeout(Alert.FOREVER);
mDisplay.setCurrent(alert); // this line has been changed
}
}
My third class that doesnt appear is like below
public class ConnexionForm implements CommandListener {
private Display mDisplay;
public Command mConnectionCommand;
public Command mExitCommand;
public TextField usernameTextField;
public TextField passwordTextField;
private StoreDataConnex storeData ;
private Alert alert;
public Form formulaireConnexion;
private StoreDataMidlet midlet;
public ConnexionForm(StoreDataMidlet midlet) throws RecordStoreException{
mDisplay = Display.getDisplay(midlet);
DrawComponents();
mDisplay.setCurrent(formulaireConnexion);
}
public void DrawComponents() throws RecordStoreException{
try {
formulaireConnexion = new Form("Formulaire Connexion");
usernameTextField = new TextField("Login", storeData.getLogin(), 20, TextField.ANY);
passwordTextField = new TextField("Mot de Passe", storeData.getPassword(), 20, TextField.PASSWORD);
formulaireConnexion.append(usernameTextField);
formulaireConnexion.append(passwordTextField);
mConnectionCommand = new Command("Connexion", Command.ITEM, 0);
mExitCommand = new Command("Quitter", Command.EXIT, 0);
formulaireConnexion.addCommand(mExitCommand);
formulaireConnexion.addCommand(mConnectionCommand);
// formulaireConnexion.setCommandListener(this);
} catch (IOException ex) {
ex.printStackTrace();
}
}
public void commandAction(Command c, Displayable d) {
if (c == mConnectionCommand) {
} else if(c == mExitCommand) {
midlet.notifyDestroyed();
}
}
}
Please help me to know what wrong with my code!!!
