Hallo!
Ich möchte gerne mit dem Klick auf den Login-Button auf das testpanel JPanel kommen. Zunächst ohne Benutzername und Passwort zu überprüfen. Aber wenn ich das Programm ausführe, kommt diese Fehlermeldung:
Hier ist ein Teil meines Codes:
Weiß vielleicht jemand von euch worin mein Fehler liegt?
Ich bin für jeden Hinweis oder Tipp dankbar.
Liebe Grüße
Ich möchte gerne mit dem Klick auf den Login-Button auf das testpanel JPanel kommen. Zunächst ohne Benutzername und Passwort zu überprüfen. Aber wenn ich das Programm ausführe, kommt diese Fehlermeldung:
"Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at ui.TestUI$3.actionPerformed(TestUI.java:276)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$500(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)"
Hier ist ein Teil meines Codes:
Java:
package ui;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
import net.miginfocom.swing.MigLayout;
public class TestUI extends JFrame {
private JPanel Cl;
private JLabel lblMediapartner;
private JLabel lblAbmelden;
private JLabel lblKonto;
private JLabel lblWarenkorb;
private JTextField txtSuchen;
private JButton btnAlleArtikel;
private JButton btnKamerasObjektive;
private JButton btnFotozubehr;
private JButton btnStudioBeleuchtung;
private JButton btnVideo;
private JButton btnComputerbedarf;
private JPanel admin;
private JPanel AdminbereichPanel;
private JButton btnAdminbereich;
private JPanel NutzerPanel;
private JPanel anmeldenAbmelden;
private JPanel ausgeloggtPenal;
private JLabel lblRegistrieren;
private JLabel lblLogin;
private JPanel eingeloggtPenal;
private JPanel Center;
private JPanel LoginPanel;
private JLabel lblUsername;
private JLabel lblPasswort;
private JTextField UsernameEingeben;
private JPanel KategoriePanel;
private JLabel lblKategorie;
private JButton btnLogin;
private JButton btnSuchen;
private JPanel testpanel;
private JPasswordField passwordField;
private CardLayout cl;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
TestUI frame = new TestUI();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public TestUI() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 889, 453);
Cl = new JPanel();
Cl.setBorder(new EmptyBorder(5, 5, 5, 5));
Cl.setLayout(new BorderLayout(0, 0));
setContentPane(Cl);
....
// Ab hier Center
Center = new JPanel();
Cl.add(Center, BorderLayout.CENTER);
Center.setLayout(new CardLayout(0, 0));
LoginPanel = new JPanel();
Center.add(LoginPanel, "LoginPanel");
LoginPanel.setLayout(new MigLayout("", "[][][][][][448.00,grow][][][]", "[][][][][][]"));
lblUsername = new JLabel("Username");
LoginPanel.add(lblUsername, "cell 4 2,alignx trailing");
//Textfeld Username
UsernameEingeben = new JTextField();
LoginPanel.add(UsernameEingeben, "cell 5 2,growx");
UsernameEingeben.setColumns(10);
lblPasswort = new JLabel("Passwort");
LoginPanel.add(lblPasswort, "cell 4 4,alignx trailing");
//Loginbutton
btnLogin = new JButton("Login");
btnLogin.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
cl.show(Cl,"testpanel");
}
});
passwordField = new JPasswordField();
LoginPanel.add(passwordField, "cell 5 4,growx");
LoginPanel.add(btnLogin, "cell 6 5");
testpanel = new JPanel();
Center.add(testpanel, "testpanel");
}
}
Weiß vielleicht jemand von euch worin mein Fehler liegt?
Ich bin für jeden Hinweis oder Tipp dankbar.
Liebe Grüße