JPanel / JFrame自动调整大小。 JAVA

Question

I so have made a GUI for a Chat that im currently working on. Its aaaaalmost done but the only thing is the automatically resizing when dragging the window. I can't find out why its happend and this was my last chance. So I really need help from you guys! Im kinda out of idea

The code is here:

ClientGUI(String host, int port) {

    super("Chat Client");
    defaultPort = port;
    defaultHost = host;



    // The CenterPanel which is the chat room
    MessageText = new JTextArea("Welcome to the Chat room\n");
    JPanel centerPanel = new JPanel();
    MessageText.setWrapStyleWord(true);
    MessageText.setLineWrap(true);

    centerPanel.setLayout(null);
    JScrollPane scrollPane = new JScrollPane(MessageText);
    scrollPane.setBounds(0, 0, 584, 486);
    getContentPane().add(scrollPane);
    MessageText.setEditable(false);
    getContentPane().add(centerPanel, BorderLayout.CENTER);
    WriteMessage = new JTextField("Write your username here!");
    WriteMessage.setBounds(0, 492, 584, 35);
    centerPanel.add(WriteMessage);
    WriteMessage.setColumns(234);
    WriteMessage.setBackground(Color.WHITE);

    // the 3 buttons
    Login = new JButton("Login");
    Login.setBounds(594, 338, 125, 35);
    centerPanel.add(Login);
    Logout = new JButton("Logout");
    Logout.setBounds(594, 469, 125, 35);
    centerPanel.add(Logout);
    Logout.addActionListener(this);
    Logout.setEnabled(false);       // you have to login before being able to logout
    Online = new JButton("Online");
    Online.setBounds(594, 403, 125, 35);
    centerPanel.add(Online);
    Online.addActionListener(this);
    Online.setEnabled(false);       // you have to login before being able to Who is in
    JLabel PortNumberText = new JLabel("Port Number:  ");
    PortNumberText.setBounds(594, 83, 144, 20);
    centerPanel.add(PortNumberText);
    PortNumber = new JTextField("" + port);
    PortNumber.setBounds(594, 114, 129, 20);
    centerPanel.add(PortNumber);
    PortNumber.setHorizontalAlignment(SwingConstants.RIGHT);

    JLabel ServerText = new JLabel("Server Address:  ");
    ServerText.setBounds(594, 21, 240, 20);
    centerPanel.add(ServerText);
    // the two JTextField with default value for server address and port number
    ServerAddress = new JTextField(host);
    ServerAddress.setBounds(594, 52, 129, 20);
    centerPanel.add(ServerAddress);
    Login.addActionListener(this);
    WriteMessage.requestFocus();

    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(760, 570);
    setVisible(true);




}

A picture what I mean

Answer 1

Don't use a null layout. Don't use setBounds(). Swing was designed to be used with layout managers.

Resizing of components can only be done when you use a layout manager. Read the section from the Swing tutorial on Layout Manager for more information and examples. You can always use multiple panels each with a different layout manager to get your desired results.

Also follow Java naming conventions. Variable names should NOT start with an upper case character. Half the time your names are correct and half the time they are not. Be consistent!

Answer 2

You are using a Null-Layout (absolute positioning), and this means you have to take care of everything related to layout yourself. Better use a LayoutManager .

Answer 3

Alright so I just made a border layout all from start so I guess its all good, Thanks everyone for helping! Doesnt look that professional. So yeah, Might be some more updates later on :)