一个JFrame的多个实例

问题描述

在Java中，我有2个类.一个包含一个JFrame.在启动时，将调用该类.显示JFrame.

In Java, I have 2 classes. One contains a JFrame. On startup, that class is called. The JFrame shows.

但是在另一个类中，当我在其自己的框架上按下按钮时，它将打开该类的 new 实例，该实例应该构成另一个框架.但这只是针对已经打开的旧框架...

But in the other class, when I press a button on it's own frame, it opens a new instance of that class which should make another frame. But it just focuses on the old frame already opened...

来源:

FrameToOpen.java

public FrameToOpen() {
    JFrame frame = new JFrame();
    // Just the most simple settings to make it appear...
    frame.setSize(400, 200);
    frame.setVisible(true);
}

OtherClass.java

public OtherClass() {
    JFrame frame = new JFrame();
    JPanel window = new JPanel();
    JButton openFrame = new JButton("Open Frame);
    // Again, just the most simple settings to make it appear with components...
    frame.setSize(400, 200);
    frame.setVisible(true);
    frame.add(window);
    window.setLayout(null);

    window.add(openFrame);
    openFrame.setBounds(5, 5, 100, 30);

    openFrame.addActionListener(this);

    frame.repaint();
    frame.validate();
}

public void actionPerformed(ActionEvent e) {
    Object o = e.getSource();
    if (o == openFrame) {
        // THIS HERE MAKES NEW INSTANCE OF FRAMETOOPEN
        new FrameToOpen();
    }
}

因此，当我按下此按钮时，它不会打开新的框架，而只会聚焦于旧的框架.

So, when I press this button, it doesn't open a new frame, but just focuses on old one.

请帮助.

实际"课程

ServerGUI.java

    if (o == openAdmin) {
        int port;
        try {
            port = Integer.parseInt(portNumber.getText().trim());
        } catch(Exception er) {
            appendEvent("Invalid Port Number.");
            return;
        }

        // FrameToOpen.java. Opening a new instance of that class...
        new ClientGUI("localhost", port, true);
    }

ClientGUI.java

static JFrame frame = new JFrame("Chat Client");
Dimension d = new Dimension(600, 600);
JMenuBar menu = new JMenuBar();

public ClientGUI(String host, int port, boolean isHost) {

        this.isHost = isHost;

        frame.setSize(d);
        frame.setMinimumSize(d);
        //frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.setJMenuBar(menu);
        frame.setVisible(true);


        // Everything else in the class is my buttons, lists, editor panes,
        // and socket handling...

}

推荐答案

您将框架变量定义为static:

static JFrame frame = new JFrame("Chat Client");

因此，无论创建了多少实例，该类仅为该类创建一次.如果您想将static修饰符用作实例字段，请删除它.

so it is created only once for the class, no matter how many instances are created. Remove the static modifier if you want to hava it as an instance field.

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