Question

我正在尝试在Java中创建一个全屏应用程序。我有三个扩展JPanel的类，我想添加它。每个都有自己的布局和组件。

我第一次尝试使用MiG Layout。我有一个扩展JFrame作为主窗口的类。此类有一个使用MiG的面板，另外三个类被添加到此面板中。现在主面板出现在左上方，我希望它出现在中心。我尝试制作一个“包装”面板，我可以使用BorderLayout集中，但这似乎不起作用。我尝试了其他一些排列，但我觉得这应该有效，我不明白为什么不是。

以下是相关代码：

public class MainWindow extends JFrame {

private final int WINDOW_WIDTH = 800; //Width
private final int WINDOW_HEIGHT = 800; //Height

//three panel objects
private final IntroPanel header;
private final InputPanel input;
private final SubmitPanel submit;

//for fullscreen
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

public MainWindow() throws MalformedURLException {

    //set things like size, close operation, etc
    this.Build();

    //Create a MiG layout
    MigLayout layout = new MigLayout("wrap 3");

    //panel which will hold three panels
    JPanel panel = new JPanel(layout);

    //initiate the three panels we need for user actions
    header = new IntroPanel();
    input = new InputPanel();
    submit = new SubmitPanel();


    panel.add(header, "span, center, gapbottom 15");
    panel.add(input, "span, center, gapbottom 15");
    panel.add(submit,"span, center, gapbottom 15");

    this.setLayout(new BorderLayout());
    add(panel, BorderLayout.CENTER);


    //set the windows position to the center of the screen
    setLocationRelativeTo(null);
    //Make the window visable
    setVisible(true);
}

Answer 1

this.setLayout(new BorderLayout());
add(panel, BorderLayout.CENTER);

而不是BorderLayout使用GridBagLayout：

this.setLayout(new GridBagLayout());
add(panel, new GridBagConstraints());

Answer 2

避免将面板直接添加到JFrame。请改用this.setContentPane(panel)。这样您就不需要任何额外的布局。使用MigLayout为mainPanel添加LayoutContraint填充。

public class MigLayoutTests {

    public static void main(String[] args) {

        JFrame frame = new JFrame();
        frame.setSize(500, 500);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);

        JPanel mainPanel = new JPanel(new MigLayout("debug, fill", "", ""));
        mainPanel.add(new JLabel("Hello World"), "align left bottom");

        frame.setContentPane(mainPanel);
        frame.setVisible(true);

    }

}

将JPanel放在全屏JFrame的中心

2 个答案: