java - JFrame.setExtendedState() 在 Mac 上无法正常工作

Question

我正在使用 javax.swing.JFrame 和 java 1.8.0_211，并且我希望我的 JFrame 在整个屏幕上最大化。

我正在使用以下代码:

public class MitarbeiterUI extends javax.swing.JFrame {


    /**
     * Creates new form MitarbeiterUI
     */
    public MitarbeiterUI(Mitarbeiter mitarbt) {

        initComponents();

        this.setExtendedState(MAXIMIZED_BOTH);
        this.setSize((int)Toolkit.getDefaultToolkit().getScreenSize().getWidth(), (int)Toolkit.getDefaultToolkit().getScreenSize().getHeight());
        this.setVisible(true);
    }

    [...]
}

但这只会导致窗口水平与屏幕对齐，而不是垂直对齐。它确实适用于 Windows 和 Linux 系统，因此它必须是 Mac 特定的问题。有什么办法可以解决这个非常烦人的错误吗？

编辑:可执行代码示例

import java.awt.Toolkit;

public class SecondFrame extends javax.swing.JFrame {

/**
 * Creates new form SecondFrame
 */
public SecondFrame() {
    initComponents();

    this.setExtendedState(MAXIMIZED_BOTH);
    this.setSize((int)Toolkit.getDefaultToolkit().getScreenSize().getWidth(), (int)Toolkit.getDefaultToolkit().getScreenSize().getHeight());
    this.setVisible(true);
}

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jPanel1 = new javax.swing.JPanel();
    jLabel1 = new javax.swing.JLabel();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    addComponentListener(new java.awt.event.ComponentAdapter() {
        public void componentResized(java.awt.event.ComponentEvent evt) {
            formComponentResized(evt);
        }
    });

    jPanel1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 563, Short.MAX_VALUE)
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 877, Short.MAX_VALUE)
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(layout.createSequentialGroup()
                    .addGap(134, 134, 134)
                    .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGroup(layout.createSequentialGroup()
                    .addContainerGap()
                    .addComponent(jLabel1)))
            .addContainerGap(25, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jLabel1)
            .addGap(19, 19, 19)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(241, Short.MAX_VALUE))
    );

    pack();
}// </editor-fold>                        

private void formComponentResized(java.awt.event.ComponentEvent evt) {                                      
    jLabel1.setText("W: " + this.getWidth() + ", H: " + this.getHeight());
}                                     

/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(SecondFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(SecondFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(SecondFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(SecondFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new SecondFrame().setVisible(true);
        }
    });
}

// Variables declaration - do not modify                     
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanel1;
// End of variables declaration                   
}

Edit2:问题似乎出在我们使用的 Mac 的屏幕尺寸上。它们的分辨率都高于全高清，但都会自动缩小到 1440 至 900p，这使得我们在类里面使用的 JPanel 比调整大小的屏幕更大，从而在底部被截断。所以我想现在的问题是如何告诉这些 Mac 不要调整屏幕大小，或者如何向 JFrame 添加滚动条而无需重做整个类。

Answer 1

this.setExtendedState(MAXIMIZED_BOTH);
this.setSize((int)Toolkit.getDefaultToolkit().getScreenSize().getWidth(), (int)Toolkit.getDefaultToolkit().getScreenSize().getHeight());
this.setVisible(true);

使用 setExtendedState(...) 的要点是您不需要使用 setSize(...) 方法。

所以代码应该是:

this.setExtendedState(MAXIMIZED_BOTH);
this.setVisible(true);

setSize() 语句会覆盖 setExtendedState(...) 方法计算的大小。