javafx場景對象中的根節點是什么？

Question

我嘗試創建一個場景對象以在其組件上應用css樣式，但是看起來我在創建場景對象時遇到了麻煩。 編譯器說：root不能為null。 有什么建議嗎？

這是我的代碼：

導入javafx.scene.Parent; 導入javafx.scene.Scene;

/ * *要更改此許可證標題，請在“項目屬性”中選擇“許可證標題”。 *要更改此模板文件，請選擇工具| 模板*，然后在編輯器中打開模板。 * /

/ ** * * @author Ahmad * /公共類NewJFrame擴展了javax.swing.JFrame {

private Parent root;
private Parent Parent;

/**
 * Creates new form NewJFrame
 */
public NewJFrame() {
    initComponents();
}

/**
 * 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() {

    jButton1 = new javax.swing.JButton();
    jTextField1 = new javax.swing.JTextField();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jButton1.setText("jButton1");

    jTextField1.setText("jTextField1");

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jButton1)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addComponent(jTextField1, javax.swing.GroupLayout.DEFAULT_SIZE, 297, Short.MAX_VALUE)
            .addContainerGap())
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jButton1)
                .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addContainerGap(266, Short.MAX_VALUE))
    );

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

/**
 * @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(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(NewJFrame.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 NewJFrame().setVisible(true);
        }
    });
}

// Variables declaration - do not modify                     
private javax.swing.JButton jButton1;
private javax.swing.JTextField jTextField1;
// End of variables declaration                   


Scene scene = new Scene(root, 400, 300);

}

Answer 1

您的代碼無法運行，因為您沒有初始化root對象，也沒有將JavaFX與Swing源代碼混合在一起。 JavaFX和Swing是不同的GUI框架。

如果要創建Swing應用程序，則可以遵循此教程： http : //beginnersbook.com/2015/07/java-swing-tutorial/

您可以在以下位置找到JavaFX示例應用程序： http : //docs.oracle.com/javafx/2/get_started/hello_world.htm

或者你可以混合JavaFX和Swing使用JFXPanel （在Swing應用程序的JavaFX，見https://docs.oracle.com/javase/8/javafx/interoperability-tutorial/swing-fx-interoperability.htm ）和SwingNode （擺拳JavaFX應用程序，請參見http://docs.oracle.com/javafx/8/embed_swing/jfxpub-embed_swing.htm ）。