如何使用組合框更改花朵的顏色？ （java）

Question

我只希望花的花瓣變色。 我已經將其與文本字段一起使用，但是我決定組合框會更好（因此我的講師知道他可以選擇哪種顏色）。 我看到了一些示例，它們將使組合框中的選擇顯示在文本字段中，但是我不確定如何用我的花朵進行選擇。

簡而言之，我如何獲得組合框來更改花瓣的顏色，並且陣列會更好（為什么呢？

圖片-http: //s903.photobucket.com/user/Nicole_Pretorius/media/Flowers_zps936f6f40.jpg.html

框架代碼：

package Versie4;


public class FrameFlowers extends javax.swing.JFrame {


public FrameFlowers() {
    initComponents();
    setSize(900, 600);
    setContentPane(new PanelFlowers());
}


@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 400, Short.MAX_VALUE)
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGap(0, 300, 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(FrameFlowers.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(FrameFlowers.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(FrameFlowers.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(FrameFlowers.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 FrameFlowers().setVisible(true);
        }
    });
}
// Variables declaration - do not modify                     
// End of variables declaration                   
}

面板代碼：

package Versie4;
import java.awt.Color;
import java.awt.Graphics;

public class PanelFlowers extends javax.swing.JPanel {
private int amount;
private String color = "";

public PanelFlowers() {
    initComponents();
    repaint();
}

public void paintComponent(Graphics g){
    super.paintComponent(g);

    int teller;

    g.setColor(Color.RED);  //flowerpot
    g.fillRect(300, 350, 500, 100);

    int x = 1;
    for (teller=1; teller <= amount ;teller++) { 

        //Flower 1
    g.setColor(Color.GREEN);  //stem
    g.fillRect(320 + x, 250, 10, 100);


        switch (color) {            //Colours of petals
            case "red":
                g.setColor(Color.red);
                break;
            case "blue":
                g.setColor(Color.blue);
                break;
            case "yellow":
                g.setColor(Color.yellow);
                break;
            case "orange":
                g.setColor(Color.orange);
                break;
            case "pink":
                g.setColor(Color.PINK);
                break;
            case "purple":
                g.setColor(new Color(102, 0, 204));
                break;
        }

    g.fillOval(304 + x, 190, 40, 40); //petals
    g.fillOval(330 + x, 210, 40, 40);
    g.fillOval(320 + x, 240, 40, 40);
    g.fillOval(290 + x, 240, 40, 40);
    g.fillOval(280 + x, 210, 40, 40);


    g.setColor(Color.YELLOW);  //pistil
    g.fillOval(312 + x, 225, 25, 25);

    x = teller * 80;




    }


}


@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    lblamount = new javax.swing.JLabel();
    txtamount = new javax.swing.JTextField();
    lblcolor = new javax.swing.JLabel();
    txtcolor = new javax.swing.JTextField();
    btngrow = new javax.swing.JButton();
    btnreset = new javax.swing.JButton();
    colorCombo = new javax.swing.JComboBox();

    lblamount.setText("Amount: ");

    txtamount.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            txtamountActionPerformed(evt);
        }
    });

    lblcolor.setText("Color: ");

    txtcolor.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            txtcolorActionPerformed(evt);
        }
    });

    btngrow.setText("Grow!");

    btnreset.setText("Reset Size");

    colorCombo.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "red", "blue", "yellow", "orange", "pink", "purple" }));
    colorCombo.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            colorComboActionPerformed(evt);
        }
    });

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
    this.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()
                    .addContainerGap()
                    .addComponent(lblamount)
                    .addGap(18, 18, 18)
                    .addComponent(txtamount, javax.swing.GroupLayout.PREFERRED_SIZE, 57, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(41, 41, 41)
                    .addComponent(lblcolor)
                    .addGap(18, 18, 18)
                    .addComponent(txtcolor, javax.swing.GroupLayout.PREFERRED_SIZE, 59, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(60, 60, 60)
                    .addComponent(btngrow)
                    .addGap(18, 18, 18)
                    .addComponent(btnreset))
                .addGroup(layout.createSequentialGroup()
                    .addGap(211, 211, 211)
                    .addComponent(colorCombo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
            .addContainerGap(230, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(lblamount)
                .addComponent(txtamount, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(lblcolor)
                .addComponent(txtcolor, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(btngrow)
                .addComponent(btnreset))
            .addGap(42, 42, 42)
            .addComponent(colorCombo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(350, Short.MAX_VALUE))
    );
}// </editor-fold>                        

private void txtamountActionPerformed(java.awt.event.ActionEvent evt) {                                          
amount = Integer.parseInt(txtamount.getText());

color = this.txtcolor.getText();
repaint();
}                                         

private void txtcolorActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
}                                        

private void colorComboActionPerformed(java.awt.event.ActionEvent evt) {                                           
    // TODO add your handling code here:
}                                          

// Variables declaration - do not modify                     
private javax.swing.JButton btngrow;
private javax.swing.JButton btnreset;
private javax.swing.JComboBox colorCombo;
private javax.swing.JLabel lblamount;
private javax.swing.JLabel lblcolor;
private javax.swing.JTextField txtamount;
private javax.swing.JTextField txtcolor;
// End of variables declaration                   
}

Answer 1

簡而言之，我如何獲得組合框來更改花瓣的顏色，並且陣列會更好（為什么呢？

是的，顯然。 JComboBox是用戶輸入控制組件。 它允許用戶從具有相同類型但口味不同的其他各種項目中選擇一個項目。 數組不是組件。 它只是一個內部數據結構，我們可以用來維護（添加，保存，刪除）項目，僅此而已。 JComboBox擁有一個稱為DefaultComboBoxModel模型，該模型內部包含此類數據結構並包含元素並為我們管理它們。

但是，使用JComboBox的方式會給您帶來麻煩，因為如果您從一組項目中選擇一個項目，則需要使用if-else或switch-case檢查來查找特定元素。 顯然，您現在正在做什么。 作為一個簡單的解決方案（但很垃圾）：

  public class PanelFlowers extends javax.swing.JPanel {

     private int amount;
     // private String color = "";
     Color chosenColor;
     public PanelFlowers() {
         initComponents();
         // repaint(); // <--- no need to call repaint in constructor
     }

  private void initComponents() {

     // your other code------------

   DefaultComboBoxModel model = new DefaultComboBoxModel();
   model.addElement(new Color(152, 52, 152));
   model.addElement(new Color(152, 12, 52));
   model.addElement(new Color(152, 142, 120));
   colorCombo.setModel(model);


   colorCombo.addItemListener(new ItemListener() {


        @Override
        public void itemStateChanged(ItemEvent e) {

            JComboBox comb = (JComboBox)e.getSource();
            chosenColor = (Color) comb.getSelectedItem();
            repaint();

        }
    }); 

我稱上述解決方案為垃圾。 如果采用上述方法運行程序，則實際上可以直接使用chosenColor實例在paintComponent函數內部進行繪制。 每當您從colorCombo選擇一種顏色時，您都會看到該程序現在會響應所選的顏色項目。 但是，該項目將在comboBox中顯示為： java.awt.Color[r=xxx,g=xxx,b=xxx] ，這可能是您不希望看到的。

如何學習和使用“ 顏色選擇器” 。