java - 如何使用组合框更改花朵的颜色？ (java)

Question

我只希望我的花朵的花瓣变色。我已经让它与文本字段一起使用，但我认为组合框会更好(所以我的讲师知道他可以选择哪些颜色)。我看到了一些示例，他们会将组合框中的选择显示在文本字段中，但我不确定如何对我的花执行此操作。

简而言之，如何让组合框改变花瓣的颜色以及数组会更好(以及为什么/不)？

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

框架代码:

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                   
}

面板代码:

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

So in short, how do I get the combobox to change the color of my flower petals and would an array be better(and why/not)?

是的，显然。 JComboBox 是一个用户输入控制组件。它允许用户在具有相同类型但不同口味的各种其他项目中选择项目。数组不是组件。它只是一个内部数据结构，我们可以用它来维护(添加、保存、删除)项目，仅此而已。 JComboBox 有一个名为 DefaultComboBoxModel 的模型，它内部包含这样的数据结构，包含元素并为我们管理它们。

但是，您使用 JComboBox 的方式会给您带来麻烦，因为如果您从项目集中选择一个项目，则需要使用 if-else > 或 switch-case 检查是否查找特定元素。显然这就是你现在正在做的事情。作为一个简单的解决方案(但相当垃圾):

  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();

        }
    }); 

我称上述解决方案很垃圾。如果你采用上述方法运行程序，实际上可以直接使用chosenColor实例在paintComponent函数中进行绘制。每当您从colorCombo中选择一种颜色时，您都会看到程序现在以所选颜色项进行响应。但该项目将在组合框中显示为:java.awt.Color[r=xxx,g=xxx,b=xxx]，这可能是您不喜欢的。

了解 Color Chooser 怎么样？并利用它。