私のためにこれを見てくれてありがとう、ここに私の問題があります：
MyFrameクラスのIfステートメントに「MyShapeは抽象であり、インスタンス化できません」と表示されています。また、jmenuから選択した形状のインスタンスを作成するようにactionlistenerを完了する方法もわかりません。最後に、Jsliderの寸法をsqaureのサイズと面積に設定し、それをJtextFieldに追加します。
- 「MyShapeは抽象的で、インスタンス化できません」というエラーを修正するにはどうすればよいですか？
- 選択した形状がJsliderにリンクされ、その値がその形状、つまり正方形または円のクラスに追加されるように、ifステートメントを完了する方法に関するヒントはありますか？
- 次に、そのクラスの長さと面積、つまり正方形または円を2つのJtextフィールドに見つけるための2つの方法をどのように出力しますか？
私はあなたが私の道を投げることができるどんな助けも大好きです、あなたが私が理解できるようなプログラミングの初心者のためにそれをするために私がそれをする必要があることを説明してくれれば:)
MyFrame
package assignment;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
public class MyFrame extends javax.swing.JFrame {
public MyFrame() {
// Create the menu
JMenuBar topMenu = new JMenuBar();
this.setJMenuBar(topMenu);
//create the menu button "shapes"
JMenu shapes = new JMenu("Shapes");
topMenu.add(shapes);
//Create the 3 shapes for the menu
JMenuItem square = new JMenuItem("Square");
JMenuItem circle = new JMenuItem("Circle");
JMenuItem triangle = new JMenuItem("Triangle");
//add shapes to menu
shapes.add(circle);
shapes.add(triangle);
shapes.add(square);
//add the menu
setJMenuBar(topMenu);
MyControlPanel pane = new MyControlPanel();
this.add(pane);
}
@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(MyFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(MyFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(MyFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(MyFrame.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 MyFrame().setVisible(true);
}
});
class squareAction implements ActionListener {
public void actionPerformed(ActionEvent e) {
JMenuItem clickedMenu = (JMenuItem) e.getSource();
if (clickedMenu.getText().equals("Square")) {
MyShape ASquare = new MyShape() {
};
} else if (clickedMenu.getText().equals("Circle")) {
MyShape Circle = new MyShape();
} else if (clickedMenu.getText().equals("Triangle")) {
MyShape Triangle = new MyShape();
}
}
}
}
}
Jpanel-MyControlPanel
package assignment;
//import java.awt.FlowLayout;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import javax.swing.GroupLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class MyControlPanel extends javax.swing.JPanel {
JSlider slider;
JLabel sliderLabel;
JLabel sliderdimension;
JLabel blank;
JLabel dl;
JLabel area1;
/**
* Creates new form MyControlPanel
*/
public MyControlPanel() {
slider = new JSlider();
slider.setValue(50);
slider.addChangeListener(new MyChangeAction());
slider.setMajorTickSpacing(10);
slider.setPaintLabels(true);
slider.setPaintTicks(true);
slider.setBounds(300, 50, 100, 50);
sliderLabel = new JLabel("50");
blank = new JLabel(" ");
sliderdimension = new JLabel("Shape Dimension:");
JTextField boundary_length = new JTextField("Boundary Length");
JTextField area = new JTextField("Area");
dl = new JLabel("Boundary Length =");
area1 = new JLabel("Area =");
setLayout(new BorderLayout());
JPanel sliderPanel = new JPanel();
sliderPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 10, 0));
sliderPanel.add(sliderdimension);
sliderPanel.add(sliderLabel);
sliderPanel.add(slider);
sliderPanel.add(dl);
sliderPanel.add(boundary_length);
sliderPanel.add(area1);
sliderPanel.add(area);
this.add(sliderPanel, BorderLayout.PAGE_END);
}
/**
* 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.
*/
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.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)
);
}// </editor-fold>
// Variables declaration - do not modify
// End of variables declaration
public class MyChangeAction implements ChangeListener {
//complete code here
public void stateChanged(ChangeEvent ce) {
int value = slider.getValue();
String str = Integer.toString(value);
sliderLabel.setText(str);
}
} // end class
}
MyShape
package assignment;
public abstract class MyShape
{
double thelength;
double thearea;
public abstract double computeBoundaryLength(double Length);
public abstract double computeArea (double Length);
}
四角
package assignment;
public class ASquare extends MyShape {
@Override
public double computeBoundaryLength(double Length)
{
thelength=(4*Length);
return thelength;
}
@Override
public double computeArea(double Length)
{
thearea=(Length*Length);
return thearea;
}
}
クラスshapeActionはActionListenerを実装します{publicvoidactionPerformed（ActionEvent e）{
JMenuItem clickedMenu = (JMenuItem)e.getSource();
if (clickedMenu.getText().equals("Square")){
//implement abstract methods
MyShape ASquare = new ASquare();
ASquare.addActionListener(new shapeAction());
}
else if (clickedMenu.getText().equals("Circle")){
//implement abstract methods
MyShape ACircle = new ACircle();
ACircle.addActionListener(new shapeAction());
}
else if (clickedMenu.getText().equals("Triangle")){
//implement abstract methods
MyShape ATriangle = new ATriangle();
ATriangle.addActionListener(new shapeAction());