我正在做一些計算程序,用戶可以在其中輸入他們想要訂購的飲料的數量,並且按鈕將計算他們需要支付的金額。如果他們檢查了交付箱,將會增加30美元的運費。我正在使用isSelected檢查它們是否勾選了是否勾選,但它不起作用。我得到的錯誤是「方法isSelected()未定義類型複選框」。isSelected()複選框錯誤
import java.awt.*;
import java.awt.event.*;
public class hwextend{
static Frame frm = new Frame("Action Event");
static Checkbox ckb1 = new Checkbox("Delivery");
static Button btn = new Button("Calculate");
static TextField textfield1 = new TextField();
static TextField textfield2 = new TextField();
static TextField textfield3 = new TextField();
static TextField textfield4 = new TextField();
static TextField textfield5 = new TextField();
public static void main(String[] args) {
// TODO Auto-generated method stub
GridLayout grid = new GridLayout (7,3);
btn.addActionListener(new ActListener());
frm.setLayout(grid);
frm.setSize(400,200);
frm.setBackground(Color.pink);
Label lab1 = new Label ("Tea Series");
Font font1 = new Font(null,Font.BOLD,12);
lab1.setFont(font1);
frm.add(lab1);
frm.add(new Label(""));
frm.add(new Label(""));
frm.add(new Label("Black Tea"));
frm.add(new Label("$70"));
frm.add(textfield1);
frm.add(new Label("Green Tea"));
frm.add(new Label("$70"));
frm.add(textfield2);
Label lab2 = new Label ("Special Flavor Series");
lab2.setFont(font1);
frm.add(lab2);
frm.add(new Label(""));
frm.add(new Label(""));
frm.add(new Label("Alpine Tea"));
frm.add(new Label("$80"));
frm.add(textfield3);
frm.add(new Label("Stewed Oolong Tea"));
frm.add(new Label("$80"));
frm.add(textfield4);
frm.add(btn);
frm.add(ckb1);
frm.add(textfield5);
frm.addWindowListener(new WindowAdapter()
{
public void windowClosing (WindowEvent Event) {
System.exit (0);
}
}
);
frm.setVisible(true);
}
static class ActListener implements ActionListener{
public void actionPerformed(ActionEvent e) {
int a = Integer.parseInt(textfield1.getText().toString());
int b = Integer.parseInt(textfield2.getText().toString());
int c = Integer.parseInt(textfield3.getText().toString());
int d = Integer.parseInt(textfield4.getText().toString());
if (ckb1).isSelected()){
textfield5.setText(String.valueOf((a+b)*70+(c+b)*80)+30);
}
else {
textfield5.setText(String.valueOf((a+b)*70+(c+b)*80));
}
}
}
}