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标题: 帮忙!!!不明白 [打印本页]

作者: lmy5360 时间: 2009-10-5 01:16 AM
标题: 帮忙!!!不明白
import javax.swing.*;//JComponent
import java.awt.*;//frame,layout
import java.awt.event.*;

public class Essays extends GradeActivity implements ActionListener{

private JButton btn1,btn2;
private JTextField F1,F2,F3,F4,F5,F6;

Essays(){

//create a panel with grammar,content,correctlength,spelling
JPanel p1=new JPanel();
p1.setLayout(new GridLayout(6,3,2,4));

p1.add(new JLabel());
p1.add(new JLabel());
p1.add(new JLabel("       Grammar "));
p1.add(F1 = new JTextField(3));

p1.add(new JLabel("       Content "));
p1.add(F2 = new JTextField(3));

p1.add(new JLabel("       Correct length "));
p1.add(F3 = new JTextField(3));

p1.add(new JLabel("       Spelling "));
p1.add(F4 = new JTextField(3));

F1.setHorizontalAlignment(JTextField.RIGHT);
F2.setHorizontalAlignment(JTextField.RIGHT);
F3.setHorizontalAlignment(SwingConstants.RIGHT);
F4.setHorizontalAlignment(SwingConstants.RIGHT);

//create a panel to display total and grade
JPanel p2=new JPanel();
p2.setLayout(new FlowLayout(FlowLayout.CENTER,5,2));

p2.add(new JLabel("Total"));
p2.add(F5 = new JTextField(5));
F5.setEditable(false);

p2.add(new JLabel("       Grade"));
p2.add(F6 = new JTextField(5));
F6.setEditable(false);

//create a panel for buttons
JPanel p3=new JPanel();
p3.setLayout(new FlowLayout(FlowLayout.CENTER,30,30));
p3.add(btn1 = new JButton("Process"));
p3.add(btn2 = new JButton("Exit"));

//create a panel to fit in other panel
JPanel p4=new JPanel();
p4.setLayout(new BorderLayout());
p4.add(p1,BorderLayout.WEST);
p4.add(p2,BorderLayout.SOUTH);

//add panel into frame
add(p3,BorderLayout.SOUTH);
add(p4,BorderLayout.CENTER);

btn1.addActionListener(this);
btn2.addActionListener(this);

}

public void actionPerformed(ActionEvent e){
   if(e.getSource()==btn1){
   double grammar=Double.parseDouble(F1.getText());
   double content=Double.parseDouble(F2.getText());
   double correctLength=Double.parseDouble(F3.getText());
   double spelling=Double.parseDouble(F4.getText());

   double total=grammar+content+correctLength+content;
   F5.setText(String.valueOf(total));

   char Grade=getGrade();
   F6.setText(String.valueOf(Grade));
   }

else{
System.exit(0);
}
}

public static void main(String[]args){
JFrame frame=new JFrame();
frame.setTitle("Grade Activity");
frame.setSize(300,320);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//frame.setLocationRelativeTo(null);
frame.setVisible(true);

}
}

//package lab4;

public class GradeActivity{
  private double score=100;
  private char grade='A';

  public GradeActivity(){super();}

  public GradeActivity(double score, char grade){
   super();
   this.score=score;
   this.grade=grade;
  }

  public double getScore(){
return score;
  }

  public void setScore(double score){
this.score=score;
  }

  public char getGrade(){
if(score>=90)
   return 'A';

else if(score>=80)
   return 'B';

else if(score>=70)
   return 'C';

else if(score>=60)
   return 'D';

else return 'E';
  }

  public void setGrade(char grade){
   this.grade=grade;
  }

  public String toString(){
   return "Total score\t: " + getScore() + "\nGrade\t\t: " + getGrade();
  }
}

//package lab4;

//import java.util.Scanner;
public class testEssays{
  public static void main(String[] args){

   //Scanner input=new Scanner(System.in);
   Essays essay1=new Essays();
   Essays essay2=new Essays(27,17.8,20,26.2);

   System.out.println(essay1);
   System.out.println();
   System.out.println(essay2); //same with ;
   //System.out.println(essay2.toString())

   //System.out.println("Grammar\t\t: " + essay2.getGrammar());
  }
}

C:\Users\Chan\Desktop\lab4\Essays.java:61: cannot find symbol
symbol  : method add(javax.swing.JPanel,java.lang.String)
location: class Essays
add(p3,BorderLayout.SOUTH);
^
C:\Users\Chan\Desktop\lab4\Essays.java:62: cannot find symbol
symbol  : method add(javax.swing.JPanel,java.lang.String)
location: class Essays
add(p4,BorderLayout.CENTER);
^
2 errors

Tool completed with exit code 1

作者: Super-Tomato 时间: 2009-10-5 06:14 AM

原帖由 lmy5360 于 2009-10-5 01:16 AM 发表
import javax.swing.*;//JComponent
import java.awt.*;//frame,layout
import java.awt.event.*;

public class Essays extends GradeActivity implements ActionListener{

private JButton btn1,btn2 ...

//create a panel to fit in other panel
JPanel p4=new JPanel();
p4.setLayout(new BorderLayout());
p4.add(p1,BorderLayout.WEST);
      p4.add(p2,BorderLayout.SOUTH);

      //add panel into frame
      add(p3,BorderLayout.SOUTH);
      add(p4,BorderLayout.CENTER);

      btn1.addActionListener(this);
      btn2.addActionListener(this);

基礎錯誤 : 沒有指定方法屬於哪個對象

作者: lmy5360 时间: 2009-10-5 08:45 AM
那我要怎样，是不是:frame.add(p3,BorderLayout.SOUTH);
frame.add(p4,BorderLayout.CENTER);?

我的BASIC不是很好。。。不好意识！！！！！

作者: lmy5360 时间: 2009-10-5 08:47 AM
难道还要多一个panel？

作者: lmy5360 时间: 2009-10-5 08:49 AM
为么不能显示结果呢？

作者: Super-Tomato 时间: 2009-10-5 11:07 AM

原帖由 lmy5360 于 2009-10-5 08:45 AM 发表
那我要怎样，是不是:frame.add(p3,BorderLayout.SOUTH);
frame.add(p4,BorderLayout.CENTER);?

我的BASIC不是很好。。。不好意识！！！！！

1. 參考 frame class 所提供你的方法
2. 參考上方的增加面板方式, 然後依樣畫葫蘆即可

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