Question

我目前正在为我的Java类工作。它要求我们在文件中更改一些代码以添加joptionpane对话框而不是已存在的字段。以下是作业的确切措辞：

查看Flora的源代码。 java文件。在包含任何消息框的所有行的开头插入注释标记（//），但MessageBox声明语句除外。在注释掉的行的正下方，插入新代码以生成替换消息框的JOptionPane对话框。使用相同的标题，提示和按钮。不要忘记导入必要的Swing包。

我无法弄清楚如何添加一个JOptionPane框。我为joptionpane导入了swing，但我需要协助设置框

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JOptionPane;

public class Flora extends Frame implements ActionListener
{
   MessageBox savedBox;
   MessageBox errorBox;
   DataOutputStream output;
   //Construct components
   Panel dataFields = new Panel();
   Panel firstRow = new Panel();
   Panel secondRow = new Panel();
   Panel thirdRow = new Panel();
   Panel fourthRow = new Panel();
   Panel fifthRow = new Panel();
   Panel sixthRow = new Panel();
   Panel buttonArea= new Panel();

   Button newSticker = new Button("New Sticker");
   Button renewal = new Button("Renewal");

   //Label vinLabel = new Label("Enter Vehicle VIN number:    ");
      //TextField vin = new TextField(20);
   //Label yearLabel = new Label("Year:   ");
      //TextField year = new TextField(4);
   //Label makeLabel = new Label("Make:               ");
      //TextField make = new TextField(10);
   //Label modelLabel = new Label("Model:");
      //TextField model = new TextField(10);
   //Label firstNameLabel = new Label("Enter First Name:       ");
      //TextField firstName = new TextField(15);
   //Label lastNameLabel = new Label("Enter Last Name:");
      //TextField lastName = new TextField(20);
   //Label addressLabel = new Label("Enter Flora Address:");
      //TextField address = new TextField (35);

   public static void main(String[] args)
   {
      Flora window = new Flora();
      window.setTitle("Flora City Stickers");
      window.setSize(450, 250);
      window.setVisible(true);
   }

   public Flora()
   {
     //Set background and layout managers
     setBackground(Color.magenta);
     setLayout(new BorderLayout());
        dataFields.setLayout(new GridLayout(6,1));
        FlowLayout rowSetup = new FlowLayout(FlowLayout.LEFT,5,2);
           firstRow.setLayout(rowSetup);
           secondRow.setLayout(rowSetup);
           thirdRow.setLayout(rowSetup);
           fourthRow.setLayout(rowSetup);
           fifthRow.setLayout(rowSetup);
           sixthRow.setLayout(rowSetup);
        buttonArea.setLayout(new FlowLayout());

     //Add fields to rows
     firstRow.add(vinLabel);
     firstRow.add(yearLabel);
     firstRow.add(makeLabel);
     firstRow.add(modelLabel);

     secondRow.add(vin);
     secondRow.add(year);
     secondRow.add(make);
     secondRow.add(model);

     thirdRow.add(firstNameLabel);
     thirdRow.add(lastNameLabel);

     fourthRow.add(firstName);
     fourthRow.add(lastName);

     fifthRow.add(addressLabel);

     sixthRow.add(address);

     //Add rows to panel
     dataFields.add(firstRow);
     dataFields.add(secondRow);
     dataFields.add(thirdRow);
     dataFields.add(fourthRow);
     dataFields.add(fifthRow);
     dataFields.add(sixthRow);

     //Add buttons to panel
     buttonArea.add(newSticker);
     buttonArea.add(renewal);

     //Add panels to frame
     add(dataFields, BorderLayout.NORTH);
     add(buttonArea, BorderLayout.SOUTH);

     //Add functionality to buttons
     newSticker.addActionListener(this);
     renewal.addActionListener(this);

     //Open the file
     try
     {
        output = new DataOutputStream(new FileOutputStream("Sticker.dat"));
     }
     catch(IOException c)
     {
        System.exit(1);
     }

     //Construct window listener
     addWindowListener(
        new WindowAdapter()
           {
               public void windowClosing(WindowEvent e)
               {
                  System.exit(0);
               }
           }
      );
   }

   public void actionPerformed(ActionEvent e)
   {
      String arg = e.getActionCommand();
  String code;
  if (arg == "New Sticker")
     code = "N";
  else
     code = "R";

  if (
        (vin.getText().compareTo("")<1)       ||
        (year.getText().compareTo("")<1)      ||
        (make.getText().compareTo("")<1)      ||
        (model.getText().compareTo("")<1)     ||
        (firstName.getText().compareTo("")<1) ||
        (lastName.getText().compareTo("")<1)  ||
        (address.getText().compareTo("")<1)
     )
  {

     errorBox = new MessageBox(this, "Data Entry Error", "You must complete all fields.");
     errorBox.setVisible(true);
  }
  else
  {
  try
  {
     output.writeUTF(code);
     output.writeUTF(vin.getText());
     output.writeUTF(year.getText());
     output.writeUTF(make.getText());
     output.writeUTF(model.getText());
     output.writeUTF(firstName.getText());
     output.writeUTF(lastName.getText());
     output.writeUTF(address.getText());

         savedBox = new MessageBox(this, "Data Submitted", "The vehicle information has been saved.");
         savedBox.setVisible(true);
      }
      catch(IOException c)
      {
         System.exit(1);
      }
      clearFields();
      }
   }

   public void clearFields()
   {
      //Clear fields and reset the focus
      vin.setText("");
      year.setText("");
      make.setText("");
      model.setText("");
      firstName.setText("");
      lastName.setText("");
      address.setText("");
      vin.requestFocus();
    }
}

我知道他们希望原来的盒子被注释掉了，我想我做到了但是我不确定我是否已经得到了所有东西。感谢您提供的任何帮助。

Answer 1

指令声明“在涉及任何消息框的所有行的开头插入注释标记（//），但MessageBox声明语句”除外。您已注释掉所有Jlabels和JTextFields。我认为这不是教学的一部分。

您正在寻找所有saveBox和errorBox除声明MessageBox savedBox; MessageBox errorBox;

之外的所有内容

所以这些都是你想要评论的内容。

savedBox = new MessageBox(this, "Data Submitted", "The vehicle information has been saved.");
saveBox.setVisible(true);

errorBox = new MessageBox(this, "Data Entry Error", "You must complete all fields.");
errorBox.setVisible(true);

我相信你应该用JOptionPane

替换它们

JOptionPane.showInputDialog(null, "Data Entry Error", "You must complete all fields.");

植物城市贴纸joptionpane

1 个答案: