java - 尝试向另一个类中的 GUI 显示 HashMap 值

Question

问题是这样的: 我想检查我的所有客户名单。因此，我将使用 HashMap 并输出它们的 ic 编号和名称。如果我尝试使用终端，输出运行正常。

但现在我想将这些 HashMap 的结果输出到 GUI 中

这是到目前为止我的编码。您可以直接跳到 viewNumCust 的操作事件。这就是我尝试将 haspmap 输出到 jtextarea 的地方。

import javax.swing.*;
import java.io.*;
import java.util.*;

import java.awt.*;
import java.awt.event.*;
import java.io.FileReader;
import java.util.HashMap;
import java.util.Scanner;
import java.util.StringTokenizer;

public class manageClientAccGui extends JFrame
{
ImageIcon image;
JLabel imgLabel,clientLabel,helloLabel,greetingLabel;
JButton createCustProfileButt,editClientAccButt,deleteClientButt,backClientButt,viewNumCust;
JPanel panel1,panel2,panel3,panel4,panel5,panel6,panel7;
JTextArea viewListCust;

public manageClientAccGui()
{

    super("Team Garoking Manage Customer");

    Container con = getContentPane();
    con.setLayout(new BorderLayout());

    image = new ImageIcon("images/garokingLogo.jpg");
    imgLabel = new JLabel(image);

    clientLabel = new JLabel("Manage Client Account");
    clientLabel.setForeground(Color.WHITE);

    helloLabel = new JLabel("Hello! ");
    helloLabel.setForeground(Color.WHITE);

    greetingLabel = new JLabel("What would you like to do? ");
    greetingLabel.setForeground(Color.WHITE);

    JScrollPane scrollPane = new JScrollPane(viewListCust,
            JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
            JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
    scrollPane.setPreferredSize(new Dimension(100, 100));

    JLabel empty = new JLabel("");
    JLabel empty1 = new JLabel("");
    JLabel empty2 = new JLabel("");
    JLabel empty3 = new JLabel("");
    JLabel empty4 = new JLabel("");

    createCustProfileButt = new JButton("Create Customer");
    editClientAccButt = new JButton("Edit Customer Details");
    deleteClientButt = new JButton("Remove Customer");
    viewNumCust = new JButton("View Number of Customers");
    backClientButt = new JButton("Back");
    viewListCust = new JTextArea();
    viewListCust.setEditable(false);

    panel1 = new JPanel();
    panel2 = new JPanel(new GridLayout(12,3));
    panel3 = new JPanel(new GridLayout(12,3,0,3));
    panel4 = new JPanel();
    panel5 = new JPanel();

    panel6 = new JPanel(new GridLayout(1,2));
    panel7 = new JPanel(new GridLayout(1,2));

    panel1.add(imgLabel);
    panel1.setBackground(new Color(90,18,18));

    panel2.add(clientLabel);
    panel2.add(empty);
    panel2.add(createCustProfileButt);
    panel2.add(empty1);
    panel2.add(editClientAccButt);
    panel2.add(empty2);
    panel2.add(deleteClientButt);
    panel2.add(empty3);
    panel2.add(viewNumCust);    
    panel2.add(empty4);
    panel2.add(backClientButt);
    panel2.setBackground(new Color(90,18,18));

    panel6.add(helloLabel);
    panel6.setBackground(new Color(90,18,18));

    panel7.add(greetingLabel);
    panel7.setBackground(new Color(90,18,18));

    panel3.add(panel6);
    panel3.add(panel7);
    panel3.setBackground(new Color(90,18,18));
    panel3.add(scrollPane);

    panel5.add(panel3);
    panel5.setBackground(new Color(90,18,18));

    panel4.add(panel2);
    panel4.setBackground(new Color(90,18,18));

    con.add(panel4, BorderLayout.WEST);
    con.add(panel1, BorderLayout.NORTH);
    con.add(panel5, BorderLayout.CENTER);

    Action act = new Action();

    createCustProfileButt.addActionListener(act);
    editClientAccButt.addActionListener(act);
    deleteClientButt.addActionListener(act);
    backClientButt.addActionListener(act);
    viewNumCust.addActionListener(act);

    setVisible(true);
    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
    setLocation(((dim.width-1024)/2), ((dim.height-650)/2));
    setSize(1024,650);

}

//  public static void main(String args[])
//  {
//      new manageClientAccGui();
//  }

class Action implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {   
            if(e.getSource() == createCustProfileButt)
            {
                dispose();
                new Log("Accessing create customer");
                new addCustGui();
            }

            if(e.getSource() == editClientAccButt)
            {
                dispose();
                new Log("Accessing edit customer");
                new editCustGui();
            }

            if(e.getSource() == deleteClientButt)
            {
                dispose();
                new Log("Accessing remove customer");
                new removeCustGui();
            }

            if(e.getSource() == backClientButt)
            {
                dispose();
                new Log("Accessing main menu");
                new menuGarokingGui();
            }

            if(e.getSource() == viewNumCust)
            {
                int enumer = 0;
                HashMap<String, String> map = new HashMap<String, String>();

                try
                {
                    Scanner scanner = new Scanner(new FileReader("IndividualDetails.txt"));

                    while (scanner.hasNextLine()) {
                        String[] columns = scanner.nextLine().split("\t");
                        map.put(columns[1,], columns[2])
                        enumer++;
                    }
                }catch (FileNotFoundException ex)
                    {
                    }
                    new Log("View latest");
                    viewListCust.append("The clients are : " + map.values());
                    viewListCust.append("The total number of clients are : " + enumer);         
            }
        }
    }
}

Answer 1

Map#values 返回对象的Collection。

调用 viewListCust.append("Theclients are : "+ map.values()) 只是调用返回集合的 Collection#toString 方法，这不太可能提供内容的漂亮 View 。

相反，您必须自己迭代该集合。

viewListCust.append("The clients are :");
for (String value : map.values()) {
    viewListCust.append("\n" + value);
}

现在请记住，当您读取文件并附加内容时，您正在阻塞事件调度线程，这将使您的程序看起来像是挂起的。

您可能希望在更新 UI 之前利用 SwingWorker 在后台加载文件。查看Concurrency in Swing