Question

我想在点击按钮CONNECT_BUTTON后显示我的JTextArea。我该怎么办？此外，我正在尝试在我的JTextArea中添加一些网格，因为我想用它来显示数据库中的一些记录。任何想法如何做到这一点？

package DataBase_Hospital;      

import java.awt.BorderLayout;
import java.awt.FlowLayout;          
import java.awt.GridLayout;      
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;


public class test extends JFrame implements ActionListener {



private JButton FIND_BUTTON;
private JButton MESSAGE_BUTTON;
private JButton CONNECT_BUTTON;
private JButton CLEAR_BUTTON;
private JButton ADD_BUTTON;
private JButton RAPORT_BUTTON;
private JButton EDIT_BUTTON;
private JButton DOWNLOAD_BUTTON;

private JTextArea DATABASE_FIELD;

private DatabaseManagement DATABASE;



public test(){

setTitle("Hospital Management");
setSize(900,600);

setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
JLabel background=new JLabel(new ImageIcon("/Users/Dominik/Desktop/j.jpg"));
add(background);

DATABASE_FIELD = new JTextArea();
JScrollPane scrollPane = new JScrollPane(DATABASE_FIELD);
scrollPane.setBounds(50, 50, 800, 400);
background.add(scrollPane);
DATABASE_FIELD.setEditable(true);
DATABASE_FIELD.setLayout(new GridLayout(3, 3));
//DATABASE_FIELD.setVisible(false);

CONNECT_BUTTON = new JButton();
CONNECT_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/connect_no.png"));
CONNECT_BUTTON.setBounds(165, 500, 60, 60);
background.add(CONNECT_BUTTON);
CONNECT_BUTTON.addActionListener(this);
CONNECT_BUTTON.setToolTipText("Connect to Data Base");

FIND_BUTTON = new JButton();
FIND_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/search.png"));
FIND_BUTTON.setBounds(240, 500, 60, 60);
background.add(FIND_BUTTON);
FIND_BUTTON.addActionListener(this);
FIND_BUTTON.setToolTipText("Find record in Data Base");


ADD_BUTTON = new JButton();
ADD_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/user_add.png"));
ADD_BUTTON.setBounds(315, 500, 60, 60);
background.add(ADD_BUTTON);
ADD_BUTTON.addActionListener(this);
ADD_BUTTON.setToolTipText("Add record to Data Base");


RAPORT_BUTTON = new JButton();
RAPORT_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/raport.png"));
RAPORT_BUTTON.setBounds(392, 500, 60, 60);
background.add(RAPORT_BUTTON);
RAPORT_BUTTON.addActionListener(this);
RAPORT_BUTTON.setToolTipText("Generates raport");

EDIT_BUTTON = new JButton();
EDIT_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/user_edit.png"));
EDIT_BUTTON.setBounds(467, 500, 60, 60);
background.add(EDIT_BUTTON);
EDIT_BUTTON.addActionListener(this);
EDIT_BUTTON.setToolTipText("Edit record from Data Base");

CLEAR_BUTTON = new JButton();
CLEAR_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/delete.png"));
CLEAR_BUTTON.setBounds(544, 500, 60, 60);
background.add(CLEAR_BUTTON);
CLEAR_BUTTON.addActionListener(this);
CLEAR_BUTTON.setToolTipText("Clear all Data Base");

MESSAGE_BUTTON = new JButton();
MESSAGE_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/message.png"));
MESSAGE_BUTTON.setBounds(619, 500, 60, 60);
background.add(MESSAGE_BUTTON);
MESSAGE_BUTTON.addActionListener(this);
MESSAGE_BUTTON.setToolTipText("Send message to another user");

DOWNLOAD_BUTTON = new JButton();
DOWNLOAD_BUTTON.setIcon(new ImageIcon("/Users/Dominik/Desktop/download.png"));
DOWNLOAD_BUTTON.setBounds(694, 500, 60, 60);
background.add(DOWNLOAD_BUTTON);
DOWNLOAD_BUTTON.addActionListener(this);
DOWNLOAD_BUTTON.setToolTipText("Download Data Base to a text file");


validate();
}


public static void main(String[] args) {
// TODO Auto-generated method stub
test window = new test();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);


}

@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub

Object EVENT_SOURCE = e.getSource();
DATABASE = new DatabaseManagement();


if (EVENT_SOURCE == CLEAR_BUTTON) 
{
    System.out.println("siema");

}   
else if (EVENT_SOURCE == DOWNLOAD_BUTTON)
{
    dispose();
}
else if (EVENT_SOURCE == CONNECT_BUTTON) 
{
    DATABASE_FIELD.setText("");
      //**           TRZEBA ZROBIC SIATKE !!!                    **//
    DATABASE_FIELD.append("IMIE ");
    DATABASE_FIELD.append("NAZWISKO ");
    DATABASE_FIELD.append("PESEL  \n");
    DATABASE_FIELD.append(DATABASE.showDataBase());
}

    }

}

Answer 1

如果您要将LayoutManager用作JLabel（网格或FlowLayout），则必须设置正确的container
不要使用NullLayout
JTextArea未指定为容器移除DATABASE_FIELD.setLayout(new GridLayout(3, 3));
使用JTextArea (10, 15)作为初始大小而不是任何大小调整（然后对JScrollPane也有效）
将JScrollPane与JTextArea添加到JFrames CENTER area或将JLabel的LayoutManager更改为BorderLayout，然后将JButtons添加到JLabel另一个单独的setTitle("Hospital Management"); setSize(900,600); setLocationRelativeTo(null); setDefaultCloseOperation(EXIT_ON_CLOSE); setVisible(true);（网格或FlowLayout）

pack()

将这些代码行移动到构造函数的末尾，然后删除validate，另外应该是revalidate（）和repaint（），因为你没有为图像重新绘制而停止
致电setSize而非{{1}}
See Initial Thread
只有一个可能的问题，只是最重要的事情

按钮点击后如何显示（添加）JTextArea？

1 个答案: