如何在點擊按鈕後顯示（添加）JTextArea？

Question

我想單擊按鈕CONNECT_BUTTON後顯示我的JTextArea。我該怎麼辦 ？此外，我試圖在我的JTextArea中添加一些網格，因爲我想用它來顯示數據庫中的一些記錄。任何想法如何做到這一點？

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

• 你必須設置適當的LayoutManager中要使用JLabel爲container（網格或FlowLayout中）

• 不使用NullLayout

• JTextArea ISN的情況下't指定爲容器刪除DATABASE_FIELD.setLayout(new GridLayout(3, 3));

• 使用JTextArea (10, 15)作爲INTIAL大小，而不是任意大小（當時有效JScrollPane太）

• 與JTextArea添加JScrollPane到JFrames CENTER area或更改JLabel小號佈局管理到BorderLayout，然後把JButtons到另一個單獨的JLabel（網格或的FlowLayout ）

---

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

setLocationRelativeTo(null); 
setDefaultCloseOperation(EXIT_ON_CLOSE); 
setVisible(true); 

• 搬完行代碼構造結束，然後取出驗證，作爲一邊要重新驗證（）和重繪（），監守你沒有停下的圖像重新繪製

• 通話pack()代替setSize

• See Initial Thread

• 唯一的可能的問題1quater，只是最重要的事情