打开jdialog后更新jlabel文本 [英] update jlabel text after opening jdialog
问题描述
我必须查询数据库以获取要写入JLabel的数据并加速打开对话框
I have to query database to get data to write on JLabel and to accelerate opening dialog
我创建了没有文字的JLabel，并在执行SwingWorker程序后设置了文字
I have created JLabel with no text and set text after done a SwingWorker process
但JLabel文本不会更新
有什么办法可以实现这一目标
Is there any way to achieve this
这是我对话框的src代码:
Here is my dialog's src code:
package com.caisse.caisseFrame.dialogs;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.SwingWorker;
import com.caisse.ConnectDB;
import com.caisse.CustomComponent.JButtonCustom;
import com.caisse.CustomComponent.JPanelCustom;
import com.caisse.caisseFrame.CaisseFrame;
import com.soqop.caisse.dao.TicketDAO;
public class LectureXDialog extends JDialog {
/**
*
*/
private static final long serialVersionUID = 1L;
JButton ok_btn;
TicketDAO ticketDAO;
public LectureXDialog(final CaisseFrame parent) {
setAlwaysOnTop(true);
setSize(new Dimension(300, 280));
setLocationRelativeTo(parent);
setTitle("Lecture X");
setVisible(true);
setModalityType(ModalityType.DOCUMENT_MODAL);
parent.setEnabled(false);
ticketDAO = new TicketDAO(ConnectDB.getInstance());
final JPanelCustom componentsPanel = new JPanelCustom();
GridBagLayout componentsPanelLayout = new GridBagLayout();
componentsPanel.setLayout(componentsPanelLayout);
final JLabel lectureXlabel = new JLabel();
lectureXlabel.setFont(new Font("Cambria", Font.BOLD, 24));
lectureXlabel.setPreferredSize(new Dimension(250, 55));
lectureXlabel.setMinimumSize(new Dimension(250, 55));
GridBagConstraints gbc_lectureXlabel = new GridBagConstraints();
gbc_lectureXlabel.insets = new Insets(2, 2, 2, 2);
gbc_lectureXlabel.gridx = 0;
gbc_lectureXlabel.gridy = 0;
gbc_lectureXlabel.anchor = GridBagConstraints.CENTER;
componentsPanel.add(lectureXlabel, gbc_lectureXlabel);
ok_btn = new JButtonCustom("ok");
ok_btn.setFont(new Font("Cambria", Font.BOLD, 24));
try {
Image img = ImageIO.read(getClass().getResource("/resources/ok.png"));
ok_btn.setIcon(new ImageIcon(img));
} catch (IOException e1) {
e1.printStackTrace();
}
ok_btn.setPreferredSize(new Dimension(150, 55));
ok_btn.setMinimumSize(new Dimension(150, 55));
ok_btn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
parent.setEnabled(true);
parent.setFocus();
LectureXDialog.this.dispose();
}
});
GridBagConstraints gbc_ok_btn = new GridBagConstraints();
gbc_ok_btn.insets = new Insets(2, 2, 2, 2);
gbc_ok_btn.gridx = 0;
gbc_ok_btn.gridy = 1;
componentsPanel.add(ok_btn, gbc_ok_btn);
add(componentsPanel);
addWindowListener(new java.awt.event.WindowAdapter() {
@Override
public void windowClosing(java.awt.event.WindowEvent windowEvent) {
parent.setEnabled(true);
parent.setFocus();
LectureXDialog.this.dispose();
}
});
SwingWorker worker = new SwingWorker<Boolean, Void>() {
String text = "";
@Override
public Boolean doInBackground() {
text = "<html><center>Lecture X : " + ticketDAO.getLectureX() + "</center></html>";
return true;
}
@Override
public void done() {
lectureXlabel.setText(text);
lectureXlabel.revalidate();
lectureXlabel.repaint();
componentsPanel.revalidate();
componentsPanel.repaint();
getContentPane().revalidate();
getContentPane().repaint();
}
};
}
}
推荐答案
To make your Swing Worker to do the background work you need to call the SwingWorker#execute() method. If you don't add it, well... it won't know when to start working. It's like any other variable like:
JLabel label = new JLabel("Hello world");
但是，如果您从未将label添加到任何内容(或未添加到JButton的ActionListener)，则将永远不会添加/执行.
But if you never add that label to anything (or like an ActionListener not added to the JButton) it will never be added / executed.
worker.execute();
在构造函数内部或您希望其开始工作的任何地方.
Inside your constructor or wherever you want it to start working.
根据@MadProgrammer的评论:
As per @MadProgrammer's comment:
请记住，
SwingWorker可以返回数据，因此您可以返回String并在done方法中使用get来获取工作人员的返回，而不是返回Boolean，这在某种程度上更安全且更可用然后使用实例字段
Remember,
SwingWorkercan return data, so instead of returningBoolean, you could returnStringand usegetin thedonemethod to get the returns of the worker, somewhat safer and more usable then using an instance field
他指的是这样更改您工人的密码:
He refers to change your worker's code like this:
SwingWorker worker = new SwingWorker<Boolean, Void>() {
@Override
public String doInBackground() {
return "<html><center>Lecture X : " + ticketDAO.getLectureX() + "</center></html>";
}
@Override
public void done() {
lectureXlabel.setText(get());
lectureXlabel.revalidate();
lectureXlabel.repaint();
componentsPanel.revalidate();
componentsPanel.repaint();
getContentPane().revalidate();
getContentPane().repaint();
}
};
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