本文介绍了将JTextArea插入带有JLabel的JPanel的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试显示我发布的图纸。当我的代码运行并且用户单击帐户时，面板仅显示确定和取消按钮（参见屏幕截图）。我已经为面板accountPanel添加了三个带有JLabel的JTextAreas，但是它们都没有显示。我的代码如下。
I am trying to display the drawing that I have posted. When my code runs and the user clicks Account, the panel only displays the buttons "OK" and "Cancel" (see screenshot). I have added three JTextAreas with a JLabel for each to the panel accountPanel but they don't display. My code is below.
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.Component;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.JRadioButton;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;
public class TestApplication implements ActionListener {
public static void main(String[] args) {
JLabel input = new JLabel();
final JFrame frame = new JFrame();
frame.setSize(1000, 1000);
frame.setTitle("RBA Test Application");
frame.add(input);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
JRadioButton apprve = new JRadioButton("Approve");
JRadioButton decline = new JRadioButton("Decline");
JRadioButton ethernet = new JRadioButton("Ethernet");
ethernet.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog esettings = new JDialog(frame);
esettings.setTitle("Ethernet Settings");
esettings.setSize(400, 400);
esettings.pack();
esettings.setVisible(true);
}
});
JRadioButton rs = new JRadioButton("RS232");
rs.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog rsettings = new JDialog(frame);
rsettings.setTitle("RS232 Settings");
rsettings.setSize(400, 400);
rsettings.pack();
rsettings.setVisible(true);
}
});
JRadioButton usbcdc = new JRadioButton("USB_CDC");
usbcdc.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog usbc = new JDialog(frame);
usbc.setTitle("USB_CDC Settings");
usbc.setSize(400, 400);
usbc.pack();
usbc.setVisible(true);
}
});
JRadioButton usbhid = new JRadioButton("USB_HID");
usbhid.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog usbh = new JDialog(frame);
usbh.setTitle("USB_HID Settings");
usbh.setSize(400, 400);
usbh.pack();
usbh.setVisible(true);
}
});
JButton next = new JButton("Next");
JButton aok = new JButton("OK");
JButton bok = new JButton("OK");
JButton cok = new JButton("OK");
JButton acancel = new JButton("Cancel");
JButton bcancel = new JButton("Cancel");
JButton ccancel = new JButton("Cancel");
JButton dcancel = new JButton("Cancel");
JLabel cardLabel = new JLabel("Card Number: ");
JLabel expLabel = new JLabel("Exp. Date: ");
JLabel cvvLabel = new JLabel("CVV: ");
JTextArea card = new JTextArea();
card.add(cardLabel);
JTextArea expDate = new JTextArea();
expDate.add(expLabel);
JTextArea cvv = new JTextArea();
cvv.add(cvvLabel);
final JPanel PortSettings = new JPanel();
PortSettings.add(ethernet);
PortSettings.add(rs);
PortSettings.add(usbcdc);
PortSettings.add(usbhid);
PortSettings.add(next);
PortSettings.add(bcancel);
final JPanel accountPanel = new JPanel();
accountPanel.add(bok);
accountPanel.add(ccancel);
accountPanel.add(card);
accountPanel.add(expDate);
accountPanel.add(cvv);
final JPanel apprvordecl = new JPanel();
apprvordecl.add(apprve);
apprvordecl.add(decline);
apprvordecl.add(aok);
apprvordecl.add(acancel);
final JPanel amountPanel = new JPanel();
amountPanel.add(cok);
amountPanel.add(dcancel);
input.setFont(new java.awt.Font("Tahoma", 3, 18));
input.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
input.setText("Input / Output Log");
JButton initialize = new JButton("Initialize");
JButton connect = new JButton("Connect");
JButton disconnect = new JButton("Disconnect");
JButton shutdown = new JButton("Shut Down");
JButton portsettings = new JButton("Port Settings");
portsettings.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog port = new JDialog(frame);
port.setTitle("Port Settings");
port.setSize(400, 400);
port.add(PortSettings);
port.pack();
port.setVisible(true);
}
});
JButton online = new JButton("Go Online");
JButton offline = new JButton("Go Offline");
JButton status = new JButton("Status");
JButton reboot = new JButton("Reboot");
JButton account = new JButton("Account");
account.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog accountDialog = new JDialog(frame);
accountDialog.setTitle("Account");
accountDialog.setSize(400, 400);
accountDialog.add(accountPanel);
accountDialog.pack();
accountDialog.setVisible(true);
}
});
JButton amount = new JButton("Amount");
amount.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog amount2 = new JDialog(frame);
amount2.setTitle("Amount");
amount2.setSize(400, 400);
amount2.add(amountPanel);
amount2.pack();
amount2.setVisible(true);
}
});
JButton reset = new JButton("Reset");
JButton approvordecl = new JButton("Approve / Decline");
approvordecl.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JDialog apprv = new JDialog(frame);
apprv.setTitle("Approve / Decline");
apprv.setSize(400, 400);
apprv.add(apprvordecl);
apprv.pack();
apprv.setVisible(true);
}
});
JButton test = new JButton("Test Button #1");
JButton testing = new JButton("Test Button #2");
JRadioButton button = new JRadioButton("Radio Button");
JRadioButton button2 = new JRadioButton("Radio Button");
JCheckBox checkbox = new JCheckBox("Check Box");
JCheckBox checkbox2 = new JCheckBox("Check Box");
ButtonGroup group = new ButtonGroup();
group.add(usbhid);
group.add(usbcdc);
group.add(ethernet);
group.add(rs);
ButtonGroup approvegroup = new ButtonGroup();
approvegroup.add(apprve);
approvegroup.add(decline);
JPanel testPanel = new JPanel();
testPanel.add(button);
testPanel.add(button2);
testPanel.add(checkbox2);
JPanel posPanel = new JPanel();
posPanel.add(test);
posPanel.add(testing);
posPanel.add(checkbox);
JPanel llpPanel = new JPanel();
llpPanel.add(online);
llpPanel.add(offline);
llpPanel.add(status);
llpPanel.add(reboot);
llpPanel.add(account);
llpPanel.add(amount);
llpPanel.add(reset);
llpPanel.add(approvordecl);
JPanel buttonPanel = new JPanel();
buttonPanel.add(initialize);
buttonPanel.add(connect);
buttonPanel.add(disconnect);
buttonPanel.add(shutdown);
buttonPanel.add(portsettings);
frame.add(buttonPanel);
frame.add(buttonPanel, BorderLayout.NORTH);
JTabbedPane tabbedPane = new JTabbedPane();
tabbedPane.addTab("LLP", null, llpPanel, "Low Level Protocol");
tabbedPane.addTab("POS",null, posPanel, "Point Of Sale");
tabbedPane.addTab("Test", null, testPanel, "Test");
JPanel tabsPanel = new JPanel(new BorderLayout());
tabsPanel.add(tabbedPane);
frame.add(tabsPanel, BorderLayout.CENTER);
frame.pack();
}
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
}
}
推荐答案
JPanel 使用 FlowLayout 默认情况下，它尊重首选尺寸。 JTextArea的的首选大小的默认宽度为 0 x 0 。您需要为 JTextComponent的提供首选大小才能显示。使用指定行和&列：
JPanel uses FlowLayout by default which respects preferred sizes. The default width of the preferred size for the JTextArea's is 0 x 0. You need to give the JTextComponent's a preferred size for them to appear. Use the constructor that specifys rows & columns:
JTextArea card = new JTextArea(5, 10);
别忘了制作 JTextArea 可以通过将其封装在 JScrollPane 中来滚动：
Don't forget to make the JTextArea scrollable by enclosing it in a JScrollPane:
accountPanel.add(new JScrollPane(card));
这篇关于将JTextArea插入带有JLabel的JPanel的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！