【发布时间】：2015-07-28 21:43:08
【问题描述】：
我有一个奇怪的问题，我不知道是什么原因造成的。 我有一个对话框类，它只是在屏幕上显示错误/警告消息。有趣的是，当我设置窗口中心时，组件并没有出现（除非我重新调整它的大小）。
但是，当我更改屏幕位置时，JPanel 上会出现组件就好了。
我基本上把这条线改成int x = (dim.width - w) / 3;它就可以了。但是当宽度除以 2 时它不会。因此，对话框可以在除中心之外的任何地方工作。请让我知道我在这里缺少什么。
感谢您的帮助！
谢谢！
代码如下：
一个 MCVE：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
@SuppressWarnings("serial")
public class UKDialog extends JDialog {
private JButton button1;
private JLabel message;
public UKDialog(String message, String buttonText) {
this.button1 = new JButton(buttonText);
this.message = new JLabel(message);
setWarning();
}
public void setWarning() {
this.setModal(true);
this.setAlwaysOnTop(true);
if (this.message.getText().length() <= 30) {
this.setMaximumSize(new Dimension(650, 300));
this.setMinimumSize(new Dimension(650, 300));
this.setPreferredSize(new Dimension(650, 300));
} else if (this.message.getText().length() > 30) {
this.setMaximumSize(new Dimension(870, 300));
this.setMinimumSize(new Dimension(870, 300));
this.setPreferredSize(new Dimension(870, 300));
}
this.setLayout(new BorderLayout());
JPanel messagePanel = new JPanel();
messagePanel.setBorder(BorderFactory.createEtchedBorder());
JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
buttonPanel.setBorder(BorderFactory.createEtchedBorder());
buttonPanel.setPreferredSize(new Dimension(600, 100));
this.message.setFont(new Font("Calibri", Font.BOLD, 40));
this.button1.setPreferredSize(new Dimension(230, 80));
this.button1.setFont(new Font("Calibri", Font.BOLD, 45));
this.button1.setBackground(new java.awt.Color(139, 71, 137));
this.button1.setForeground(java.awt.Color.white);
this.button1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
okActionPerformed(evt);
}
});
messagePanel.add(this.message, BorderLayout.CENTER);
buttonPanel.add(this.button1);
this.add(messagePanel, BorderLayout.CENTER);
this.add(buttonPanel, BorderLayout.SOUTH);
// calculate the new location of the window
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
int w = this.getSize().width;
int h = this.getSize().height;
int x = (dim.width - w) / 2;
int y = (dim.height - h) / 5;
this.setLocation(x, y);
this.setVisible(true);
}
protected void okActionPerformed(ActionEvent evt) {
UKDialog.this.dispose();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
final JFrame frame = new JFrame("Main GUI");
JButton button = new JButton(new AbstractAction("Push Me") {
@Override
public void actionPerformed(ActionEvent e) {
String message = "Message is Long Enough???";
String buttonText = "Button";
UKDialog ukDialog = new UKDialog(message, buttonText);
}
});
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(500, 400));
panel.add(button);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
这是我的类用main方法调用警告类。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.ScrollPaneLayout;
import javax.swing.WindowConstants;
public class PAndDeliveryNotification extends JDialog {
private JButton button1;
private JLabel messageTitle;
private JTextField text;
private boolean reply;
private String typedText;
private ArrayList<String[]> remainingInvoices;
private String stopNum = null;
private String currentStopNum, lastStopNum;
public PAndDeliveryNotification(ArrayList<String[]> rInvoices, String buttonText1) {
this.button1 = new JButton(buttonText1);
this.remainingInvoices = rInvoices;
}
public void setDelivStopNo() throws IOException {
BufferedImage image = null;
try {
image = ImageIO.read(new File("images/uk.png"));
} catch (IOException e) {
}
this.setIconImage(image);
//frame properties
this.setModal(true);
this.setAlwaysOnTop(true);
this.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
this.setLayout(new BorderLayout());
//frame size
this.setPreferredSize(new Dimension(900, 600));
this.setMaximumSize(new Dimension(900, 600));
this.setMinimumSize(new Dimension(900, 600));
JPanel upperPanel = new JPanel(new WrapLayout());
upperPanel.setBorder(BorderFactory.createEtchedBorder());
for (int i = 0; i < this.remainingInvoices.size(); i++) {
String[] invoice;
invoice = (String[]) this.remainingInvoices.get(i);
if (i == 0) {
this.currentStopNum = invoice[0];
}
if (i == this.remainingInvoices.size() - 1) {
this.lastStopNum = invoice[0];
}
StopItem item = new StopItem(invoice);
item.setPreferredSize(new Dimension(770, 120));
upperPanel.add(item);
}
upperPanel.repaint();
upperPanel.revalidate();
JScrollPane pane = new JScrollPane(upperPanel);
pane.setPreferredSize(new Dimension(770, 600));
pane.getVerticalScrollBar().setPreferredSize(new Dimension(50, 0));
pane.setLayout(new ScrollPaneLayout());
this.add(pane, BorderLayout.CENTER);
JPanel lowerPanel = new JPanel(new BorderLayout());
lowerPanel.setBorder(BorderFactory.createEtchedBorder());
lowerPanel.setPreferredSize(new Dimension(600, 100));
JPanel messagePanel = new JPanel(new FlowLayout());
messagePanel.setPreferredSize(new Dimension(600, 80));
JPanel buttonPanel = new JPanel();
buttonPanel.setPreferredSize(new Dimension(240, 80));
this.messageTitle = new JLabel("Enter Delivery Stop Number:");
this.messageTitle.setFont(new Font("Calibri", Font.BOLD, 40));
this.messageTitle.setPreferredSize(new Dimension(480, 80));
this.text = new JTextField(3);
this.text.setPreferredSize(new Dimension(100, 80));
this.text.setFont(new Font("Calibri", Font.BOLD, 40));
this.text.setHorizontalAlignment(JTextField.CENTER);
this.text.requestFocus();
Runtime.getRuntime().exec("cmd /c tabtip.exe");
this.button1.setPreferredSize(new Dimension(230, 80));
this.button1.setFont(new Font("Calibri", Font.BOLD, 45));
this.button1.setBackground(new java.awt.Color(139, 71, 137));
this.button1.setForeground(java.awt.Color.white);
this.button1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
saveStopNumActionPerformed(evt);
}
});
messagePanel.add(this.messageTitle);
messagePanel.add(this.text);
buttonPanel.add(this.button1);
lowerPanel.add(messagePanel, BorderLayout.WEST);
lowerPanel.add(buttonPanel, BorderLayout.EAST);
this.add(pane, BorderLayout.CENTER);
this.add(lowerPanel, BorderLayout.SOUTH);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
// calculate the new location of the window
int w = this.getSize().width;
int h = this.getSize().height;
int x = (dim.width - w) / 2;
int y = 0;
this.setLocation(x, y);
this.setVisible(true);
}
private void saveStopNumActionPerformed(ActionEvent evt) {
this.stopNum = this.text.getText();
try {
if (stopNum == null) {
new UKDialog("Fields cannot be empty!", "OK");
return;
} else if (Integer.parseInt(stopNum) < Integer.parseInt(this.currentStopNum)) {
new UKDialog("Delivery cannot be before pick up!", "OK");
return;
} else if (Integer.parseInt(stopNum) > Integer.parseInt(this.lastStopNum) + 1) {
new UKDialog("Enter stop number between " + this.currentStopNum + 1 + " and "
+ this.lastStopNum, "OK");
return;
}
} catch (NumberFormatException e) {
new UKDialog("Please enter numeric values!", "OK");
return;
}
System.out.println(this.stopNum);
this.setVisible(false);
this.dispose();
}
public String getStopNum() {
return this.stopNum;
}
private class StopItem extends JPanel {
private JPanel numPanel = new JPanel();
private JLabel itemNumber = new JLabel();
private JPanel leftPanel = new JPanel();
private JLabel invNoLbl = new JLabel();
private JLabel consigneeLbl = new JLabel();
private JLabel locationLbl = new JLabel();
private final String pUStopNo;
private final String invoiceNo;
private final String consignee;
private final String location;
public StopItem(String[] invoice) {
this.pUStopNo = invoice[0];
this.invoiceNo = invoice[1];
this.consignee = invoice[2];
this.location = invoice[3];
//Left and numberpanels
this.numPanel.setLayout(new BorderLayout());
this.numPanel.setPreferredSize(new Dimension(80, 80));
this.leftPanel.setLayout(new BorderLayout());
this.leftPanel.setPreferredSize(new Dimension(200, 90));
//number panel
this.itemNumber.setFont(new java.awt.Font("Lucida Grande", Font.BOLD, 45));
this.itemNumber.setText(String.valueOf(" " + pUStopNo));
//this.numPanel.setBorder(BorderFactory.createEtchedBorder());
this.numPanel.add(this.itemNumber);
//Main panel
this.setLayout(new BorderLayout());
this.setBorder(BorderFactory.createLineBorder(Color.black, 2));
this.invNoLbl.setText("Invoice #: " + this.invoiceNo);
this.invNoLbl.setFont(new java.awt.Font("Calibri", Font.PLAIN, 35));
this.consigneeLbl.setText("Consignee: " + this.consignee);
this.consigneeLbl.setFont(new java.awt.Font("Calibri", Font.PLAIN, 35));
this.locationLbl.setText("Location: " + this.location);
this.locationLbl.setFont(new java.awt.Font("Calibri", Font.PLAIN, 35));
this.leftPanel.add(this.invNoLbl, BorderLayout.NORTH);
this.leftPanel.add(this.consigneeLbl, BorderLayout.CENTER);
this.leftPanel.add(this.locationLbl, BorderLayout.SOUTH);
// add all the components to the frame
this.add(this.numPanel, BorderLayout.WEST);
this.add(this.leftPanel, BorderLayout.CENTER);
}
}
public static void main(String[] args) throws IOException {
String[] array1 = {"6", "444555", "Ali Murtaza Sumer", "Carson, Ca 90746"};
String[] array2 = {"7", "444666", "Hasan Huseyin Karabiber", "Los Angeles, Ca 90746"};
String[] array3 = {"8", "444777", "Mustafa Tinaztepe", "Macomb, IL 61455"};
String[] array4 = {"9", "444888", "Berkay Surmeli", "Chicago, IL 60625"};
String[] array5 = {"6", "444555", "Ali Murtaza Sumer", "Carson, Ca 90746"};
String[] array6 = {"7", "444666", "Hasan Huseyin Karabiber", "Los Angeles, Ca 90746"};
String[] array7 = {"8", "444777", "Mustafa Tinaztepe", "Macomb, IL 61455"};
String[] array8 = {"9", "444888", "Berkay Surmeli", "Chicago, IL 60625"};
ArrayList<String[]> aL = new ArrayList<>();
aL.add(array1);
aL.add(array2);
aL.add(array3);
aL.add(array4);
PAndDeliveryNotification question = new PAndDeliveryNotification(aL, "SAVE");
question.setDelivStopNo();
}
}
【问题讨论】：
-
请阅读minimal reproducible example 链接以确切了解我们要求的是什么以及为什么。此外，您应该避免设置组件大小或边界。而是在你的对话框上调用
pack()，调用上面提到的每个@LuxxMiner 的方法，你的对话框的大小应该正确并居中。 -
什么时候设置Dialog的值？也许有一个 repaint() 问题。尝试在显示对话框之前设置值。
-
生气了？一个简单的单行请求的有趣解释。但说真的，请阅读链接以了解我们需要什么——一个我们可以实际编译和运行的小程序，它可以重现您的问题。发布此内容，我们将快速了解您的问题，因此我们可能会为您提供快速有效的帮助。没有你的代码不是“完整的”。我不能将它粘贴到我的 IDE 中并编译或运行它，可以吗？而且我并不是想“教”你任何东西。我和其他人一样——我试图更好地理解你的问题，仅此而已。
-
好的，我明白我的问题不完整。老实说，我以为您在谈论我应该使用最少的代码并直截了当。这就是我删除该方法并留下有问题的代码行的原因。我为此道歉。现在，我认为我的问题已经完成，如果您将其复制并粘贴到您的 IDE 中，它应该可以工作。 @HovercraftFullOfEels