所以我一直在努力工作，学习用java编写，并且我已经接近可用的界面了，但我遇到了2个问题。当我尝试实现我覆盖了paint组件的CloudPanel时，它不会让我在该面板中设置gridbaglayout。为了尝试让其他一切工作，同时我弄清楚为什么我不能完成它，我创建了一个新的基本JPanel来填充表单。它几乎是正确的，但它迫使价格JTextField离开屏幕的一侧或者只是没有显示它，而它的标签位于它的中心而不是左边，因为它应该是。我在这里做错了什么线索？ **编辑**在我的应用程序中显示图像的2种方法试图实现，但都不起作用。 bLogin jPanel现在可以注释掉来测试另一种方法还没有工作，需要澄清setPreferredSize建议，当我将imageIcon grabbagconstraints的代码切换到现在显示的内容而不是相同的时候其余的，所有jlabels和jtextfields重叠。如果我删除了其他lGUI.add组件中不存在的所有行，那么它将恢复正常，除非没有图像加载，无论是作为标签还是背景。我在验证方面还有更多的工作要做（int为ID，我会说6个字符所以我可以选择我的限制来修改，而对于Price来说，我可以推断出我的浮动希望）。接下来的步骤？
package newprovider;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.*;
/*@Michael Christopher, author/owner */
public class NewProvider {
/** @param args the command line arguments*/
public static class CloudPanel extends JPanel {
//paint background
String backgroundPath="/images/CloudBack1.png";
@Override
public void paintComponent(Graphics cloud){
super.paintComponent(cloud);
Image back = new ImageIcon(getClass().getResource(backgroundPath)).getImage();
cloud.drawImage(back, 0,0, this);
}
}
public static void createGUI() {
//build main frame
JFrame mainFrame = new JFrame();
mainFrame.setTitle("New Provider Interface");
// mainFrame.setOpaque(false);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create the MenuBar - needs menu options
JMenuBar maintenanceMenuBar = new JMenuBar ();
maintenanceMenuBar.setOpaque(true);
maintenanceMenuBar.setBackground(new Color(176,224,230));
maintenanceMenuBar.setPreferredSize(new Dimension(500, 20));
//Create Logo
ImageIcon LogoBox = new ImageIcon("/images/CloudBack.png");
JLabel logoLabel = new JLabel(LogoBox);
//create variables
int addProviderCheck;
String[] options = {"Yes","No"};
String[] newExit = {"Exit", "New"};
Dimension d = new Dimension(400, 224);
//create labels and JTextFields
JLabel labelID = new JLabel ("New ProviderID");
final JTextField textID = new JTextField("providerID ", 20);
JLabel labelName = new JLabel ("New Provider Name");
final JTextField textName = new JTextField("Provider Name ", 20);
JLabel labelPrice = new JLabel ("New Provider Price");
final JTextField textPrice = new JTextField ("Price ", 20);
//make Submit, Clear, & Exit buttons
JButton submit = new JButton("Submit");
JButton clear = new JButton("Clear");
JButton exit = new JButton("Exit");
//build main Panel
CloudPanel bLogin = new CloudPanel();
bLogin.setPreferredSize(d);
//bLogin.setLayout(new GridBagLayout());
bLogin.setOpaque(true);
JPanel Login = new JPanel(new GridBagLayout());
JPanel buttonBar = new JPanel(new GridBagLayout());
buttonBar.setBackground(Color.red);
buttonBar.setSize(40, 400);
Login.setOpaque(false);
//GridBag constraints for buttonBar and InputPane4
GridBagConstraints bGUI = new GridBagConstraints();
//Adding buttons to buttonBar Panel
bGUI.insets = new Insets(5,20,5,20);
bGUI.gridx = 0;
bGUI.gridy = 1;
buttonBar.add(submit,bGUI);
bGUI.gridx = 1;
bGUI.gridy = 1;
buttonBar.add(clear,bGUI);
bGUI.gridx = 2;
bGUI.gridy = 1;
buttonBar.add(exit,bGUI);
//GridBag Adding Labels and Text to Login with Constraints
GridBagConstraints lGUI = new GridBagConstraints();
lGUI.insets = new Insets(50,15,0,0);
lGUI.anchor = GridBagConstraints.NORTH;
lGUI.fill = GridBagConstraints.BOTH;
lGUI.ipady = 100;
lGUI.weighty = 1.0;
lGUI.gridx = 0;
lGUI.gridwidth = 3;
lGUI.gridy = 0;
Login.add(logoLabel, lGUI);
lGUI.anchor = GridBagConstraints.WEST;
lGUI.gridx = 0;
lGUI.gridy = 1;
Login.add(labelID,lGUI);
lGUI.anchor = GridBagConstraints.EAST;
lGUI.gridx = 2;
lGUI.gridy = 1;
Login.add(textID,lGUI);
lGUI.anchor = GridBagConstraints.WEST;
lGUI.gridx = 0;
lGUI.gridy = 3;
Login.add(labelName,lGUI);
lGUI.anchor = GridBagConstraints.EAST;
lGUI.gridx = 2;
lGUI.gridy = 3;
Login.add(textName,lGUI);
lGUI.anchor = GridBagConstraints.WEST;
lGUI.gridx = 0;
lGUI.gridy = 5;
Login.add(labelPrice,lGUI);
lGUI.anchor = GridBagConstraints.EAST;
lGUI.gridx = 2;
lGUI.gridy = 5;
Login.add(textPrice,lGUI);
//add panels to frame
mainFrame.add(maintenanceMenuBar, BorderLayout.NORTH);
//bLogin.add(Login, BorderLayout.CENTER);
//mainFrame.add(bLogin, BorderLayout.CENTER);
mainFrame.add(Login, BorderLayout.CENTER);
mainFrame.add(buttonBar, BorderLayout.SOUTH);
SwingUtilities.invokeLater(new FocusGrabber(clear));
//empty fields on mouse clicks
textID.addMouseListener(new MouseListener() { @Override
public void mouseClicked(MouseEvent e) {textID.setText("");}
@Override public void mousePressed(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseReleased(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseEntered(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseExited(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
} } );
textName.addMouseListener(new MouseListener() { @Override
public void mouseClicked(MouseEvent e) {textName.setText("");}
@Override public void mousePressed(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseReleased(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseEntered(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseExited(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
} } );
textPrice.addMouseListener(new MouseListener() { @Override
public void mouseClicked(MouseEvent e) {textPrice.setText("");}
@Override public void mousePressed(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseReleased(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseEntered(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
}@Override public void mouseExited(MouseEvent e) { //throw new UnsupportedOperationException("Not supported yet.");
} } );
//focusListeners for Name Field
textName.addFocusListener(new FocusListener(){ @Override
public void focusGained(FocusEvent e) { /* throw new UnsupportedOperationException("Not supported yet.");*/ }
@Override public void focusLost(FocusEvent e) {
if (!e.isTemporary()) {
String checkName = textName.getText();
Boolean validName = false;
if (checkName.isEmpty()){JOptionPane.showMessageDialog(mainFrame, "Please enter a valid ID.");}
else while (validName = false){try {
String Name = textName.getText();
}catch (NumberFormatException e1){
JOptionPane.showMessageDialog(mainFrame, "Please enter a valid ID.");
SwingUtilities.invokeLater(new FocusGrabber(textName));
}finally {validName = true;}
} } } } );
//ActionListener for Submit button
submit.addActionListener((ActionEvent e) -> {
String Name;
Name = textName.getText();
int ID = Integer.parseInt(textID.getText());
double Price = Double.parseDouble(textPrice.getText());
int submitPress = JOptionPane.showOptionDialog(null,
"ProviderID: " + ID + "\n" + "Provider Name: " + Name +"\n"
+ "Provider Price: " + Price, "Please Verify Content",
JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE,
null, options,options[0]);
if (submitPress <= 0) {
//Store Displayed data
int providerID = ID;
String providerName = Name;
Double providerPrice = Price;
System.out.println(providerID);
System.out.println(providerName);
System.out.println(providerPrice);//add method to store println()s to database
//Popup Confirm dialog to reset fields or exit
int confirmNew = JOptionPane.showOptionDialog(null, "New Provider Confirmed\n" + "Would you like to exit the module or add another provider?", "Confirmation", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE, null, newExit, newExit[0]);
if (confirmNew <=0) {
mainFrame.setVisible(false);
mainFrame.dispose();
} else if (confirmNew > 0) {
textID.setText("providerID");
textName.setText("Provider Name");
textPrice.setText("Price");
} }
else if (submitPress > 0) {
textID.setText("providerID");
textName.setText("Provider Name");
textPrice.setText("Price"); }
});
//ActionListener for clear button
clear.addActionListener((ActionEvent e) -> {
textID.setText("providerID");
textName.setText("Provider Name");
textPrice.setText("Price");
});
//ActionListener for Exit Button
exit.addActionListener((ActionEvent e) -> {
mainFrame.setVisible(false);
mainFrame.dispose();
});
//verify intent to add new provider to system before continuing
addProviderCheck = JOptionPane.showOptionDialog(null,
"This will add a new service provider to the database.\n"
+ "Are you sure you wish to continue?",
"Please Verify Intent",JOptionPane.YES_NO_OPTION,JOptionPane.QUESTION_MESSAGE,null, options,options[0]);
if (addProviderCheck <= 0) {
//Display Window
mainFrame.pack();
mainFrame.setSize(400, 400);
mainFrame.setVisible(true);}
else { //else close app
mainFrame.setVisible(false);
mainFrame.dispose();
}
// mainFrame.setVisible(true);
}
public static void main(String[] args){
//draw and show the GUI
javax.swing.SwingUtilities.invokeLater(() -> {
createGUI();
});
//store new provider data
}
} Ive got it working (after manual resize) - well, the image as a logo is working, not the background. I've tried defining the size different places and none of them are changing it, it starts to small and once I resize it slightly wider and nearly twice as tall it then snaps to proper alignment. Here's the pieces I added:
mainFrame.setSize(new Dimension(800,425));
ImageIcon LogoBox = new ImageIcon("images/CloudBack.png");
JLabel logoLabel = new JLabel(LogoBox);
//create panel to stack logo and login
JPanel logFrame = new JPanel(new GridBagLayout());
logFrame.setOpaque(false); [....Unchanged code...]
JPanel Login = new JPanel(new GridBagLayout());
Login.setSize(800, 425);
JPanel buttonBar = new JPanel(new GridBagLayout());
buttonBar.setBackground(Color.red);
buttonBar.setSize(40, 400);
Login.setOpaque(false); [....Unchanged code....]
Login.add(textPrice,lGUI);
//GridBag Adding login and logo to panel
GridBagConstraints pGUI = new GridBagConstraints();
pGUI.insets = new Insets(5,10,15,20);
pGUI.anchor = GridBagConstraints.CENTER;
pGUI.fill = GridBagConstraints.BOTH;
pGUI.ipady = 400;
pGUI.weighty = 1.0;
pGUI.gridx = 0;
pGUI.gridy = 0;
logFrame.add(logoLabel, pGUI);
pGUI.anchor = GridBagConstraints.SOUTH;
pGUI.gridx = 0;
pGUI.gridy = 1;
logFrame.add(Login, pGUI); [....Unchanged Code....]
mainFrame.add(logFrame, BorderLayout.CENTER); [....Unchanged Code....]
答案 0 :(得分：0)
。当我尝试实现我覆盖了paint组件的CloudPanel时，它不会让我在该面板中设置gridbaglayout。
不确定你在问什么，但我注意到两个问题。
您创建了一个CloudPanel实例，但之后您永远不会对该实例执行任何操作。也就是说，您不要将面板添加到另一个面板或将任何组件添加到面板中。
您不能将CloudPanel类的getPreferredSize()方法覆盖为图像的大小。因此，大小将为（0,0），因此您无法将其添加到另一个面板。
此外，你不应该在绘画方法中使用I / O.只要Swing确定需要重新绘制组件并且您不想继续阅读图像，就会调用绘画方法。
答案 1 :(得分：0)
您的textPrice字段未显示，因为您没有将其添加到面板中，只需稍微更改一行代码，
lGUI.gridx = 0;
lGUI.gridy = 3;
Login.add(labelPrice,lGUI);
lGUI.gridx = 1;
lGUI.gridy = 3;
Login.add(textPrice,lGUI); <===== this one, you are adding labelPrice again