我正在使用 JFrame 为使用 mySQL 连接到数据库的 java 程序创建 GUI
我有 12 个 SQL 操作，我想为其创建 GUI
首先会要求输入1到12之间的数字，然后会进入12个开关盒
所以当我运行这个然后输入 1 然后确定 除非我最大化或更改窗口大小，否则更新按钮和文本字段不会显示
我看到了其他类似的问题，但我没有明白，所以如果你们可以提供示例代码!
import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
//import javax.swing.SwingConstants;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.sql.DriverManager;
import java.awt.event.ActionEvent;
import java.sql.*;
import java.awt.Color;
//import java.awt.FlowLayout;
import java.util.*;
import javax.swing.JToggleButton;
import javax.swing.JTextArea;
//import java.util.Date;
public class ProjectInterface extends JFrame {
static Scanner read = new Scanner(System.in);
static Connection connect = null;
static Statement statement = null;
static PreparedStatement preparedStatement = null;
static ResultSet resultSet = null;
static String uname;
static String aname;
static String res;
/**
*
*/
private static final long serialVersionUID = 1L;
private JPanel contentPane;
private JTextField ANtextField;
private JTextField c1textField;
private JTextField c11textField;
//private JLabel lblNewLabel;
//private JLabel lblNewLabel_1;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ProjectInterface frame = new ProjectInterface();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public ProjectInterface() {
setTitle("Database");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 378, 495);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
JPanel panel = new JPanel();
panel.setBackground(new Color(186, 85, 211));
panel.setForeground(new Color(0, 0, 0));
contentPane.add(panel, BorderLayout.CENTER);
panel.setLayout(null);
JLabel lblEnter = new JLabel("Enter 1-12");
lblEnter.setBounds(26, 8, 116, 14);
panel.add(lblEnter);
//RestextField.setHorizontalAlignment(SwingConstants.LEFT);
//label.setHorizontalAlignment(SwingConstants.LEFT);
ANtextField = new JTextField();
//panel.add(ANtextField);
ANtextField.setBounds(152, 5, 86, 20);
ANtextField.setColumns(10);
panel.add(ANtextField);
JButton btnOk = new JButton("OK");
btnOk.setBounds(248, 4, 63, 23);
panel.add(btnOk);
btnOk.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
/*
String uname;
String aname;
String res;*/
try {
/*
Connection connect = null;
Statement statement = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;*/
Class.forName("com.mysql.jdbc.Driver");
connect = DriverManager.getConnection("jdbc:mysql://localhost:3306/project?useSSL=false","root","R1234");
statement = connect.createStatement();
String s = ANtextField.getText();
int x = Integer.parseInt(s);
switch(x) {
//customer
case 1:
//update customer set Password = 999 where Username = 'Raghad';
//System.out.println(" (PK)");
JLabel lblc1 = new JLabel("Enter username you wish to update its password:");
lblc1.setBounds(30, 104, 300, 14);
panel.add(lblc1);
c1textField = new JTextField();
c1textField.setBounds(350, 104, 86, 20);
c1textField.setColumns(10);
panel.add(c1textField);
JLabel lblc11 = new JLabel("Enter new password:");
lblc11.setBounds(30, 140, 200, 14);
panel.add(lblc11);
c11textField = new JTextField();
c11textField.setBounds(350, 140, 86, 20);
c11textField.setColumns(10);
panel.add(c11textField);
JButton btnUpdate = new JButton("Update");
btnUpdate.setBounds(200, 200, 86, 20);
panel.add(btnUpdate);
btnUpdate.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
try {
preparedStatement = connect.prepareStatement("update customer set Password = ? where Username = ?");
preparedStatement.setString(1, c11textField.getText());
preparedStatement.setString(2, c1textField.getText());
preparedStatement.executeUpdate();
}catch(Exception e) {System.out.println("Exception in case1");}
}});
break;
case 2:
//update location
System.out.println("Enter username you wish to update its location (PK)");
uname = read.next(); //or nextLine?
System.out.println("Enter new city");
String city = read.nextLine();
System.out.println("Enter new street");
String st = read.nextLine();
System.out.println("Enter new ZIP code");
int zip = read.nextInt();
preparedStatement = connect.prepareStatement("update customer set City = ? where Username = ?");
preparedStatement.setString(1, city);
preparedStatement.setString(2, uname);
preparedStatement.executeUpdate();
preparedStatement = connect.prepareStatement("update customer set Street = ? where Username = ?");
preparedStatement.setString(1, st);
preparedStatement.setString(2, uname);
preparedStatement.executeUpdate();
preparedStatement = connect.prepareStatement("update customer set ZIPcode = ? where Username = ?");
preparedStatement.setInt(1, zip);
preparedStatement.setString(2, uname);
preparedStatement.executeUpdate();
break;
case 3:
//read or retrieve? customer info
JTextArea textArea_1 = new JTextArea();
textArea_1.setBounds(10, 78, 326, 357);
panel.add(textArea_1);
resultSet = statement.executeQuery("select * from customer ");
while(resultSet.next()) {
String username = resultSet.getString("Username");
String FName = resultSet.getString("FName");
String LName = resultSet.getString("LName");
int PhoneNo = resultSet.getInt("PhoneNo");
String Password = resultSet.getString("Password");
String Email = resultSet.getString("Email");
String City = resultSet.getString("City");
String Street = resultSet.getString("Street");
int ZIPcode = resultSet.getInt("ZIPcode");
String AName = resultSet.getString("AName");
//textArea_1.append("%10s %10s %10s %10s %10s %10s %10s\n","Username","FName","LName","PhoneNo","Password","Email","City","Street","ZIPcode","AName");
textArea_1.append("Username: " + username + "\n");
textArea_1.append("FName: " + FName + "\n");
textArea_1.append("LName: " + LName + "\n");
textArea_1.append("PhoneNo: " + PhoneNo + "\n");
textArea_1.append("Password: " + Password + "\n");
textArea_1.append("Email: " + Email + "\n");
textArea_1.append("City: " + City + "\n");
textArea_1.append("Street: " + Street + "\n");
textArea_1.append("ZIPcode: " + ZIPcode + "\n");
textArea_1.append("AName: " + AName + "\n\n");}
break;
case 4:
//delete
System.out.println("Enter the username you wish to delete its info (PK)");
String an = read.nextLine();
connect.prepareStatement("delete from customer where Username = " + "'" + an + "'").executeUpdate();
break;
// admin
case 5:
//update Responsibility
System.out.println("Enter admin name (PK");
aname = read.nextLine();
System.out.println("Enter new Responsibility");
res = read.nextLine();
preparedStatement = connect.prepareStatement("update admin set Responsibility = ? where AName = ?");
preparedStatement.setString(1, res);
preparedStatement.setString(2, aname);
preparedStatement.executeUpdate();
break;
case 6:
//delete customer from admin
System.out.println("Enter the admin name you wish to delete their customer (PK)");
aname = read.nextLine();
connect.prepareStatement("delete from customer where AName = " + "'" + aname + "'").executeUpdate();
break;
case 7:
//insert an admin
//read.next();
System.out.println("Enter admin name");
aname = read.nextLine();
System.out.println("Enter responsibility");
res = read.nextLine();
preparedStatement = connect.prepareStatement("insert into admin(AName,Responsibility) values(?,?)");
preparedStatement.setString(1,aname);
preparedStatement.setString(2,res);
preparedStatement.executeUpdate();
break;
case 8:
//retrieve first row admin name
resultSet = statement.executeQuery("select * from admin ");
if(resultSet.next()) {
aname = resultSet.getString("AName");
System.out.println("Username: " + aname + " ");}
break;
case 9:
//supplier
System.out.println("");
case 10:
}//switch
//JOptionPane.showMessageDialog(null, "");
}catch(Exception e) {
e.printStackTrace();
}
}
});
}
}
最佳答案
不要使用空布局。不要使用 setBounds(...)!
Swing 被设计为与布局管理器一起使用。当您动态地将组件添加到可见 GUI 时，基本代码是:
panel.add(....);
panel.revalidate();
panel.repaint();
revalidate() 将调用面板上的布局管理器，布局管理器将根据布局管理器的规则为每个组件指定大小/位置。
按照设计的方式使用 Swing。
关于java - JFrame 在窗口大小最大化之前不会更新，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47837496/