一次测试

src/main/java/com/example/Main.java

@@ -23,6 +23,7 @@ public class Main extends JFrame implements ActionListener {
         add(jb2);
         add(jb3);
         setBounds(100,100,500,500);
+        setLocationRelativeTo(null);
         setVisible(true);
     }
 

src/main/java/com/example/SalesProductManagement.java

@@ -1,4 +1,78 @@
 package com.example;
 
-public class SalesProductManagement {
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class SalesProductManagement extends JFrame implements ActionListener {
+
+    JButton btn1;
+    JLabel lab1,lab2,lab3,lab4,lab5,lab6,lab7;
+    JTextField text2,text3,text5,text6,text8,text9,text10;
+    //    JPasswordField passwordfile;
+    JPanel panel1,panel2,panel3;
+
+
+
+    SalesProductManagement(){
+        super("销售信息管理");
+        panel1 = new JPanel();
+        panel2 = new JPanel();
+        panel3 = new JPanel();
+        lab1=new JLabel("名称",JLabel.CENTER);
+        lab2=new JLabel("单价",JLabel.CENTER);
+        lab3=new JLabel("数量",JLabel.CENTER);
+        lab4=new JLabel("总计：",JLabel.CENTER);
+        lab5=new JLabel("苹果",JLabel.CENTER);
+        lab6=new JLabel("香蕉",JLabel.CENTER);
+        lab7=new JLabel("橘子",JLabel.CENTER);
+
+        text2=new JTextField("2"+"元",JTextField.CENTER);
+        text3=new JTextField(3);
+        text5=new JTextField("3"+"元",JTextField.CENTER);
+        text6=new JTextField(3);
+        text8=new JTextField("5"+"元",JTextField.CENTER);
+        text9=new JTextField(3);
+        text10=new JTextField(5);
+
+        btn1=new JButton("结算");
+
+
+        add(panel1);
+        panel1.setLayout(new GridLayout(1,3,5,5));
+        panel1.add(lab1);
+        panel1.add(lab2);
+        panel1.add(lab3);
+        panel1.setMaximumSize(new Dimension(Integer.MAX_VALUE, 40));
+        add(panel2);
+        panel2.setLayout(new GridLayout(3,3,5,5));
+        panel2.add(lab5);
+        panel2.add(text2);
+        panel2.add(text3);
+        panel2.add(lab6);
+        panel2.add(text5);
+        panel2.add(text6);
+        panel2.add(lab7);
+        panel2.add(text8);
+        panel2.add(text9);
+        panel2.setMaximumSize(new Dimension(Integer.MAX_VALUE, 120));
+        add(panel3);
+        panel3.setLayout(new GridLayout(1,3,5,5));
+        panel3.add(btn1);
+        panel3.add(lab4);
+        panel3.add(text10);
+        panel3.setMaximumSize(new Dimension(Integer.MAX_VALUE, 40));
+
+
+
+        setLayout(new GridLayout(3,1));
+        setSize(500,500);
+        setLocationRelativeTo(null);
+        setVisible(true);
+    }
+    @Override
+    public void actionPerformed(ActionEvent e) {
+
+    }
 }