【发布时间】:2017-05-17 11:58:15
【问题描述】:
我这里有两个动作。一个是查看学生信息,第二个是查看教师信息。
我想添加学生和老师这两个标签,但是不知道在java的自定义布局中在哪里添加jpanels。
请帮助我提出解决方案或指出要添加的格式。
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.sql.*;
public class Searchdb extends JFrame implements ActionListener {
//Initializing Components
JLabel lb,lbd,lb1, lb2, lb3, lb5;
JTextField tf1, tf2,tf3,tf5,tfd;
JButton btn;
//Creating Constructor for initializing JFrame components
Searchdb() {
//Providing Title
super("Fetching Roll Information");
lb5 = new JLabel("Roll Number:");
lb5.setBounds(20, 20, 100, 20);
tf5 = new JTextField(20);
tf5.setBounds(130, 20, 200, 20);
lbd = new JLabel("Date:");
lbd.setBounds(20, 50, 100, 20);
tfd = new JTextField(20);
tfd.setBounds(130, 50, 200, 20);
btn = new JButton("Submit");
btn.setBounds(50, 50, 100, 20);
btn.addActionListener(this);
lb = new JLabel("Fetching Student Information From Database");
lb.setBounds(30, 80, 450, 30);
lb.setForeground(Color.black);
lb.setFont(new Font("Serif", Font.PLAIN, 12));
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 500);
lb1 = new JLabel("Name:");
lb1.setBounds(20, 120, 100, 20);
tf1 = new JTextField(50);
tf1.setBounds(130, 120, 200, 20);
lb2 = new JLabel("Fathername:");
lb2.setBounds(20, 150, 100, 20);
tf2 = new JTextField(100);
tf2.setBounds(130, 150, 200, 20);
lb3 = new JLabel("State:");
lb3.setBounds(20, 180, 100, 20);
tf3 = new JTextField(50);
tf3.setBounds(130, 180, 200, 20);
setLayout(null);
//Add components to the JFrame
add(lb5);
add(tf5);
add(lbd);
add(tfd);
add(btn);
add(lb);
add(lb1);
add(tf1);
add(lb2);
add(tf2);
add(lb3);
add(tf3);
//Set TextField Editable False
tf1.setEditable(false);
tf2.setEditable(false);
tf3.setEditable(false);
}
public void actionPerformed(ActionEvent e) {
//Create DataBase Coonection and Fetching Records
// First panel dispalyed only the student below information.
try {
String str = tf5.getText();
Datestri = tfd.getText();//Getting the unable to convert String to Date error
System.out.println(str);
System.out.println(stri);
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con = DriverManager.getConnection("jdbc:oracle:thin:@//host:port/servicename","username","password");
PreparedStatement st = con.prepareStatement("select Name,Fathername,State from student_db where roll_number=? and medium=?");
System.out.println(st);
st.setString(1, str);
st.setDate(2, stri);
//Excuting Query
ResultSet rs = st.executeQuery();
System.out.println(rs);
if (rs.next()) {
String s = rs.getString(1);
String s1 = rs.getString(2);
String s2 = rs.getString(3);
//Sets Records in TextFields.
tf1.setText(s);
tf2.setText(s1);
tf3.setText(s2);
} else {
JOptionPane.showMessageDialog(null, "Student not Found");
}
//Create Exception Handler
} catch (Exception ex) {
System.out.println(ex);
}
}
public void actionPerformed(ActionEvent e) {
//Create DataBase Coonection and Fetching Records
// Second panel dispalyed only the teacher information.
//Teacher information should be retrieved from the db
}
//Running Constructor
public static void main(String args[]) {
new Searchdb();
}
}
提前感谢您的帮助。
【问题讨论】:
-
Java GUI 必须在不同的操作系统、屏幕尺寸、屏幕分辨率等上使用不同的语言环境中的不同 PLAF。因此,它们不利于像素完美布局。而是使用布局管理器,或 combinations of them 以及 white space 的布局填充和边框。
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我认为布局管理器不是最佳实践,这就是为什么尝试自定义布局并且每次选择和使用哪个布局管理器时都会感到困惑?@AndrewThompson
-
以最小尺寸提供 ASCII 艺术或简单的 GUI 绘图,如果可调整大小,则提供更多宽度和高度(以显示如何分配额外空间)。如果学生/教师容器有不同的布局,则显示两倍的 ASCII 艺术/绘图(每个一个)。
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太好了,我一定会尝试@Andrew Thompson
标签: java swing user-interface layout