Java 为什么标签不显示在框架中？
在我的Java程序中，当调用按钮时，将显示一些标签和文本字段。但是，仅显示文本字段，当我使用鼠标减小或增大帧大小时，将显示标签 代码： 屏幕截图如下所示Java 为什么标签不显示在框架中？,java,swing,Java,Swing,在我的Java程序中，当调用按钮时，将显示一些标签和文本字段。但是，仅显示文本字段，当我使用鼠标减小或增大帧大小时，将显示标签 代码： 屏幕截图如下所示 我不能评论，所以我会回答的。 如果我是你，我会创建一个类似Label.java的类 创建一个包含所有必要数据的构造函数： private JLabel label; private Color fg; private Font font; private Rectangle rect; public Label(String name, Co
我不能评论，所以我会回答的。 如果我是你，我会创建一个类似Label.java的类 创建一个包含所有必要数据的构造函数：
private JLabel label;
private Color fg;
private Font font;
private Rectangle rect;
public Label(String name, Color foreground, Font font, Rectangle rect){
this.label = new JLabel(name);
this.label.setForeground(foreground);
this.label.setFont(font);
this.label.setBounds(rect);
}
ArrayList<Label> labels = new ArrayList<Label>();
labels.add(new Label("Name: ", Color.white, new Font("Serif", Font.BOLD, 15), new Rectangle(100, 100, 150, 20)));
labels.add(new Label("Mobile Number: ", Color.white, new Font("Serif", Font.BOLD, 15), new Rectangle(100, 150, 150, 20)));
/*.
.
.*/
ArrayList标签=新建ArrayList（）；
标签。添加（新标签（“名称：”，颜色。白色，新字体（“衬线”，字体。粗体，15），新矩形（100，100，150，20））；
标签。添加（新标签（“手机号码：”，颜色。白色，新字体（“衬线”，字体。粗体，15），新矩形（100，150，150，20））；
/*.
.
.*/
setLayout(new BorderLayout());
setContentPane(new JLabelnew ImageIcon(getClass().getResource("image.jpg"))));
首先在src文件夹中复制并粘贴背景图像，然后首先添加此背景代码，然后添加标签、按钮等。我建议您使用布局而不是边界可能问题在于没有为标签设置目标。您应该yse-
label.setLabelFor（target）l1= new JLabel("Name: ");
l1.setForeground(Color.white);
l1.setFont(new Font("Serif", Font.BOLD, 15));
l1.setBounds(100,100,150,20);
l1.setLabelFor(targetTextField)
1） 为了更快地获得更好的帮助，可以发布一个（最小完整的可验证示例）或（简短、自包含、正确的示例）。2） Java GUI必须在不同的操作系统、屏幕大小、屏幕分辨率等上工作，在不同的地区使用不同的PLAF。因此，它们不利于像素完美布局。改用版式管理器，或连同版式填充和边框一起使用。@Tanz Rahman请编辑您的答案并添加您的解决方案，也许这对某些人会有帮助。我会投票赞成你的答案：）
l1= new JLabel("Name: ");
l1.setForeground(Color.white);
l1.setFont(new Font("Serif", Font.BOLD, 15));
l1.setBounds(100,100,150,20);
l1.setLabelFor(targetTextField)
import javax.swing.*;
import java.util.Vector;
import java.sql.*;
import java.awt.event.*;
import java.awt.*;
import java.io.*;
import java.awt.image.*;
import javax.imageio.ImageIO;
public class Student_Database extends JFrame implements ActionListener {
private JTextField textfield, tf1, tf2, tf3, tf4, tf5, tf6, tf7, tf8, tf9, tf10, tf11, tf12, tf13, tf14,tf15;
private JLabel label,l1,l2,l3,l4,l5,l6,l7,l8,l9,l10,l11,l12,l13,l14,l15, l16, frame_imagelabel;
private JButton button, button2;
private ImageIcon frame_image, icon, icon1;
private Image img, myimg;
public Student_Database() {
setTitle("Student Information");
label= new JLabel("Enter Roll Number: ");
label.setForeground(Color.white);
label.setFont(new Font("Serif", Font.BOLD, 18));
label.setBounds(200,30,160,20);
textfield= new JTextField(6);
textfield.setBounds(370, 30, 100, 20);
button= new JButton ("OK");
button.setBounds(480, 30, 80, 20);
add(label);
add(textfield);
add(button);
button2=new JButton("CLICK for Main Menu");//creating instance of JButton
button2.setBounds(5,10,160,40);//x axis, y axis, width, height
add(button2);//adding button in JFrame
button2.setBackground(Color.white);
button2.setForeground(Color.black);
button2.addActionListener(this);
button.addActionListener(this);
frame_image= new ImageIcon ("F:/Java_program/Hostel_Management/Resource/images (1).jpg");
frame_imagelabel= new JLabel(frame_image);
frame_imagelabel.setBounds(0,0,1000, 700);
add(frame_imagelabel);
setSize(1000,700);//400 width and 600 height
setLayout(new BorderLayout());//using no layout managers
//getContentPane().setBackground(Color.white);
//pack();
//revalidate();
setVisible(true);//making the frame visible
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==button)
{
l1= new JLabel("Name: ");
l1.setForeground(Color.white);
l1.setFont(new Font("Serif", Font.BOLD, 15));
l1.setBounds(100,100,150,20);
//l1.setLabelFor(tf1);
l2= new JLabel("Mobile Number: ");
l2.setForeground(Color.white);
l2.setFont(new Font("Serif", Font.BOLD, 15));
l2.setBounds(100,150,150,20);
//l1.setLabelFor(tf2);
l3= new JLabel("Father's Name: ");
l3.setForeground(Color.white);
l3.setFont(new Font("Serif", Font.BOLD, 15));
l3.setBounds(100,200,150,20);
l4= new JLabel("Mobile Number: ");
l4.setForeground(Color.white);
l4.setFont(new Font("Serif", Font.BOLD, 15));
l4.setBounds(100,250,150,20);
l5= new JLabel("Mother's Name: ");
l5.setForeground(Color.white);
l5.setFont(new Font("Serif", Font.BOLD, 15));
l5.setBounds(100,300,150,20);
l6= new JLabel("Mobile Number: ");
l6.setForeground(Color.white);
l6.setFont(new Font("Serif", Font.BOLD, 15));
l6.setBounds(100,350,150,20);
l7= new JLabel("Village: ");
l7.setForeground(Color.white);
l7.setFont(new Font("Serif", Font.BOLD, 15));
l7.setBounds(100,400,150,20);
l8= new JLabel("Police Station: ");
l8.setForeground(Color.white);
l8.setFont(new Font("Serif", Font.BOLD, 15));
l8.setBounds(100,450,150,20);
l9= new JLabel("District: ");
l9.setForeground(Color.white);
l9.setFont(new Font("Serif", Font.BOLD, 15));
l9.setBounds(100,500,150,20);
l10= new JLabel("Blood Group: ");
l10.setForeground(Color.white);
l10.setFont(new Font("Serif", Font.BOLD, 15));
l10.setBounds(100,550,150,20);
l11= new JLabel("Department: ");
l11.setForeground(Color.white);
l11.setFont(new Font("Serif", Font.BOLD, 15));
l11.setBounds(600,100,150,20);
l12= new JLabel("Series: ");
l12.setForeground(Color.white);
l12.setFont(new Font("Serif", Font.BOLD, 15));
l12.setBounds(600,150,150,20);
l13= new JLabel("Roll Number: ");
l13.setForeground(Color.white);
l13.setFont(new Font("Serif", Font.BOLD, 15));
l13.setBounds(600,200,150,20);
l14= new JLabel("CGPA: ");
l14.setForeground(Color.white);
l14.setFont(new Font("Serif", Font.BOLD, 15));
l14.setBounds(600,250,150,20);
l15= new JLabel("Room Number: ");
l15.setForeground(Color.white);
l15.setFont(new Font("Serif", Font.BOLD, 15));
l15.setBounds(600,300,150,20);
tf1= new JTextField();
tf1.setBounds(300,100,200,20);
tf2= new JTextField();
tf2.setBounds(300,150,200,20);
tf3= new JTextField();
tf3.setBounds(300,200,200,20);
tf4= new JTextField();
tf4.setBounds(300,250,200,20);
tf5= new JTextField();
tf5.setBounds(300,300,200,20);
tf6= new JTextField();
tf6.setBounds(300,350,200,20);
tf7= new JTextField();
tf7.setBounds(300,400,200,20);
tf8= new JTextField();
tf8.setBounds(300,450,200,20);
tf9= new JTextField();
tf9.setBounds(300,500,200,20);
tf10= new JTextField();
tf10.setBounds(300,550,200,20);
tf11= new JTextField();
tf11.setBounds(710,100,200,20);
tf12= new JTextField();
tf12.setBounds(710,150,200,20);
tf13= new JTextField();
tf13.setBounds(710,200,200,20);
tf14= new JTextField();
tf14.setBounds(710,250,200,20);
tf15= new JTextField();
tf15.setBounds(710,300,200,20);
tf1.setEditable(false);
tf2.setEditable(false);
tf3.setEditable(false);
tf4.setEditable(false);
tf5.setEditable(false);
tf6.setEditable(false);
tf7.setEditable(false);
tf8.setEditable(false);
tf9.setEditable(false);
tf10.setEditable(false);
tf11.setEditable(false);
tf12.setEditable(false);
tf13.setEditable(false);
tf14.setEditable(false);
tf15.setEditable(false);
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con=DriverManager.getConnection(
"jdbc:mysql://localhost:3306/hostel_management","root","");
//here project is database name, root is username and password is empty
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select * from student_info where roll_no = '" + textfield.getText() + "'");
//if(rs.next()=null)
//JOptionPane.showMessageDialog(null, "No Available Seat. Please Select Another Room.", "Warning", JOptionPane.ERROR_MESSAGE);
int count= 0;
while(rs.next())
{
count++;
tf1.setText(rs.getString(1));
tf1.setHorizontalAlignment(JTextField.CENTER);
tf2.setText(rs.getString(2));
tf2.setHorizontalAlignment(JTextField.CENTER);
tf3.setText(rs.getString(3));
tf3.setHorizontalAlignment(JTextField.CENTER);
tf4.setText(rs.getString(4));
tf4.setHorizontalAlignment(JTextField.CENTER);
tf5.setText(rs.getString(5));
tf5.setHorizontalAlignment(JTextField.CENTER);
tf6.setText(rs.getString(6));
tf6.setHorizontalAlignment(JTextField.CENTER);
tf7.setText(rs.getString(7));
tf7.setHorizontalAlignment(JTextField.CENTER);
tf8.setText(rs.getString(8));
tf8.setHorizontalAlignment(JTextField.CENTER);
tf9.setText(rs.getString(9));
tf9.setHorizontalAlignment(JTextField.CENTER);
tf10.setText(rs.getString(10));
tf10.setHorizontalAlignment(JTextField.CENTER);
tf11.setText(rs.getString(11));
tf11.setHorizontalAlignment(JTextField.CENTER);
tf12.setText(rs.getString(12));
tf12.setHorizontalAlignment(JTextField.CENTER);
tf13.setText(rs.getString(13));
tf13.setHorizontalAlignment(JTextField.CENTER);
tf14.setText(rs.getString(14));
tf14.setHorizontalAlignment(JTextField.CENTER);
tf15.setText(rs.getString(15));
tf15.setHorizontalAlignment(JTextField.CENTER);
Blob blob = rs.getBlob("image");
int blobLength = (int) blob.length();
byte[] bytes = blob.getBytes(1, blobLength);
//blob.free();
BufferedImage image = ImageIO.read(new ByteArrayInputStream(bytes));
ImageIcon icon = new ImageIcon(bytes); // you can read straight from byte array
l16 = new JLabel(icon);
l16.setBounds(100, 100, 100, 50);
add(l16);
//add(frame_imagelabel);
add(l1);
add(tf1);
add(l2);
add(tf2);
add(l3);
add(tf3);
add(l4);
add(tf4);
add(l5);
add(tf5);
add(l6);
add(tf6);
add(l7);
add(tf7);
add(l8);
add(tf8);
add(l9);
add(tf9);
add(l10);
add(tf10);
add(l11);
add(tf11);
add(l12);
add(tf12);
add(l13);
add(tf13);
add(l14);
add(tf14);
add(l15);
add(tf15);
add(frame_imagelabel);
pack();
setSize(1000,700);
}
//if(im!=null)
//JOptionPane.showMessageDialog(null, "No image", "Warning", JOptionPane.ERROR_MESSAGE);
if(count==0)
JOptionPane.showMessageDialog(null, "This Student is not a member of this hall.", "Warning", JOptionPane.ERROR_MESSAGE);
con.close();
} catch(Exception ex){ JOptionPane.showMessageDialog(null, ex, "Error", JOptionPane.ERROR_MESSAGE); }
}
if(e.getSource()==button2)
{
project obj =new project();
dispose();
}
}
}