Java 杰拉贝尔没有露面
我试图在下一行中给出Java 杰拉贝尔没有露面,java,swing,Java,Swing,我试图在下一行中给出JLabel,但什么都没有发生,即使我运行代码时输出结果只显示空行: 主要类别: import javax.swing.JFrame; public class main { public static void main(String[] args){ test piyu=new test(); piyu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); piyu.se
JLabel
,但什么都没有发生,即使我运行代码时输出结果只显示空行:
主要类别:
import javax.swing.JFrame;
public class main {
public static void main(String[] args){
test piyu=new test();
piyu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
piyu.setSize(300,200);
piyu.setVisible(true);
}
}
测试等级:
import java.awt.*;
import javax.swing.*;
public class test extends JFrame {
private JLabel item1,item2;
public test() {
super("First Java app");
JPanel panel=new JPanel();
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
}
}
尝试将JPanel添加到JFrame,并观察其工作:)尝试将JPanel添加到JFrame,并观察其工作:)尝试将JPanel添加到JFrame,并观察其工作:)尝试将JPanel添加到JFrame,并观察其工作:)您只缺少一行。您从不将
JPanel
添加到JFrame
class test extends JFrame {
private JLabel item1,item2;
public test(){
super("First Java app");
JPanel panel=new JPanel();
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
this.add(panel);
}
}
另外,请注意,在这种情况下不需要扩展JFrame
。你也可以这样写:
import java.awt.*;
import javax.swing.*;
import javax.swing.JFrame;
public class main {
public static void main(String[] args){
JFrame piyu=new JFrame("First Java app");
JPanel panel=new JPanel();
JLabel item1,item2;
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
piyu.add(panel);
piyu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
piyu.setSize(300,200);
piyu.setVisible(true);
}
}
你只是少了一行。您从不将
JPanel
添加到JFrame
class test extends JFrame {
private JLabel item1,item2;
public test(){
super("First Java app");
JPanel panel=new JPanel();
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
this.add(panel);
}
}
另外,请注意,在这种情况下不需要扩展JFrame
。你也可以这样写:
import java.awt.*;
import javax.swing.*;
import javax.swing.JFrame;
public class main {
public static void main(String[] args){
JFrame piyu=new JFrame("First Java app");
JPanel panel=new JPanel();
JLabel item1,item2;
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
piyu.add(panel);
piyu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
piyu.setSize(300,200);
piyu.setVisible(true);
}
}
你只是少了一行。您从不将
JPanel
添加到JFrame
class test extends JFrame {
private JLabel item1,item2;
public test(){
super("First Java app");
JPanel panel=new JPanel();
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
this.add(panel);
}
}
另外,请注意,在这种情况下不需要扩展JFrame
。你也可以这样写:
import java.awt.*;
import javax.swing.*;
import javax.swing.JFrame;
public class main {
public static void main(String[] args){
JFrame piyu=new JFrame("First Java app");
JPanel panel=new JPanel();
JLabel item1,item2;
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
piyu.add(panel);
piyu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
piyu.setSize(300,200);
piyu.setVisible(true);
}
}
你只是少了一行。您从不将
JPanel
添加到JFrame
class test extends JFrame {
private JLabel item1,item2;
public test(){
super("First Java app");
JPanel panel=new JPanel();
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
this.add(panel);
}
}
另外,请注意,在这种情况下不需要扩展JFrame
。你也可以这样写:
import java.awt.*;
import javax.swing.*;
import javax.swing.JFrame;
public class main {
public static void main(String[] args){
JFrame piyu=new JFrame("First Java app");
JPanel panel=new JPanel();
JLabel item1,item2;
panel.setLayout(new GridLayout());
item1=new JLabel("MY NAME IS XYZ");
item2=new JLabel("YO");
item1.setToolTipText("GAME ON");
panel.add(item1);
panel.add(item2);
piyu.add(panel);
piyu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
piyu.setSize(300,200);
piyu.setVisible(true);
}
}