Java GridBagLayout 组件未全屏显示

Question

我是 Java 的新手，正在尝试使用 GridBagLayout 生成我的第一个 GUI。使用下面的代码，我可以全屏显示，但组件 "label_url_eingabe" 和 "url_eingabe" 未显示（空 window）。当我最小化 window 时，它们会显示出来！当我将 window 大小设置为特定值时，我得到了相同的行为。所以这些组件在我的程序最初启动时没有显示。

package ofb_reader_package;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

public class OFB_Reader_GUI extends JFrame {

// Definition der GUI Komponenten

    // Eingabefeld URL

    JLabel label_url_eingabe;
    JTextField url_eingabe;

    //this.OFB_Reader_GUI();

// Eigenschaften Hauptfenster "OFB_Reader_GUI"  
    public OFB_Reader_GUI() {

        // Eigenschaften Hauptfenster   
        setVisible(true);
        setSize(500, 300);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
        setTitle("Mark's OFB Reader");
        setResizable(true);
        setExtendedState(JFrame.MAXIMIZED_BOTH); 
        setLayout(null);




        this.label_url_eingabe = new JLabel("URL:");
        this.url_eingabe = new JTextField(10);

        this.getContentPane().setLayout(new GridBagLayout());
        GridBagConstraints c = new GridBagConstraints();


        // POSITIONIERUNGEN MIT GRIDBAGLAYOUT

        // URL Eingabe Label und Einghabefeld 
        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 0;
        c.gridy = 0;
        c.ipadx = 35;
        c.weightx = 1.0;
        c.weighty = 1.0;
        c.anchor = GridBagConstraints.NORTHWEST;
        this.getContentPane().add(this.label_url_eingabe, c);


        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 1;
        c.gridy = 0;
        c.ipadx = 35;
        c.weightx = 1.0;
        c.weighty = 1.0;
        c.anchor = GridBagConstraints.NORTHWEST;
        add(this.url_eingabe, c);

    }   
}

这是主要的：

package ofb_reader_package;

import javax.swing.*;



public class OFB_Reader_main_class {

    public static void main(String[] args){

        new OFB_Reader_GUI();
        new OFB_Reader_main_class();

    }
}

Answer 1

非常感谢您的帮助！！我想我现在明白了：

package ofb_reader_package;

import javax.swing.*;

import java.awt.*;



public class OFB_Reader_GUI_and_Main  {





    public static void addComponentsToPane(Container pane) {

        JLabel label_url_eingabe;
        JTextField url_eingabe;

        pane.setLayout(new GridBagLayout());
        GridBagConstraints c = new GridBagConstraints();        

        label_url_eingabe = new JLabel("URL:");
        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 0;
        c.gridy = 0;
        pane.add(label_url_eingabe, c);

        url_eingabe = url_eingabe = new JTextField(10);
        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 1;
        c.gridy = 0;
        pane.add(url_eingabe, c);

    }

     private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("GridBagLayoutDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Set up the content pane.
        addComponentsToPane(frame.getContentPane());

        //Display the window.
        frame.pack();
        frame.setVisible(true);
        }   






public static void main(String[] args){

    //Schedule a job for the event-dispatching thread:
    //creating and showing this application's GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            createAndShowGUI();
        }
    });
}
}

Java GridBagLayout 组件未全屏显示

Java GridBagLayout components not shown in full screen

java

user-interface

gridbaglayout