java - JTextfield 不像我想要的那样显示

Question

我是 Java 新手，找不到简单的解决方案。在下图中，您可以看到我的问题是什么。我想写一个程序，我可以在其中创建播放列表并保护它们，但我已经卡在了开头，因为 JTextfield 太小了。

import javax.swing.JFrame;

public class Main {
    
    public static void main(String args[]) {
        JFrame w = new Layout();
        w.setVisible(true);
        w.setSize(600, 600);
        w.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        w.setLocationRelativeTo(null);
        w.setResizable(true);
    }
}

import java.awt.*;
import javax.swing.*;
import javax.swing.border.LineBorder;

public class Layout extends JFrame{

        JTextField input;
    
    Layout(){   
        
        //title and layout type
        super("ThePlay");
        setLayout(new FlowLayout());
        
        JButton s;  //search button
        JButton h;  //home button
        JButton mp; //my playlist button
        JButton cp; //create playlist button
        JButton fs; //favorite songs button

        //frame constructor
        Container mainContainer = this.getContentPane();
        mainContainer.setLayout(new BorderLayout(8,6));
        mainContainer.setBackground(Color.GRAY);
        this.getRootPane().setBorder(BorderFactory.createMatteBorder(4, 4, 4, 4, Color.GRAY));
        
        //input constructor
        input = new JTextField();
        input.setBounds(300, 50, 150, 25);
        
        //up frame
        JPanel topPanel = new JPanel();
        topPanel.setBorder(new LineBorder(Color.BLACK, 3));
        topPanel.setBackground(Color.GRAY);
        topPanel.setLayout(new FlowLayout(6));
        
        //bot frame
        JPanel downPanel = new JPanel();
        downPanel.setBorder(new LineBorder(Color.BLACK, 3));
        downPanel.setBackground(Color.GRAY);
        downPanel.setLayout(new FlowLayout(5));
        
        //create buttons
        s = new JButton("Search");
        h = new JButton("Home");
        mp = new JButton("My Playlists");
        cp = new JButton("Create Playlist");
        fs = new JButton("Favorite Songs");
        
        
        //add buttons to the frame
        mainContainer.add(topPanel,BorderLayout.NORTH);     //top frame location
        mainContainer.add(downPanel,BorderLayout.CENTER);   //bottom frame location
        topPanel.add(input);
        topPanel.add(s);
        topPanel.add(h);
        topPanel.add(mp);
        topPanel.add(cp);
        topPanel.add(fs);   
    }
}

Answer 1

你可以通过这种方式给 JTextField 一个大小:

input = new JTextField(20);

来自documentation :

The integer argument passed to the JTextField constructor, 20 in theexample, indicates the number of columns in the field. This number isused along with metrics provided by the field's current font tocalculate the field's preferred width. It does not limit the number ofcharacters the user can enter.