Java Swing : JPanel only shows up once JFrame is scaled

Question

我正在开发一款迷你二十一点游戏，我刚进入 GUI，就遇到了一个小问题，我在一个 JFrame 中有 2 个 JPanel，但一旦我运行 main 方法，只会出现一个，并且上面会出现一个点我指定第二个面板位置的区域。一旦我用鼠标向上或向下或向任何方向缩放 JFrame，JPanel 就会出现在其正确的位置。我对如何解决这个问题感到有点困惑，因为我尝试了很多不同的方法但无法解决。任何帮助是极大的赞赏。代码如下:

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import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener; 

import javax.swing.BorderFactory;
import javax.swing.JFrame ; 
import javax.swing.JButton ;
import javax.swing.JLabel;
import javax.swing.JPanel ;
import javax.swing.JTextArea;
import java.awt.Dimension;
import javax.swing.Box;
import javax.swing.BoxLayout;


public class GUI extends JFrame implements ActionListener {


public GUI(){
    //Constructor for BlackJack 

    ///Frame/////////////////////////////////////////////
    super("BlackJack");  

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBackground(Color.WHITE);
    setLayout(new GridBagLayout());
    setSize(1051,550);
    setResizable(true);
    GridBagConstraints gbc = new GridBagConstraints();
    GridBagConstraints gbc2 = new GridBagConstraints();
    gbc.insets = new Insets(10,10,10,10);
    gbc2.insets= new Insets(10,10,10,10);


    // Creating all the necessary panels.
    JPanel scores = new JPanel(new GridBagLayout());
    JPanel dealer = new JPanel(); 
    JPanel player = new JPanel();
    JPanel bettingArea = new JPanel(new GridBagLayout());
    JPanel messages = new JPanel();  
    messages.setLayout(new BoxLayout(messages,BoxLayout.PAGE_AXIS));



    //Adding the panels to the Frame.

    gbc2.anchor=GridBagConstraints.NORTHEAST;
    add(scores,gbc2);

    gbc2.anchor=GridBagConstraints.LAST_LINE_START;
    add(bettingArea,gbc2);

    gbc2.anchor=GridBagConstraints.LAST_LINE_END;
    add(messages,gbc2);

    // Setting borders for each Panel.
    scores.setBorder(BorderFactory.createLineBorder(Color.DARK_GRAY, 3));
    bettingArea.setBorder(BorderFactory.createLineBorder(Color.DARK_GRAY, 3));
    messages.setBorder(BorderFactory.createLineBorder(Color.BLUE, 3));

    ////////End of Frame/////////////////////////////////////////////////

    //score's Interface //////////////////////////////
    /////////////////////////////////////////////////

    JButton hit = new JButton("Hit");
    JButton check = new JButton("Check");
    JLabel plrScore = new JLabel("Player Score");
    JLabel dlrScore = new JLabel("Dealer Score");

    // Setting Different Border Colors for the Player and Dealer
    plrScore.setBorder(BorderFactory.createLineBorder(Color.BLUE));
    dlrScore.setBorder(BorderFactory.createLineBorder(Color.BLACK));

    // Setting up the GridBagConstraints.
    gbc.gridx=0;
    gbc.gridy=0;
    scores.add(plrScore,gbc);

    gbc.gridx=1;
    gbc.gridy=0;
    scores.add(dlrScore,gbc);

    gbc.gridx=0;
    gbc.gridy=1;
    scores.add(hit,gbc);

    gbc.gridx=1;
    gbc.gridy=1;
    scores.add(check,gbc); 


    //bettingArea's Interface //////////////////////////
    ///////////////////////////////////////////////////
    JButton increaseBet = new JButton("Increase");
    JButton decreaseBet = new JButton("Decrease");
    JTextArea playerBet = new JTextArea("Player Bet");
    JTextArea playerCash = new JTextArea("Player Cash"); 

    // Setting Different Borders for the Objects
    playerBet.setBorder(BorderFactory.createRaisedSoftBevelBorder());
    playerCash.setBorder(BorderFactory.createRaisedSoftBevelBorder());


    // Setting up the GridBagConstraints.
    gbc.gridx=0;
    gbc.gridy=0;
    bettingArea.add(increaseBet,gbc);

    gbc.gridx=1;
    gbc.gridy=0;
    bettingArea.add(playerBet,gbc);

    gbc.gridx=0;
    gbc.gridy=1;
    bettingArea.add(decreaseBet,gbc);

    gbc.gridx=1;
    gbc.gridy=1;
    bettingArea.add(playerCash,gbc);

    ////messages Interface///////////////////// 

    JTextArea msg1 = new JTextArea("Message 1"); 
    JTextArea msg2 = new JTextArea("Message 2"); 
    JTextArea msg3 = new JTextArea("Message 3"); 
    JTextArea msg4 = new JTextArea("Message 4"); 

    messages.add(msg1); 
    messages.add(Box.createRigidArea( new Dimension(0,2)));
    messages.add(msg2);
    messages.add(Box.createRigidArea( new Dimension(0,2)));
    messages.add(msg3);
    messages.add(Box.createRigidArea( new Dimension(0,2)));
    messages.add(msg4);


    //Visibility of Panels & JFrame.
    scores.setVisible(true);
    bettingArea.setVisible(true);
    messages.setVisible(true);
    setVisible(true); 




}





public void actionPerformed(ActionEvent arg0) {
    // TODO Auto-generated method stub

}


// Main Method
public static void main ( String args[]){
    GUI game = new GUI();
}

}

Answer 1

您需要从 GUI() 构造函数中删除 setVisible(true);。而是将其放在 main() 函数和 SwingUtilities.invokeLater() 中，如下所示:

public static void main ( String args[]){
    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            new GUI().setVisible(true);
        }
    });
}

Swing gui更新和渲染任务应该在EDT(事件调度线程)中执行。上面的调用就是为我们做的。