JAVA AWT Frame窗口未调整大小时不显示组件问题无法修复

问题原因 #

你的代码存在setVisible调用时机错误的问题：你在仅添加了panel_1的时候就调用了frame.setVisible(true)将窗口设为可见，后续添加的输入框、按钮面板及所有按钮都没有触发窗口的重绘逻辑，因此会出现偶发不显示的问题。手动调整窗口大小时会自动触发界面重绘，所以隐藏的组件会立即显示。

修复方法 #

将frame.setVisible(true)语句移动到所有组件添加、配置完成的最后一行即可，同时可以额外增加重绘验证语句避免渲染异常。

修改后的完整代码如下：

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class CalculatorUsingAWT {
    CalculatorUsingAWT(){
        Frame frame = new Frame("CALCKY");
        Panel panel_1 = new Panel();
        panel_1.setBounds(0,0,400,100);
        panel_1.setBackground(new Color(43, 11, 51));
        frame.add(panel_1);
        frame.setLayout(null);
        frame.setBounds(550,100,400,549);
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        TextField textField = new TextField();
        textField.setBounds(25,45,350,40);
        textField.setBackground(new Color(43, 11, 51));
        textField.setForeground(Color.WHITE);
        textField.setFont(new Font("SAN_SERIF",Font.BOLD,30));
        textField.setEditable(false);
        panel_1.setLayout(null);
        panel_1.add(textField);

        Panel panel_2 = new Panel();
        panel_2.setLayout(new GridLayout(6,4));
        panel_2.setBounds(0,100,401,450);
        panel_2.setBackground(new Color(43, 11, 51));
        frame.add(panel_2);
        Button button_1 = new Button("1");
        button_1.setBackground(new Color(43, 11, 51));
        button_1.setFont(new Font("ARIAL",Font.BOLD,30));
        button_1.setForeground(Color.WHITE);
        Button button_2 = new Button("2");
        button_2.setBackground(new Color(43, 11, 51));
        button_2.setFont(new Font("ARIAL",Font.BOLD,30));
        button_2.setForeground(Color.WHITE);
        Button button_3 = new Button("3");
        button_3.setBackground(new Color(43, 11, 51));
        button_3.setFont(new Font("ARIAL",Font.BOLD,30));
        button_3.setForeground(Color.WHITE);
        Button button_4 = new Button("4");
        button_4.setBackground(new Color(43, 11, 51));
        button_4.setFont(new Font("ARIAL",Font.BOLD,30));
        button_4.setForeground(Color.WHITE);
        Button button_5 = new Button("5");
        button_5.setBackground(new Color(43, 11, 51));
        button_5.setFont(new Font("ARIAL",Font.BOLD,30));
        button_5.setForeground(Color.WHITE);
        Button button_6 = new Button("6");
        button_6.setBackground(new Color(43, 11, 51));
        button_6.setFont(new Font("ARIAL",Font.BOLD,30));
        button_6.setForeground(Color.WHITE);
        Button button_7 = new Button("7");
        button_7.setBackground(new Color(43, 11, 51));
        button_7.setFont(new Font("ARIAL",Font.BOLD,30));
        button_7.setForeground(Color.WHITE);
        Button button_8 = new Button("8");
        button_8.setBackground(new Color(43, 11, 51));
        button_8.setFont(new Font("ARIAL",Font.BOLD,30));
        button_8.setForeground(Color.WHITE);
        Button button_9 = new Button("9");
        button_9.setBackground(new Color(43, 11, 51));
        button_9.setFont(new Font("ARIAL",Font.BOLD,30));
        button_9.setForeground(Color.WHITE);
        Button button_10 = new Button("+");
        button_10.setBackground(new Color(43, 11, 51));
        button_10.setFont(new Font("ARIAL",Font.BOLD,30));
        button_10.setForeground(Color.WHITE);
        Button button_11 = new Button("-");
        button_11.setBackground(new Color(43, 11, 51));
        button_11.setFont(new Font("ARIAL",Font.BOLD,30));
        button_11.setForeground(Color.WHITE);
        Button button_12 = new Button("*");
        button_12.setBackground(new Color(43, 11, 51));
        button_12.setFont(new Font("ARIAL",Font.BOLD,30));
        button_12.setForeground(Color.WHITE);
        Button button_13 = new Button("/");
        button_13.setBackground(new Color(43, 11, 51));
        button_13.setFont(new Font("ARIAL",Font.BOLD,30));
        button_13.setForeground(Color.WHITE);
        Button button_14 = new Button("=");
        button_14.setBackground(Color.BLUE);
        button_14.setFont(new Font("ARIAL",Font.BOLD,30));
        button_14.setForeground(Color.WHITE);
        Button button_15 = new Button("%");
        button_15.setBackground(new Color(43, 11, 51));
        button_15.setFont(new Font("ARIAL",Font.BOLD,30));
        button_15.setForeground(Color.WHITE);
        Button button_16 = new Button("CE");
        button_16.setBackground(new Color(43, 11, 51));
        button_16.setFont(new Font("ARIAL",Font.BOLD,30));
        button_16.setForeground(Color.WHITE);
        Button button_17 = new Button("C");
        button_17.setBackground(new Color(43, 11, 51));
        button_17.setFont(new Font("ARIAL",Font.BOLD,30));
        button_17.setForeground(Color.WHITE);
        Button button_18 = new Button("x^2");
        button_18.setBackground(new Color(43, 11, 51));
        button_18.setFont(new Font("ARIAL",Font.BOLD,30));
        button_18.setForeground(Color.WHITE);

        panel_2.add(button_1);
        panel_2.add(button_2);
        panel_2.add(button_3);
        panel_2.add(button_4);
        panel_2.add(button_5);
        panel_2.add(button_6);
        panel_2.add(button_7);
        panel_2.add(button_8);
        panel_2.add(button_9);
        panel_2.add(button_10);
        panel_2.add(button_11);
        panel_2.add(button_12);
        panel_2.add(button_13);
        panel_2.add(button_14);
        panel_2.add(button_15);
        panel_2.add(button_16);
        panel_2.add(button_17);
        panel_2.add(button_18);

        // 将setVisible移到所有组件配置完成之后
        frame.setVisible(true);
        // 可选添加验证和重绘逻辑，确保所有组件渲染生效
        frame.validate();
        frame.repaint();
    }

    public static void main(String[] args) {
        new CalculatorUsingAWT();
    }
}

内容的提问来源于stack exchange，提问作者Rudransh Singh Mahra