JFrame中JLabel不显示文字

代码如下

import controller.UserController;
import model.ChessPiece;

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

public class UserFrame extends JFrame {
    public static UserController userController;
    MediaTracker tracker;
    Image UserImage;
    private JButton logInBtn;
    private JButton registerBtn;
    private JLabel introduceLabel;
    public UserFrame(int frameSize){
        this.setTitle("User's Panel");
        this.setLayout(null);
        setResizable(false);


        this.setSize(frameSize , frameSize);//设置窗口边界

        this.setLocationRelativeTo(null);

        this.tracker = new MediaTracker(this);
        UserImage = Toolkit.getDefaultToolkit().getImage("E:\\Java Learning\\project image\\进入.png\\");
        tracker.addImage(UserImage,1);
        try{
            tracker.waitForAll();;
        }catch (InterruptedException e){
            System.out.println("加载图象文件失败");
        }

        this.introduceLabel = new JLabel();
        introduceLabel.setText("Let us play CHESS!");
        introduceLabel.setFont(new Font("Calibri", Font.ITALIC, 50));
        introduceLabel.setSize((int)(this.getWidth()*0.6),(int)(this.getHeight()*0.2));
        introduceLabel.setLocation((int)(this.getWidth()*0.2),(int)(this.getHeight()*0.5));
        introduceLabel.setVisible(true);
        this.add(introduceLabel);

        this.registerBtn = new JButton("注册");
        registerBtn.setSize((int)(this.getWidth()*0.25), (int)(this.getHeight()*0.1));
        registerBtn.setLocation((int) (this.getWidth()*0.2), (int)(this.getHeight()*0.7));
        add(registerBtn);
        registerBtn.addActionListener(e -> {
            System.out.println("click register Btn");
        });


        this.logInBtn = new JButton("登录");
        logInBtn.setSize((int)(this.getWidth()*0.25), (int)(this.getHeight()*0.1));
        logInBtn.setLocation((int) (this.getWidth()*0.55), (int)(this.getHeight()*0.7));
        add(logInBtn);
        logInBtn.addActionListener(e -> {
            System.out.println("click log in Btn");
        });



        this.setVisible(true);
        this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }
    public void paint(Graphics g){
        g.drawImage(UserImage,(int) (this.getWidth()*0.37),(int)(this.getHeight()*0.2),(int)(this.getWidth()*0.25),(int)(this.getHeight()*0.25),this);
        logInBtn.requestFocus();
        registerBtn.requestFocus();
        introduceLabel.requestFocus();
    }
}

估计被你图片给覆盖了。你把图片去掉试试。