为什么每次最小化窗口时我的 Java 程序都会刷新？

Question

I am making a palace game to understand and get better at programming in Java. Though I have run into an issue where every time I minimize the screen the variable that is selecting the card image constantly refreshes. For example the Randomizing function I have makes the variable pick a card depending on a digit and then it displays it, but it changes every time I minimize the page and open it again. I tried to look for the answer to my problem but I couldn't find it. My code for what I am doing is in the previous question I asked. My question is how do I stop my variables from refreshing every time minimize the page?

Edit: I just realized it also changes every time I move the window with my cursor if this helps.

This is my randomize function:

public void randomizer() {
        Random rand = new Random();
        int rand_int1 = rand.nextInt(15-1)+1;
        System.out.print(rand_int1);
        if (rand_int1 == 1) {
            setVariables(aceClover);

        }else if (rand_int1 == 2) {
            setVariables(twoClover);
        }else if (rand_int1 == 3) {
            setVariables(threeClover);
        }else if (rand_int1 == 4) {
            setVariables(fourClover);
        }else if (rand_int1 == 5) {
            setVariables(fiveClover);   
        }else if (rand_int1 == 6) {
            setVariables(sixClover);
        }else if (rand_int1 == 7) {
            setVariables(sevenClover);
        }else if (rand_int1 == 8) {
            setVariables(eightClover);
        }else if (rand_int1 == 9) {
            setVariables(nineClover);
        }else if (rand_int1 == 10) {
            setVariables(tenClover);
        }else if (rand_int1 == 11) {
            setVariables(jackClover);
        }else if (rand_int1 == 12) {
            setVariables(queenClover);
        }else if (rand_int1 == 13) {
            setVariables(kingClover);
        }else {
            System.out.println("Couldn't return any Cards!");
        }
    }

package MainClasses;
import java.awt.*;
import java.io.*;
import java.util.Random;

import javax.imageio.ImageIO;

public class DrawBoard extends Component{
    AllCards accessor = new AllCards();
    public void paint(Graphics g) { // function to draw onto the window
    Graphics2D g1 = (Graphics2D)g; // the component being used to access and write to the window
    g1.clearRect(0, 0, getWidth(), getHeight()); // clears rectangle every frame
    g1.setBackground(Color.green); // sets background color
    accessor.randomizer();
    g1.drawImage(accessor.imageExtract, 100, 100, null);
    }   
}

If you need the rest of the code its in this question:

The full code

It does have some minor changes because I fixed my previous problem all I did was make a new class and move the creation of those variables over to that class and removed them from my previous one.

Answer 1

Because you're calling the randomizer from within the paint method, and that method is called every time the gui gets minimized and restored, or any time it is resized.

solution: Don't do that, don't have any program logic within a painting method but instead have only painting code there.

Instead:

• Make the call from the class constructor which is only called once

Also:

• Don't extend Component but rather JPanel (don't mix AWT and Swing components)
• Paint within the JPanel's paintComponent method
• Call the super's painting method within the override super.paint(g) if you are overriding paint or super.paintComponent(g) if you override paintComponent. This allows "housekeeping" painting to occur, including the removal of "dirty" pixels.