重绘图形时添加到 Jframe 的 Textfield 消失

Question

我在使用 JFrame 文本字段时遇到问题。
我正在尝试制作一个文字游戏，但问题是当我尝试创建文本字段以设置输入然后检查它是否是正确的词时，我已经涵盖了这个词。
问题是当我尝试添加 Textfield 时，当我将内容渲染到 JFrame 时它消失了。

public teksti() {

    setTitle("Hirsipuu");
    setSize(leveys,korkeus);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setResizable(false);
    setVisible(true);
    setLocationRelativeTo(null);
    setBackground(Color.white);
    jp.add(tf); // adding JtextField (JTextField tf = new JTextField(30);)
    add(jp);        
}

我的render()是这样的（只是为了测试）。

private void render() {
    BufferStrategy bs = this.getBufferStrategy(); // tehdään uusi bufferi

    if (bs == null) {
        createBufferStrategy(3);
        return;
    }

    int R = (int) (Math.random( )*256);
    int G = (int)(Math.random( )*256);
    int B= (int)(Math.random( )*256);
    Color randomColor = new Color(R, G, B);
    Graphics g = bs.getDrawGraphics();

    g.drawString("Arvaa sana", 100 , 100);

    g.setColor(Color.white);
    g.fillRect(0, 50, leveys, korkeus);
    g.setColor(randomColor);
    g.setFont(h);
//  g.drawLine(0,0,liikey*2-1,liikex);
    for(int i = 0; i < salat.size(); i ++) {
        g.drawString(salat.get(i),liikex+rand.nextInt(50),liikey+rand.nextInt(50));
    }
    System.out.println(liikex + " " + liikey);

    g.dispose();
    bs.show();
    g.dispose();
}

开始时我可以让文本框显示在顶部，但随后它就消失了。
任何人都知道是否有更好的方法来做到这一点？

Answer 1

不要直接在 JFrame 中绘制
相反，如果您需要绘制背景图像，请在 JPanel 的 paintComponent 方法中进行。这可能比使用 BufferStrategy 更适合您的目的。
然后您可以向此 JPanel 添加组件，例如您的 JTextField。
然后将此 JPanel 添加到您的 JFrame。
始终在您自己的 paintComponent 方法覆盖中调用 super 的 paintComponent 方法。
注意永远不要处理从 JVM 提供给您的 Graphics 对象，例如传递给您的 paintComponent 方法的对象。

例如：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import javax.swing.*;

public class BackgroundPanel extends JPanel {
   private static final int PREF_W = 800;
   private static final int PREF_H = 600;
   private static final Font PROMPT_FONT = new Font(Font.SANS_SERIF, Font.BOLD,
         24);
   private Paint gradientPaint;
   private JTextField textField = new JTextField(20);

   public BackgroundPanel() {
      int red = (int) (Math.random() * 256);
      int green = (int) (Math.random() * 256);
      int blue = (int) (Math.random() * 256);
      Color color1 = new Color(red, green, blue);
      red = (int) (Math.random() * 256);
      green = (int) (Math.random() * 256);
      blue = (int) (Math.random() * 256);
      Color color2 = new Color(red, green, blue);

      gradientPaint = new GradientPaint(0, 0, color1, 20, 20, color2, true);

      JLabel promptLabel = new JLabel("Input:");
      promptLabel.setFont(PROMPT_FONT);
      add(promptLabel);
      add(textField);
   }

   @Override
   protected void paintComponent(Graphics g) {
      super.paintComponent(g);
      Graphics2D g2 = (Graphics2D) g;
      g2.setPaint(gradientPaint);
      g.fillRect(0, 0, getWidth(), getHeight());
      g.setColor(Color.black);
      g.setFont(PROMPT_FONT);
      g.drawString("Arvaa sana", 100, 100);
   }

   @Override
   public Dimension getPreferredSize() {
      if (isPreferredSizeSet()) {
         return super.getPreferredSize();
      }
      return new Dimension(PREF_W, PREF_H);
   }

   private static void createAndShowGui() {
      BackgroundPanel mainPanel = new BackgroundPanel();

      JFrame frame = new JFrame("BackgroundPanel");
      frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

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

Answer 2

这基本上是我现在完成的全部工作。

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;


public class teksti extends JFrame implements Runnable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
ArrayList<String> sanat = new ArrayList<String>();
ArrayList<String> salat = new ArrayList<String>();
String dir =  System.getProperty("user.dir");
String pathname = dir  + "\src\kotus_sanat.txt";
Random rand = new Random();
Scanner lukija = new Scanner(System.in);
String syote,salasana,salasana2;
int leveys=500,korkeus=500;
int liikex=300, liikey=300;
Font h = new Font("Helvetica", Font.PLAIN, 18);
JTextField tf = new JTextField(30);
JPanel jp = new JPanel();
JFrame jf = new JFrame();


  public teksti() {

    setTitle("Hirsipuu");
    setSize(leveys,korkeus);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setResizable(false);
    setVisible(true);
    setLocationRelativeTo(null);
    setBackground(Color.white);
    jp.add(tf);
    add(jp);

}

public static void main(String args[]){
     teksti teksti = new teksti();
     teksti.start();

}


private void start() {
    run();

}


public void run() {


    sanat = lataa();
    System.out.println(pathname);

    System.out.println(sanat.size() + " sanaa ladattu..");
    int sanoja=sanat.size();



    for (int i = 0; i < 10; i++){
    salat.add(sanat.get(rand.nextInt(sanoja)));
    }
    System.out.println("salasana on " + salasana);
    long lastTime = System.nanoTime(); // fps sälää
    long timer = System.currentTimeMillis();
    final double ns = 1000000000.0 / 60.0;
    double delta = 0;
    int frames = 0;
    int updates = 0;
    requestFocus();

    boolean running=true;
    while (running){
         long now = System.nanoTime();
         delta += (now-lastTime) / ns;
         lastTime = now;
         while ( delta >= 1) {
            update();
            updates++;
            delta--;    
        }
        render();
         frames++;

         if (System.currentTimeMillis() - timer > 1000){
            timer += 1000;
            setTitle("Hirsipuu"+ "    |    " + updates + " ups " +   frames + " fps" );
            updates = 0;
            frames = 0;
        }   
    }
 }

 private void update() {
    liikex = liikex + 1;
    liikey= liikey - 4;
    if (liikey>korkeus)
        liikey = 1;
    if (liikex>leveys)
        liikex= 1;
    if (liikey<20)
        liikey = korkeus;


 }
 private void render() {
    BufferStrategy bs = this.getBufferStrategy(); // tehdään uusi bufferi

    if (bs == null) {
        createBufferStrategy(3);
        return;
    }


    int R = (int) (Math.random( )*256);
    int G = (int)(Math.random( )*256);
    int B= (int)(Math.random( )*256);
    Color randomColor = new Color(R, G, B);
    Graphics g = bs.getDrawGraphics();



g.drawString("Arvaa sana", 100 , 100);

g.setColor(Color.white);
g.fillRect(0, 50, leveys, korkeus);
    g.setColor(randomColor);
    g.setFont(h);
//  g.drawLine(0,0,liikey*2-1,liikex);
    for(int i = 0; i < salat.size(); i ++) {
    g.drawString(salat.get(i),  liikex+rand.nextInt(50),liikey+rand.nextInt(50));
        }
    System.out.println(liikex + " " + liikey);

 g.dispose();
 bs.show();


  g.dispose();
 }






private void stop() {


}



private void vertaa() {
    System.out.println("Anna sana niin tarkastaan onko se oikea suomenkielinen sana: ");
    syote = lukija.next();

    boolean oikea = false;
    int i = 0;
    int z = 0;
    while (i < sanat.size()) { 
        if (syote.equals(sanat.get(i))) {
            oikea = true;
            System.out.println (syote + " on oikea suomalainen sana.");
            break;

        }
        else{



         }

        }
    if (!oikea) {
        System.out.println(syote + " ei ole oikea suomalainen sana.");
    }


 }



 public ArrayList<String> lataa() {



    String line = null;

    try {

        BufferedReader reader = new BufferedReader(new FileReader(pathname));
        while((line = reader.readLine()) != null){
            sanat.add(line);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return sanat;
    }


}

             vertaa() is not used.

重绘图形时添加到 Jframe 的 Textfield 消失

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