如何保存高分值并在应用程序关闭时加载它

Question

我使用首选项来保存值。它运行良好并保存了高分，但是当我重新打开游戏时，高分变为默认零

有没有办法让我重新打开应用程序时分数保持不变？

我只有一个扩展应用程序适配器的类，而我的偏好代码在渲染方法中是问题的原因吗？

这是我的代码 -

Override
public void render() 
{
    if (secondsLeft <= 0)
    {
        gameOver = true;
    }

    Gdx.gl.glClearColor(r, g, b, 0.5f);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    batch.begin();

    if (!gameOver) 
    {   
        sadMusic.stop();
        bgMusic.setVolume(0.4f);
        bgMusic.setLooping(true);
        bgMusic.play();
        
        batch.draw(targetTexture, targetRect.x, targetRect.y, targetRect.width, targetRect.height);

        font.draw(batch, "Time Left: " + secondsLeft, 250, Gdx.graphics.getHeight() - 60);
        font.draw(batch, "Your Score: " + score, 210, 150);

        if (Gdx.input.justTouched())
        {
            System.out.println(delay);
            Vector2 touchPosition = new Vector2(Gdx.input.getX(), Gdx.graphics.getHeight() - Gdx.input.getY());

            Rectangle touchedRect = new Rectangle(touchPosition.x, touchPosition.y, 1, 1);
            if (Intersector.overlaps(touchedRect, targetRect))
            {
                score++;

                long id = tapSound.play(1.0f);
                tapSound.setPitch(id, 0.1f);
                tapSound.setLooping(id, false);

                changeTargetPosition();
                Gdx.gl.glClearColor(r, g, b, 0.5f);
            }
        }
        
        pref= Gdx.app.getPreferences("highScore");
        
        if (score >= highScore) {
            pref.putInteger("High Score", score);
            pref.flush();
        }
        highScore = pref.getInteger("High Score", 0);
    } 
    else
    {
        bgMusic.stop();
        sadMusic.setVolume(0.4f);
        sadMusic.setLooping(true);
        sadMusic.play();
        
        Gdx.gl.glClearColor(1, 0, 0, 0.5f);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        font.draw(batch, "Game over!", 240, Gdx.graphics.getHeight() - 60);
        font.draw(batch, "Score was: " + score, 220, Gdx.graphics.getHeight() - 170);
        font.draw(batch, "Tap To Restart", 220, Gdx.graphics.getHeight() - 709);
        font.draw(batch, "High Score: " + highScore, 200, Gdx.graphics.getHeight() - 750);
        
        /* using this so that usr wont click the screen bymistakenly 
         bcz when we were playing the game it kind of catches 
         the rythem, and hence needs some time to stop */
        
        delay += Gdx.graphics.getDeltaTime();

        if (delay >= 1f) {
            if (Gdx.input.justTouched())
            {
                startGame();
            }
        }
        
    }
    batch.end();
}

Answer 1

您的highscore 值将在每次游戏开始时被覆盖，因为您没有先读取该值（至少在渲染方法中）：

//...
pref= Gdx.app.getPreferences("highScore");

//here highScore was not initialized yet (so it's probably 0, just like score)
if (score >= highScore) {//this will always be true in the first call of the render method
    pref.putInteger("High Score", score);//now the High Score value is overwritten and is 0 again (no matter what it was before)
    pref.flush();
}
highScore = pref.getInteger("High Score", 0);//here you read the overwritten value, but not the stored one
//...

您可以通过在比较之前加载值来解决此问题：

//...
pref= Gdx.app.getPreferences("highScore");
highScore = pref.getInteger("High Score", 0);//load the value, so you can compare score against the real high score

if (score >= highScore) {//now highScore is initialized and this will be false (if the stored highScore was greater than 0)
    pref.putInteger("High Score", score);
    pref.flush();
}
//...