Libgdx preferences doesn't save properly

Question

So I'm having this problem with libgdx and using preferences. Preferences is supposed to save the float "value" and it does too, but when I kill my app from Android task manager or restart my Android system, the float is back on its default value. I have read that this may be caused by the static value of the float, but I'm not able to remove the static from the float because I'm using the float with my GestureDetector class. Can I make a new float to GestureDetector class and reference float "value" to decrease when the new float is decreased or something?

Here is my main code:

public class WorldScreen implements Screen{

Preferences prefs;

private Texture bgCity;
private Texture bgLoop;
private Texture bgEnd;
private Texture bgFade;
private Texture hud;

public static OrthographicCamera camera;
SpriteBatch batch;

Rectangle player;
Rectangle background;
Rectangle backgroundloop;

public float time = 100;
public float camx = 0;
public float camy = 0;
public static float score = 384400000f;
public static float value = 384400000f;
BitmapFont font;
GestureListenerC controller;

private Music startmusic;
private static Music loopmusic;
private Music endMusic;

public static boolean ending = false;

private int endint;
private String endstring = "";

public WorldScreen(final JetpackGame aa) {

}

@Override
public void render(float delta) {
    Gdx.gl.glClearColor(0, 0, 0, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    value += GestureListenerC.implementvalue;
    camx = camera.viewportWidth / 2f;
    camy = camera.viewportHeight / 2f;

    controller.update();
    camera.update();

    batch.setProjectionMatrix(camera.combined);
    batch.begin();

    batch.draw(bgCity, background.x, background.y);
    batch.draw(bgLoop, backgroundloop.x, backgroundloop.y);
    batch.draw(bgEnd, 0, 5360);

     if(!ending){
    if(camera.position.y >= 5360) camera.position.y = 4096;
     }

    if(value <= 0) ending = true;
    //ENDING
    if(ending){
        time += 0.1f * Gdx.graphics.getDeltaTime();
        startmusic.stop();
        loopmusic.stop();
        if(time <= 102.75f){
            camera.position.y += 0.15f * time;
            if(camera.position.y >= 5360) camera.position.y = 4096;
        }
        if(time >= 102.75f) {
            if (camera.position.y >= 4090 && camera.position.y <= 6666)
                camera.position.y += 0.15f * time;
        }
        endMusic.play();
        font.setScale(2.0f);
        font.draw(batch, "You already finished the game xD", 0,1200);
        if(time >= 103.2f)endMusic.stop();

    }


    Matrix4 normalProjection = new Matrix4().setToOrtho2D(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
    batch.setProjectionMatrix(normalProjection);

    batch.draw(hud, 0, 85, Gdx.graphics.getWidth(), 1200);

    font.setScale(3.5f);
    if(time <=102.5f) {
        font.draw(batch, ">Meters to the moon", 10, 1260);
        font.draw(batch, ">" + (int)value + "m", 10, 1190);
    }
    //font.draw(batch,""+time, 100, 100);
    //font.draw(batch,""+value, 100,120);
    if(time >= 103) {
        font.setScale(3.0f);
        font.draw(batch, ">"+endstring, 10,1200);
    }

    if(time >= 104)
    batch.draw(bgFade, 0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());

    batch.end();

    if(value < 0) value = 0;

    if(!startmusic.isPlaying()) {
        loopmusic.setLooping(true);
        loopmusic.play();
    }

    //RANDOM ENDING GENERATOR
    switch(endint){
        case 1: endstring = "Now do it again faster!";
            break;
        case 2: endstring = "What are you doing with your life?!";
            break;
        case 3: endstring = "Do you want a cookie?";
            break;
        case 4: endstring = "How many hours did you waste?";
            break;
        case 5: endstring = "So you have no life?";
            break;
        case 6: endstring = "Now get out of your room and go outside!";
            break;
      }

}
@Override
public void resize(int width, int height) {

}

@Override
public void show() {

    Random rand = new Random();
    endint = rand.nextInt(6);

    font = new BitmapFont();
    font.setColor(Color.GREEN);

    Preferences prefs = Gdx.app.getPreferences("My Preferences");
    float value = prefs.getFloat("Value", 384400000f);

    controller = new GestureListenerC();
    GestureDetector gestureDetector = new GestureDetector(20, 0.5f, 2, 0.15f, controller);
    Gdx.input.setInputProcessor(gestureDetector);

    loopmusic = Gdx.audio.newMusic(Gdx.files.internal("audio/AmbientLoop.ogg"));
    startmusic = Gdx.audio.newMusic(Gdx.files.internal("audio/AmbientStart.ogg"));
    endMusic = Gdx.audio.newMusic(Gdx.files.internal("audio/Moon.ogg"));
    endMusic.setLooping(false);
    startmusic.play();

    bgCity = new Texture(Gdx.files.internal("img/city_BG.png"));
    bgLoop = new Texture(Gdx.files.internal("img/loopBG.png"));
    bgEnd = new Texture(Gdx.files.internal("img/endBG.png"));
    bgFade = new Texture(Gdx.files.internal("img/fade.png"));
    hud = new Texture(Gdx.files.internal("img/Hud.png"));

    camera = new OrthographicCamera();
    camera.setToOrtho(false, 480,854);
    batch = new SpriteBatch();

    background = new Rectangle();
    background.x = 0;
    background.y = 0;
    background.width = 479;
    background.height = 4096;

    backgroundloop = new Rectangle();
    backgroundloop.x = 0;
    backgroundloop.y = 4096;
    backgroundloop.width = 512;
    backgroundloop.height = 1024;
}

@Override
public void hide() {

}

@Override
public void pause() {

}

@Override
public void resume() {

}

@Override
public void dispose() {
    prefs.putFloat("Value", value);
    prefs.flush();
    batch.dispose();
    font.dispose();
    bgCity.dispose();
    bgLoop.dispose();
    bgEnd.dispose();
    bgFade.dispose();
    hud.dispose();
    loopmusic.dispose();
    startmusic.dispose();
    endMusic.dispose();
}

}

And here is my GestureDetector class:

public class GestureListenerC implements GestureListener{

public static float velX, velY;
public static boolean flinging = false;
float initialScale = 1;
public static float implementvalue = 0;

public boolean touchDown (float x, float y, int pointer, int button) {
    flinging = false;
    initialScale = WorldScreen.camera.zoom;
    return false;
}

@Override
public boolean tap (float x, float y, int count, int button) {
    //Gdx.app.log("GestureDetectorTest", "tap at " + x + ", " + y + ", count: " + count);
    return false;
}

@Override
public boolean longPress (float x, float y) {
    //Gdx.app.log("GestureDetectorTest", "long press at " + x + ", " + y);
    return false;
}

@Override
public boolean fling (float velocityX, float velocityY, int button) {
    //Gdx.app.log("GestureDetectorTest", "fling " + velocityX + ", " + velocityY);
    flinging = true;
    velY = WorldScreen.camera.zoom * velocityY * 0.5f;
    //if(WorldScreen.value <= 0)WorldScreen.value = 0;
    return false;
}

@Override
public boolean pan (float x, float y, float deltaX, float deltaY) {
    // Gdx.app.log("GestureDetectorTest", "pan at " + x + ", " + y);
    if(deltaY >= 0) {
        if (!WorldScreen.ending) {
            //if (WorldScreen.value != 0) {
                WorldScreen.camera.position.add(0, Math.abs(deltaY * WorldScreen.camera.zoom), 0);
                WorldScreen.value -= Math.abs(1 * deltaY);
            //}
            if (WorldScreen.camera.position.y <= 0) WorldScreen.camera.position.y = 0;
        }
    }
    //if(WorldScreen.value <= 0)WorldScreen.value = 0;
    return false;
}

@Override
public boolean panStop (float x, float y, int pointer, int button) {
    //Gdx.app.log("GestureDetectorTest", "pan stop at " + x + ", " + y);
    return false;
}

@Override
public boolean zoom (float originalDistance, float currentDistance) {

    return false;
}

@Override
public boolean pinch (Vector2 initialFirstPointer, Vector2 initialSecondPointer, Vector2 firstPointer, Vector2 secondPointer) {
    return false;
}

public void update () {
    if(!WorldScreen.ending){
        if (flinging) {

            //if(WorldScreen.value != 0){
                velY *= 0.98f;
                if(velY >= 0) {
                    WorldScreen.value -= 100.5f * velY;
                    WorldScreen.camera.position.add(0, velY * Gdx.graphics.getDeltaTime(), 0);
                }

                if (velY < 0.01f) velY = 0;
        //}
        //if(WorldScreen.camera.position.y <= 480){ WorldScreen.camera.position.y = 480; WorldScreen.value = 384400000;}
    }
        }
    //if(WorldScreen.value <= 0)WorldScreen.value = 0;
}
}

Answer 1

如果您正在为Android设计，那么您可以切换到android的'SharedPreferences'