java - touchDragged 的​​奇怪行为

Question

我有一个简单的问题 - 我正在尝试对 Actor 进行拖动，但我看到了奇怪的效果 - 当我尝试拖动 Actor 时，它开始闪烁并随机改变位置。这是一个短视频:https://youtu.be/KpGujQ7KHc0

Actor 很简单:

public class Item extends Actor {
    private String id;
    private TextureRegion texture;

    public Item() {
        this.id = "passport";

        texture = PicturesData.getPicture(getId());
        setSize(texture.getRegionWidth(), texture.getRegionHeight());

        addListener(new DragListener() {
            @Override
            public boolean touchDown(InputEvent event, float x, float y, int pointer, int button) {
                return true;
            }

            @Override
            public void touchDragged(InputEvent event, float x, float y, int pointer) {
                Log.add("Dragged: " + x + ", " + y);
                setPosition(x, y);
            }
        });
    }

    public String getId() {
        return id;
    }

    @Override
    public void draw(Batch batch, float parentAlpha) {
        batch.draw(texture, getX(), getY());
    }
}

屏幕也很基本:

public class GameScreen implements Screen {
    private Stage stage;

    public GameScreen() {
        stage = new Stage(new StretchViewport(800, 600));
        Gdx.input.setInputProcessor(stage);

        Item item = new Item();

        stage.addActor(item);
    }

    @Override
    public void show() {
    }

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

        stage.act(delta);
        stage.draw();
    }

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

    }

    @Override
    public void pause() {

    }

    @Override
    public void resume() {

    }

    @Override
    public void hide() {

    }

    @Override
    public void dispose() {

    }
}

我不知道为什么会这样，你能帮我吗？

Answer 1

Pasha，您的 DragListener 没有任何问题。使用此项目(硬编码的起始位置):

public class Item extends Image {
    private String id;

    public Item(String id) {
        super(PicturesData.getPicture(getId());
        this.id = id;
        setPosition(50, 50);
        addListener(new DragListener() {
            @Override
            public boolean touchDown(InputEvent event, float x, float y, int pointer, int button) {
                return true;
            }

            @Override
            public void touchDragged(InputEvent event, float x, float y, int pointer) {
                moveBy(x - getWidth()/2, y - getHeight()/2);
            }
        });
    }

    public String getId() {
        return id;
    }
}