奇怪的行爲與touchDragged

Question

我有一個簡單的問題 - 我試圖阻止拖動演員，但我看到奇怪的效果 - 當我試圖拖動演員開始閃爍並隨機更改位置。這裏是一個簡短的視頻：https://youtu.be/KpGujQ7KHc0

演員很簡單：

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()); 
    } 
} 

屏幕是基本太：

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() { 

    } 
} 

我不知道爲什麼它的發生，你能幫幫我嗎？

Answer 1

Pasha，您的DragListener沒有任何問題。使用這個項目（起始位置硬編碼）：

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; 
    } 
} 

Answer 2

我認爲你的DragListener不能正常工作的原因是因爲你已經覆蓋了touchDown函數，這是偵聽器正常工作所必需的。只需將您的代碼更改爲：

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