java libgdx 在Java Libgdx中正确使用unProject

我想使按钮可单击，但是它不起作用-似乎需要使用，unproject()但我不知道如何使用。有问题的代码是：

Texture playButtonImage;

SpriteBatch batch;

ClickListener clickListener;

Rectangle playButtonRectangle;

Vector2 touchPos;

OrthographicCamera camera;

@Override

public void show() {

playButtonImage = new Texture(Gdx.files.internal("PlayButton.png"));

camera = new OrthographicCamera();

camera.setToOrtho(false, 800, 480);

batch = new SpriteBatch();

playButtonRectangle = new Rectangle();

playButtonRectangle.x = 400;

playButtonRectangle.y = 250;

playButtonRectangle.width = 128;

playButtonRectangle.height = 64;

}

@Override

public void render(float delta) {

Gdx.gl.glClearColor(0, 0, 0.2f, 1);

Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);

camera.update();

batch.setProjectionMatrix(bined);

batch.begin();

batch.draw(playButtonImage, playButtonRectangle.x, playButtonRectangle.y);

batch.end();

if (Gdx.input.isTouched()) {

Vector2 touchPos = new Vector2();

touchPos.set(Gdx.input.getX(), Gdx.input.getY());

if (playButtonRectangle.contains(touchPos)) {

batch.begin();

batch.draw(playButtonImage, 1, 1);

batch.end();

}

}

}