四、实例代码

1.所用素材 ：图片（白色球，可能因为背景原因会看不到）  图片（银色星星）

3.创建舞台，实例化需要用的纹理图片，同时实现输入接口，来处理触屏事件。

stage = new Stage();
starTexture = new Texture(Gdx.files.internal("study/action/star.png"));
ballTexture = new Texture(Gdx.files.internal("study/action/ball.png"));
Gdx.input.setInputProcessor(this);

4.重写touchDragged方法，触摸屏幕时实例化出小球或星星

@Override
	public boolean touchDragged(int screenX, int screenY, int pointer) {
		createStar(MathUtils.randomBoolean(),
				screenX, 480 - screenY,MathUtils.random(10, 20));
		return false;
	}

5.实例化出小球或星星

//利用随机boolean来随机创建ball或star
	private void createStar(boolean randomBoolean, int x, int y, int size) {
		if (randomBoolean == true) {
			image = new Image(starTexture);
		} else if (randomBoolean == false) {
			image = new Image(ballTexture);

		}
		this.setAction(image);
		image.setPosition(x - size / 2, y - size / 2);
		image.setSize(size, size);
		stage.addActor(image);
	}

6.编写setAction(image)方法，把传进行的image对象（image也是actor）进行动作设置

public void setAction(final Image image) {
		float duration = MathUtils.random(1, 5);
		float scale = MathUtils.random(0.5f, 2.0f);
		float rotate = MathUtils.random(360);

		Action endAction = Actions.run(new Runnable() {
			@Override
			public void run() {
				System.out.println("All action is completed");
			}
		});

		MoveToAction moveto = Actions.moveTo(320, 240, duration);
		ScaleToAction scaleto = Actions.scaleTo(scale, scale, duration);
		RotateToAction rotateto = Actions.rotateTo(rotate, duration);
		SequenceAction alpha = Actions.sequence(Actions.fadeIn(duration),Actions.fadeOut(duration), endAction);
		ParallelAction Paction = Actions.parallel(moveto, scaleto, rotateto,alpha);
		RepeatAction repeatedAction = Actions.repeat(3, Paction);
		RepeatAction foreverAction = Actions.forever(repeatedAction);

		image.addAction(Paction);
		//image.addAction(foreverAction);
		//image.addAction(repeatedAction);

	}

7.在Render方法中进行舞台刷新

Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
stage.act();
stage.draw();

完整代码：

package com.mygdx.game;

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.InputProcessor;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.scenes.scene2d.Action;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.actions.Actions;
import com.badlogic.gdx.scenes.scene2d.actions.MoveToAction;
import com.badlogic.gdx.scenes.scene2d.actions.ParallelAction;
import com.badlogic.gdx.scenes.scene2d.actions.RepeatAction;
import com.badlogic.gdx.scenes.scene2d.actions.RotateToAction;
import com.badlogic.gdx.scenes.scene2d.actions.ScaleToAction;
import com.badlogic.gdx.scenes.scene2d.actions.SequenceAction;
import com.badlogic.gdx.scenes.scene2d.ui.Image;

/**
 * @author Administrator
 *
 */
public class MyGdxGame extends ApplicationAdapter implements InputProcessor {
	Texture starTexture;
	Texture ballTexture;
	Stage stage;
	Image image;

	@Override
	public void create() {
		stage = new Stage();
		starTexture = new Texture(Gdx.files.internal("study/action/star.png"));
		ballTexture = new Texture(Gdx.files.internal("study/action/ball.png"));
		Gdx.input.setInputProcessor(this);
	}

	@Override
	public void render() {
		Gdx.gl.glClearColor(0, 0, 0, 1);
		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
		stage.act();
		stage.draw();
	}

	public void setAction(final Image image) {
		float duration = MathUtils.random(1, 5);
		float scale = MathUtils.random(0.5f, 2.0f);
		float rotate = MathUtils.random(360);

		Action endAction = Actions.run(new Runnable() {
			@Override
			public void run() {
				System.out.println("All action is completed");
			}
		});

		MoveToAction moveto = Actions.moveTo(320, 240, duration);
		ScaleToAction scaleto = Actions.scaleTo(scale, scale, duration);
		RotateToAction rotateto = Actions.rotateTo(rotate, duration);
		SequenceAction alpha = Actions.sequence(Actions.fadeIn(duration),Actions.fadeOut(duration), endAction);
		ParallelAction Paction = Actions.parallel(moveto, scaleto, rotateto,alpha);
		RepeatAction repeatedAction = Actions.repeat(3, Paction);
		RepeatAction foreverAction = Actions.forever(repeatedAction);

		image.addAction(Paction);
		//image.addAction(foreverAction);
		//image.addAction(repeatedAction);

	}

	@Override
	public boolean touchDragged(int screenX, int screenY, int pointer) {
		createStar(MathUtils.randomBoolean(),
				screenX, 480 - screenY,MathUtils.random(10, 20));
		return false;
	}

	//利用随机boolean来随机创建ball或star
	private void createStar(boolean randomBoolean, int x, int y, int size) {
		if (randomBoolean == true) {
			image = new Image(starTexture);
		} else if (randomBoolean == false) {
			image = new Image(ballTexture);

		}
		this.setAction(image);
		image.setPosition(x - size / 2, y - size / 2);
		image.setSize(size, size);
		stage.addActor(image);
	}

	@Override
	public boolean keyDown(int keycode) {
		return false;
	}

	@Override
	public boolean keyUp(int keycode) {
		return false;
	}

	@Override
	public boolean keyTyped(char character) {
		return false;
	}

	@Override
	public boolean touchDown(int screenX, int screenY, int pointer, int button) {
		return false;
	}

	@Override
	public boolean touchUp(int screenX, int screenY, int pointer, int button) {
		return false;
	}

	@Override
	public boolean mouseMoved(int screenX, int screenY) {
		return false;
	}

	@Override
	public boolean scrolled(int amount) {
		return false;
	}
}