1 public class ActionTestScreen implements Screen,InputProcessor{ 2     private Stage stage; 3     private Texture texture; 4     private Image img; 5  6     @Override 7     public void render(float delta) { 8         Gdx.gl.glClearColor(1, 0, 0, 1); 9         Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);10         stage.act();11         stage.draw();12     }13 14     @Override15     public void show() {16         Gdx.input.setInputProcessor(this);//容易遗忘17         stage = new Stage();18         texture = new Texture("badlogic.jpg");19         img = new Image(texture);20         //img.setCenterPosition(img.getWidth()/2,img.getHeight()/2);//重要21         img.setOrigin(img.getCenterX(),img.getCenterY());//重要！22         stage.addActor(img);23         System.out.println(img.getX()+","+img.getY());24     }25 26     @Override27     public boolean keyDown(int keycode) {28         switch (keycode){29             case Input.Keys.NUM_1:{30                 MoveByAction moveBy = Actions.moveBy(100,100,0.5f);31                 img.addAction(moveBy);32                 return true;33             }34             case Input.Keys.NUM_2:{35                 MoveToAction moveTo = Actions.moveTo(200, 200, 0.5f);36                 img.addAction(moveTo);37                 return true;38             }39             case Input.Keys.NUM_3:{40                 RotateByAction rotateBy = Actions.rotateBy(90,0.5f);41                 img.addAction(rotateBy);42                 return true;43             }44             case Input.Keys.NUM_4:{45                 RotateToAction rotateTo = Actions.rotateTo(90, 0.5f);46                 img.addAction(rotateTo);47                 return true;48             }49             case Input.Keys.NUM_5:{50                 ScaleByAction scaleBy = Actions.scaleBy(0.5f,0.5f,0.5f);51                 img.addAction(scaleBy);52                 return true;53             }54             case Input.Keys.NUM_6:{55                 ScaleToAction scaleTo = Actions.scaleTo(0.5f,0.5f,0.5f);56                 img.addAction(scaleTo);57                 return true;58             }59             case Input.Keys.NUM_7:{//顺序执行60                 img.setCenterPosition(0,0);61                 img.setScale(1,1);62 63                 MoveToAction m2 = Actions.moveTo(200,200,0.5f);64                 RotateByAction r1 = Actions.rotateBy(360,0.5f);65                 ScaleToAction s1 = Actions.scaleTo(0.5f,0.5f,0.5f);66                 SequenceAction s = Actions.sequence(m2,r1,s1);67                 img.addAction(s);68                 return true;69             }70             case Input.Keys.NUM_8:{//同时执行71                 img.setCenterPosition(0,0);72                 img.setScale(1,1);73 74                 MoveToAction m2 = Actions.moveTo(200,200,0.5f);75                 RotateByAction r1 = Actions.rotateBy(360,0.5f);76                 ScaleToAction s1 = Actions.scaleTo(0.5f,0.5f,0.5f);77                 ParallelAction s = Actions.parallel(m2,r1,s1);78                 img.addAction(s);79                 return true;80             }81             case Input.Keys.A:{//同时执行82                 AlphaAction a1 = Actions.alpha(0.5f,0.5f);83 84                 img.addAction(a1);85                 return true;86             }87             ......88 89 90         }91         return false;92     }93 ......