android studio gridlayout拼图游戏（一）让图片完整显示

在慕课网上看到一个拼图游戏的视频，写了一个程序代码：

public class MainActivity extends AppCompatActivity {    private boolean gamestart=false;    private boolean isrun=false;    private ImageView[][] iv_game_arr=new ImageView[3][5];    private GridLayout game;    private ImageView nullimg;    private GestureDetector gestureDetector;    @Override    public boolean onTouchEvent(MotionEvent event) {        return gestureDetector.onTouchEvent(event);    }    @Override    public boolean dispatchTouchEvent(MotionEvent ev) {        gestureDetector.onTouchEvent(ev);        return super.dispatchTouchEvent(ev);    }    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        gestureDetector=new GestureDetector(this, new GestureDetector.OnGestureListener() {            @Override            public boolean onDown(MotionEvent motionEvent) {                return false;            }            @Override            public void onShowPress(MotionEvent motionEvent) {            }            @Override            public boolean onSingleTapUp(MotionEvent motionEvent) {                return false;            }            @Override            public boolean onScroll(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {                return false;            }            @Override            public void onLongPress(MotionEvent motionEvent) {            }            @Override            public boolean onFling(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {                int type=getGesture(motionEvent.getX(),motionEvent.getY(),motionEvent1.getX(),motionEvent1.getY());                changeGesture(type);                return true;            }        });        game=(GridLayout)findViewById(R.id.grid);        Bitmap bigm=((BitmapDrawable)getResources().getDrawable(R.drawable.pin)).getBitmap();        int tuW=bigm.getWidth()/5;        for (int i=0;i<iv_game_arr.length;i++){            for (int j=0;j<iv_game_arr[i].length;j++){                Bitmap bm=Bitmap.createBitmap(bigm,j*tuW,i*tuW,tuW,tuW);                iv_game_arr[i][j]=new ImageView(this);                iv_game_arr[i][j].setImageBitmap(bm);                iv_game_arr[i][j].setPadding(2,2,2,2);                iv_game_arr[i][j].setTag(new GameData(i,j,bm));                iv_game_arr[i][j].setOnClickListener(new View.OnClickListener() {                    @Override                    public void onClick(View view) {                        boolean flag=isNear((ImageView) view);//                        Toast.makeText(MainActivity.this,""+flag,Toast.LENGTH_SHORT).show();                        if (flag){                            Exchange((ImageView)view);                        }                    }                });            }        }        for (int i=0;i<iv_game_arr.length;i++) {            for (int j = 0; j < iv_game_arr[i].length; j++) {                GridLayout.LayoutParams p = new GridLayout.LayoutParams();                p.width = Resources.getSystem().getDisplayMetrics().widthPixels / 5;                p.height = p.width;                game.addView(iv_game_arr[i][j], p);            }        }        empty(iv_game_arr[2][4]);        random();        gamestart=true;    }    private void isGameOver(){        boolean isGameover=true;        for (int i=0;i<iv_game_arr.length;i++){            for (int j=0;j<iv_game_arr[i].length;j++){                if (iv_game_arr[i][j]==nullimg){                    continue;                }                GameData gameData=(GameData)iv_game_arr[i][j].getTag();                if (gameData.isTrue()){                    isGameover=false;                    break;                }            }        }        if (isGameover){            Toast.makeText(this,"over",Toast.LENGTH_SHORT).show();        }    }    private void random(){        for (int i=0;i<20;i++){            int type=(int)(Math.random()*4)+1;            changeGesture(type,false);        }    }    private void changeGesture(int type){        changeGesture(type,true);    }    private void changeGesture(int type,boolean isAnim){        GameData gameData=(GameData)nullimg.getTag();        int newx=gameData.x;        int newy=gameData.y;        if (type==1){            newx++;        }else if (type==2){            newx--;        }else if (type==3){            newy++;        }else if (type==4){            newy--;        }        if (newx>=0&&newx<iv_game_arr.length&&newy>=0&&newy<iv_game_arr[0].length){            if (isAnim){                Exchange(iv_game_arr[newx][newy]);            }else {                Exchange(iv_game_arr[newx][newy],isAnim);            }        }else {        }    }    //gesture 1:up;2:down;3:left;4:right    private int getGesture(float start_x,float start_y,float end_x,float end_y){        boolean isLeftorRight=(Math.abs(start_x-start_y)>Math.abs(start_y-end_y))?true:false;        if (isLeftorRight){            boolean isLeft=start_x-end_x>0?true:false;            if (isLeft){                return 3;            }else {                return 4;            }        }else {            boolean isUp=start_y-end_y>0?true:false;            if (isUp){                return 1;            }else {                return 2;            }        }    }    private void Exchange(final ImageView imageView){        Exchange(imageView,true);    }    private void Exchange(final ImageView imageView,boolean isAnim){        if (isrun){            return;        }        if (!isAnim){            GameData gameData=(GameData)imageView.getTag();            nullimg.setImageBitmap(gameData.bitmap);            GameData nullData=(GameData)nullimg.getTag();            nullData.bitmap=gameData.bitmap;            nullData.p_x=gameData.x;            nullData.p_y=gameData.y;            empty(imageView);            if (gamestart){                isGameOver();            }            return;        }        TranslateAnimation translateAnimation=null;        if (imageView.getX()>nullimg.getX()){            translateAnimation=new TranslateAnimation(0.1f,-imageView.getWidth(),0.1f,0.1f);        }else if (imageView.getX()<nullimg.getX()){            translateAnimation=new TranslateAnimation(0.1f,imageView.getWidth(),0.1f,0.1f);        }else if (imageView.getY()>nullimg.getY()){            translateAnimation=new TranslateAnimation(0.1f,0.1f,0.1f,-imageView.getHeight());        }else if (imageView.getY()<nullimg.getY()){            translateAnimation=new TranslateAnimation(0.1f,0.1f,0.1f,imageView.getHeight());        }        translateAnimation.setDuration(70);        translateAnimation.setFillAfter(true);        translateAnimation.setAnimationListener(new Animation.AnimationListener() {            @Override            public void onAnimationStart(Animation animation) {                isrun=true;            }            @Override            public void onAnimationEnd(Animation animation) {                isrun=false;                imageView.clearAnimation();                GameData gameData=(GameData)imageView.getTag();                nullimg.setImageBitmap(gameData.bitmap);                GameData nullData=(GameData)nullimg.getTag();                nullData.bitmap=gameData.bitmap;                nullData.p_x=gameData.x;                nullData.p_y=gameData.y;                empty(imageView);                if (gamestart){                    isGameOver();                }            }            @Override            public void onAnimationRepeat(Animation animation) {            }        });        imageView.startAnimation(translateAnimation);    }    private void empty(ImageView imageView){        imageView.setImageBitmap(null);        nullimg=imageView;    }    private Boolean isNear(ImageView imageView){        GameData nullgrid=(GameData)nullimg.getTag();        GameData normalgrid=(GameData)imageView.getTag();        if (nullgrid.y==normalgrid.y&&normalgrid.x+1==nullgrid.x){//upper than the empltygrid            return true;        }else if (nullgrid.y==normalgrid.y&&normalgrid.x==nullgrid.x+1){            return true;        }else if (nullgrid.y+1==normalgrid.y&&normalgrid.x==nullgrid.x){            return true;        }else if (nullgrid.y==normalgrid.y+1&&normalgrid.x==nullgrid.x){            return true;        }        return false;    }    //each grid data:x,y    class GameData{        private int x;        private int y;        private Bitmap bitmap;        private int p_x;        private int p_y;        private GameData(int x, int y,Bitmap bitmap) {            this.x = x;            this.y = y;            this.bitmap = bitmap;            this.p_x = x;            this.p_y = y;        }        private boolean isTrue(){            if (x==p_x&&y==p_y){                return true;            }            return false;        }    }}