Android 讲义第二版 ViewSwitcher + GestureDetector 练习

添加手势监听：

1     GestureDetector detector;// 手势侦听

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1 detector = new GestureDetector(getApplicationContext(),

2                 new myGestureListener());

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手势侦听 在 onFling 中指定屏幕滑动效果和展示图像：

 1 class myGestureListener implements OnGestureListener {

 2         // 当触碰事件按下时触发该方法

 3         @Override

 4         public boolean onDown(MotionEvent event) {

 5             return false;

 6         }

 7 

 8         // 用户在触摸屏上拖过时触发该方法

 9         @Override

10         public boolean onFling(MotionEvent event1, MotionEvent event2,

11                 float velocityX, float velocityY) {

12             ((GridView) viewSwitcher.getNextView()).setAdapter(adapter);

13             if (event2.getX() - event1.getX() > FLIP_DISTANCE) {

14                 if (screenNo > 0) {

15                     screenNo--;

16                     // 添加屏幕动画切换效果

17                     viewSwitcher.setInAnimation(animations[0]);

18                     viewSwitcher.setInAnimation(animations[3]);

19                     viewSwitcher.showPrevious();

20                     return true;

21                 } else {

22                     Toast.makeText(getApplicationContext(), "已无更多页面",

23                             Toast.LENGTH_LONG).show();

24                 }

25             } else {

26                 if (screenNo < screenCount - 1) {

27                     screenNo++;

28                     viewSwitcher.setInAnimation(animations[1]);

29                     viewSwitcher.setInAnimation(animations[2]);

30                     viewSwitcher.showNext();

31                     return true;

32                 } else {

33                     Toast.makeText(getApplicationContext(), "已无更多页面",

34                             Toast.LENGTH_LONG).show();

35                 }

36             }

37             return false;

38         }

39 

40         // 用户在屏幕上长按时触发该方法

41         @Override

42         public void onLongPress(MotionEvent event) {

43 

44         }

45 

46         // 用户在屏幕上滚动时触发该方法

47         @Override

48         public boolean onScroll(MotionEvent event1, MotionEvent event2,

49                 float velocityX, float velocityY) {

50             return false;

51         }

52 

53         // 用户在触摸屏上按下，而且还未移动和松开时触发该方法

54         @Override

55         public void onShowPress(MotionEvent arg0) {

56 

57         }

58 

59         // 用户在触屏上的轻击事件将触发该方法

60         @Override

61         public boolean onSingleTapUp(MotionEvent arg0) {

62             return false;

63         }

64 

65     }

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进入的第一个界面展示 代码：

 1 public void next(View v) {

 2         if (screenNo == -1) {

 3             screenNo++;

 4             ((GridView) viewSwitcher.getNextView()).setAdapter(adapter);

 5             viewSwitcher.showNext();

 6         } else {

 7             Toast.makeText(getApplicationContext(), "已无更多页面", Toast.LENGTH_LONG)

 8                     .show();

 9         }

10     }

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定义BaseAdapter：

 1 private BaseAdapter adapter = new BaseAdapter() {

 2         @Override

 3         public long getItemId(int position) {

 4             return position;

 5         }

 6 

 7         @Override

 8         public DataItem getItem(int position) {

 9             return total.get(screenNo * Number_Per_Screen + position);

10         }

11 

12         @Override

13         public int getCount() {

14             if (screenNo == screenCount - 1

15                     && total.size() % Number_Per_Screen != 0) {

16                 return total.size() % Number_Per_Screen;

17             }

18             return Number_Per_Screen;

19         }

20 

21         @Override

22         public View getView(int position, View convertView, ViewGroup parent) {

23             View view = convertView;

24             if (convertView == null) {

25                 view = layoutInflater.inflate(R.layout.labelicon, null);

26             }

27             ImageView imageview = (ImageView) view.findViewById(R.id.imageview);

28             imageview.setImageDrawable(getItem(position).drawable);

29             TextView textView = (TextView) view.findViewById(R.id.textview);

30             textView.setText(getItem(position).DataName);

31             return view;

32         }

33     };

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此处只是对 疯狂Android 讲义 中ViewSwitcher 的 手势 添加 做的一个小demo，本人处于初学阶段，如有不对的地方，请各位多多指正！！