Android开发学习之路-下拉刷新以及GridView的使用

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     tools:context="com.example.girdlayoutdemo.MainActivity" >
 6 
 7     <ProgressBar
 8         android:id="@+id/pb"
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content"
11         android:layout_centerHorizontal="true" />
12 
13     <GridView
14         android:layout_below="@id/pb"
15         android:id="@+id/gv"
16         android:layout_width="match_parent"
17         android:layout_height="match_parent"
18         android:layout_margin="5dp"
19         android:gravity="center"
20         android:numColumns="2" >
21     </GridView>
22 
23 </RelativeLayout>

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" >
 6 
 7     <ImageView
 8         android:id="@+id/item_iv"
 9         android:layout_width="fill_parent"
10         android:layout_height="0dp"
11         android:layout_weight="3" />
12 
13     <TextView
14         android:id="@+id/item_tv"
15         android:layout_width="match_parent"
16         android:layout_height="0dp"
17         android:layout_weight="1" />
18 
19 </LinearLayout>

  1 public class MainActivity extends Activity {
  2     private GridView gv;
  3     private ProgressBar pb;
  4     private List<Map<String, Object>> list;
  5     private SimpleAdapter adapter;
  6     private GestureDetector gsDetector;
  7 
  8     private Handler handler = new Handler() {
  9         @Override
 10         public void handleMessage(Message msg) {
 11             switch (msg.what) {
 12             case 1:
 13                 pb.setVisibility(View.GONE);
 14                 Toast.makeText(MainActivity.this, "刷新成功", 200).show();
 15                 break;
 16             default:
 17                 break;
 18             }
 19         }
 20     };
 21 
 22     @Override
 23     protected void onCreate(Bundle savedInstanceState) {
 24         super.onCreate(savedInstanceState);
 25         setContentView(R.layout.activity_main);
 26         pb = (ProgressBar) findViewById(R.id.pb);
 27         gv = (GridView) findViewById(R.id.gv);
 28         pb.setVisibility(View.GONE);
 29         initData();
 30         adapter = new SimpleAdapter(this, list, R.layout.item_layout,
 31                 new String[] { "image", "text" }, new int[] { R.id.item_iv,
 32                         R.id.item_tv });
 33         gv.setAdapter(adapter);
 34         gsDetector = new GestureDetector(this, new Mlistener());
 35         gv.setOnTouchListener(new OnTouchListener() {
 36 
 37             @Override
 38             public boolean onTouch(View v, MotionEvent event) {
 39                 // Log.e("MainActivity", event.getX()+"");
 40                 return gsDetector.onTouchEvent(event);
 41             }
 42         });
 43     }
 44 
 45     private void initData() {
 46         list = new ArrayList<Map<String, Object>>();
 47         for (int i = 0; i < 20; i++) {
 48             Map<String, Object> map = new HashMap<String, Object>();
 49             map.put("image", R.drawable.gift_item_default);
 50             map.put("text", "一只冰莹猪猪");
 51             list.add(map);
 52         }
 53     }
 54 
 55     class Mlistener implements OnGestureListener {
 56 
 57         @Override
 58         public boolean onDown(MotionEvent e) {
 59             return false;
 60         }
 61 
 62         @Override
 63         public void onShowPress(MotionEvent e) {
 64 
 65         }
 66 
 67         @Override
 68         public boolean onSingleTapUp(MotionEvent e) {
 69             return false;
 70         }
 71 
 72         @Override
 73         public boolean onScroll(MotionEvent e1, MotionEvent e2,
 74                 float distanceX, float distanceY) {
 75             return false;
 76         }
 77 
 78         @Override
 79         public void onLongPress(MotionEvent e) {
 80 
 81         }
 82 
 83         @Override
 84         public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
 85                 float velocityY) {
 86             if (e2.getY() - e1.getY() > 0 && gv.getFirstVisiblePosition() == 0) {
 87                 pb.setVisibility(View.VISIBLE);
 88                 Animation animation = new ScaleAnimation(1f, 1f, 0, 1f);
 89                 animation.setDuration(300);
 90                 pb.startAnimation(animation);
 91 
 92                 new Thread(new Runnable() {
 93                     @Override
 94                     public void run() {
 95                         try {
 96                             Thread.sleep(2000);
 97                             Message msg = new Message();
 98                             msg.what = 1;
 99                             handler.sendMessage(msg);
100                         } catch (InterruptedException e) {
101                             // TODO Auto-generated catch block
102                             e.printStackTrace();
103                         }
104                     }
105                 }).start();
106 
107             }
108             return false;
109         }
110 
111     }
112 
113 }