30、自定义gridview

要想实现自定义gridview效果，有下边几个步骤：

1、定义grivew中的item的xml文件

假如item需要显示一个图片，图片下边显示文字：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="100dp"
 4     android:layout_height="100dp"
 5     android:orientation="vertical"
 6      >
 7     
 8     <Button
 9         android:id="@+id/button_gridview_item"
10         android:layout_width="130dp"
11         android:layout_height="130dp"
12         android:text=""
13         
14         android:focusable="false"
15         android:clickable="false"
16         
17         android:textColor="#ffffff"
18         android:textSize="36sp"
19         />
20     
21      <TextView
22         android:id="@+id/tv_login_staff_name"
23         android:layout_width="130dp"
24         android:layout_height="30dp"
25         android:text="button"
26         
27         android:focusable="false"
28         android:clickable="false"
29         android:textSize="15sp"
30         android:gravity="center"
31         android:textColor="#ffffff"
32         />
33     
34 </LinearLayout>

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2、自定义adapter

我是extends了baseAdapter,然后在getView时，将图片从网络加载到button上。

注意点：这些getItem、getItemId、getCount等继承过来的方法，一定要记得再次赋值

 1 public class login_gridview_adapter extends BaseAdapter{
 2     
 3     public static int selectPic = -1;
 4     private Context context = null;
 5     private  List<login_staff> list = null;
 6     private String tag = "adapter";
 7     
 8     public login_gridview_adapter(Context ctxt,List<login_staff> ls)
 9     {
10         for(int i=0;i<ls.size();i++)
11         {
12             CommonUtils.LogWuwei(tag,"in adaper "+ls.get(i).name );    
13         }
14         
15         context = ctxt;
16         list = ls;
17     }
18     
19     
20     
21     @Override
22     public int getCount() {
23         // TODO Auto-generated method stub
24         return list.size();
25     }
26 
27     public void setNotifyDataChange(int id) {
28         selectPic = id;
29         super.notifyDataSetChanged();
30     }
31     
32     @Override
33     public Object getItem(int position) {
34         // TODO Auto-generated method stub
35         return list.get(position);
36     }
37 
38     @Override
39     public long getItemId(int position) {
40         // TODO Auto-generated method stub
41         return position;
42     }
43 
44     @Override
45     public View getView(int position, View convertView, ViewGroup parent) {
46         // TODO Auto-generated method stub
47         
48         
49         CommonUtils.LogWuwei(tag, "position is "+position);
50         
51         LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
52         View grid = inflater.inflate(R.layout.grid_item, null);
53         
54         
55         if (convertView == null) {
56             grid = new View(context);
57             grid = inflater.inflate(R.layout.grid_item, null);
58             Button button = (Button) grid.findViewById(R.id.button_gridview_item);
59             String imgUrl = list.get(position).head;
60                 login.bitmapUtils.display(button, imgUrl, login.bigPicDisplayConfig, null);
61                 
62                 TextView tv = (TextView) grid.findViewById(R.id.tv_login_staff_name);
63                 tv.setText(list.get(position).name);
64             
65           } else {
66             grid = (View) convertView;
67           }
68         
69         if(selectPic == position)
70         {
71             String imgUrl = list.get(position).head;
72             //convertView.setAnimation(new AnimationUtils().loadAnimation(login.ctxt,R.anim.unzoom_in));
73             Message msg = new Message();
74             msg.what = login.REMOVE_GRIDVIEWS;
75             login.handler.sendMessage(msg);
76             login.bitmapUtils.display(login.gridviewStaffList, imgUrl, login.bigPicDisplayConfig, null);
77         }
78         return grid;
79     }
80 
81     
82 
83 }

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3、activity中设置gridview的适配器为我们上一步自定义的adapter

 1 gridviewStaffListAdapter = new login_gridview_adapter(ctxt, listLoginStaff);
 2 
 3 gridviewStaffList.setAdapter(gridviewStaffListAdapter);    
 4         gridviewStaffList.setSelector(new ColorDrawable(Color.TRANSPARENT));
 5         gridviewStaffList.setOnItemClickListener(new OnItemClickListener() {
 6 
 7             @Override
 8             public void onItemClick(AdapterView<?> parent, View view,
 9                     int position, long id) {
10                 // TODO Auto-generated method stub
11                 MsgUtils.SendSingleMsg(new HandlerUtils(ctxt).handler, listLoginStaff.get(position).name,HandlerUtils.SHOW_TOAST);
12                 gridviewStaffListAdapter.setNotifyDataChange(position);
13                 positionStaffId = listLoginStaff.get(position).staff_id;
14             }
15         });

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4、总结

要想改变gridview中数据，必须更新适配器（也就是设置过的adapter）；那么要想设置适配器，必须设置适配器定义时传入的list，list经过add、remove等操作后，要想让

gridview跟着改变，需要手动更新一下，比如说这样：

gridviewStaffListAdapter.notifyDataSetChanged();