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：

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="100dp"
     android:layout_height="100dp"
     android:orientation="vertical"
      >

     <Button
         android:id="@+id/button_gridview_item"
         android:layout_width="130dp"
         android:layout_height="130dp"
         android:text=""

         android:focusable="false"
         android:clickable="false"

         android:textColor="#ffffff"
         android:textSize="36sp"
         />

      <TextView
         android:id="@+id/tv_login_staff_name"
         android:layout_width="130dp"
         android:layout_height="30dp"
         android:text="button"

         android:focusable="false"
         android:clickable="false"
         android:textSize="15sp"
         android:gravity="center"
         android:textColor="#ffffff"
         />

 </LinearLayout>

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

 public class login_gridview_adapter extends BaseAdapter{

     public static int selectPic = -1;
     private Context context = null;
     private  List<login_staff> list = null;
     private String tag = "adapter";

     public login_gridview_adapter(Context ctxt,List<login_staff> ls)
     {
         for(int i=0;i<ls.size();i++)
         {
             CommonUtils.LogWuwei(tag,"in adaper "+ls.get(i).name );
         }

         context = ctxt;
         list = ls;
     }

     @Override
     public int getCount() {
         // TODO Auto-generated method stub
         return list.size();
     }

     public void setNotifyDataChange(int id) {
         selectPic = id;
         super.notifyDataSetChanged();
     }

     @Override
     public Object getItem(int position) {
         // TODO Auto-generated method stub
         return list.get(position);
     }

     @Override
     public long getItemId(int position) {
         // TODO Auto-generated method stub
         return position;
     }

     @Override
     public View getView(int position, View convertView, ViewGroup parent) {
         // TODO Auto-generated method stub

         CommonUtils.LogWuwei(tag, "position is "+position);

         LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         View grid = inflater.inflate(R.layout.grid_item, null);

         if (convertView == null) {
             grid = new View(context);
             grid = inflater.inflate(R.layout.grid_item, null);
             Button button = (Button) grid.findViewById(R.id.button_gridview_item);
             String imgUrl = list.get(position).head;
                 login.bitmapUtils.display(button, imgUrl, login.bigPicDisplayConfig, null);

                 TextView tv = (TextView) grid.findViewById(R.id.tv_login_staff_name);
                 tv.setText(list.get(position).name);

           } else {
             grid = (View) convertView;
           }

         if(selectPic == position)
         {
             String imgUrl = list.get(position).head;
             //convertView.setAnimation(new AnimationUtils().loadAnimation(login.ctxt,R.anim.unzoom_in));
             Message msg = new Message();
             msg.what = login.REMOVE_GRIDVIEWS;
             login.handler.sendMessage(msg);
             login.bitmapUtils.display(login.gridviewStaffList, imgUrl, login.bigPicDisplayConfig, null);
         }
         return grid;
     }

 }

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

 gridviewStaffListAdapter = new login_gridview_adapter(ctxt, listLoginStaff);

 gridviewStaffList.setAdapter(gridviewStaffListAdapter);
         gridviewStaffList.setSelector(new ColorDrawable(Color.TRANSPARENT));
         gridviewStaffList.setOnItemClickListener(new OnItemClickListener() {

             @Override
             public void onItemClick(AdapterView<?> parent, View view,
                     int position, long id) {
                 // TODO Auto-generated method stub
                 MsgUtils.SendSingleMsg(new HandlerUtils(ctxt).handler, listLoginStaff.get(position).name,HandlerUtils.SHOW_TOAST);
                 gridviewStaffListAdapter.setNotifyDataChange(position);
                 positionStaffId = listLoginStaff.get(position).staff_id;
             }
         });

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();