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();