ListView详解5

五、本次要讲的是一个listview的进阶效果，主要实现的功能是，单击显示的item时，会显示出一个大图，以突出效果，即抽屉效果的ListView。效果如下所示：

其主要实现思路是：在getView的时候，动态修改布局，将选中的item添加新的View，这样就做到了点击的时候，与其他的item不同的效果。

代码如下：

public class MainActivity extends ListActivity {DrawListAdapter adapter;int[] imgs={R.drawable.image,R.drawable.packed,R.drawable.paste,R.drawable.text,R.drawable.delete};String[] text={"第一抽屉","第二抽屉","第三抽屉","第四抽屉","第五抽屉"};int currentItem=0;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        adapter = new DrawListAdapter(this);        //setListAdapter和getListView方法是ListActivity的方法，分别用于设置adapter和获得一个listview        this.setListAdapter(adapter);        this.getListView().setOnItemClickListener(new OnItemClickListener(){public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {// TODO Auto-generated method stubcurrentItem=arg2;//notifyDataSetChanged()可以在修改适配器绑定的数组后，不用重新刷新Activity，通知Activity更新ListViewadapter.notifyDataSetChanged();}        });    }        public class DrawListAdapter extends BaseAdapter{    Activity activity;    LayoutInflater inflater;        public DrawListAdapter(Activity a){    activity=a;    inflater=activity.getLayoutInflater();    }    public int getCount() {// TODO Auto-generated method stubreturn imgs.length;}public Object getItem(int arg0) {// TODO Auto-generated method stubreturn null;}public long getItemId(int position) {// TODO Auto-generated method stubreturn position;}public View getView(int position, View convertView, ViewGroup arg2) {// TODO Auto-generated method stubLinearLayout layout=new LinearLayout(activity);layout.setOrientation(LinearLayout.VERTICAL);layout.addView(addTitleView(position));if(currentItem==position){layout.addView(addCustomView(position));}return layout;}//获取选中项的内容private View addCustomView(int i) {// TODO Auto-generated method stubView view=new View(activity);ImageView iv=new ImageView(activity);//根据点击的position设置相应要显示的图片switch (i) {case 0:iv.setImageResource(R.drawable.ic_launcher);view=iv;break;case 1:iv.setImageResource(R.drawable.ic_launcher);view=iv;break;case 2:iv.setImageResource(R.drawable.ic_launcher);view=iv;break;case 3:iv.setImageResource(R.drawable.ic_launcher);view=iv;break;case 4:iv.setImageResource(R.drawable.ic_launcher);view=iv;break;}return view;}//获取list的标题内容private View addTitleView(int i) {// TODO Auto-generated method stubLinearLayout layout=new LinearLayout(activity);layout.setOrientation(LinearLayout.HORIZONTAL);ImageView iv=new ImageView(activity);iv.setImageResource(imgs[i]);layout.addView(iv,new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT));TextView tv=new TextView(activity);tv.setText(text[i]);layout.addView(tv,new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT));layout.setGravity(Gravity.CENTER);return layout;}        }}