使用ListAdapter是ListView的适配器。
使用ListView.setAdapter()方法来设置ListView的适配器。
- 简单的使用
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1); adapter.add("hello"); adapter.add("eoe"); lv.setAdapter(adapter); |
R前面的android表示使用的是系统提供给我们的资源。
- 使用自定义的资源
在layout包下新建一个XML,内容如下:
<?xml <ListView android:layout_width="match_parent" android:layout_height="match_parent" </ListView> |
然后如下所示,创建Adapter:
adapter = new ArrayAdapter<String>(this,R.layout.list_cell_view); adapter.add("hello"); adapter.add("eoe"); lv.setAdapter(adapter); |
- 自定义Adapter
private BaseAdapter adapter = new BaseAdapter() { private String[] data = {"user1","user2","user3","user4","user5","user6", "user7","user8","user9","user10","user11","user12","user13","user14",}; @Override public View getView(int position, View convertView, ViewGroup parent) { TextView tv = new TextView(MainActivity.this); tv.setText(getItem(position)); return tv; }
@Override public return position; }
@Override public String getItem(int position) { return }
@Override public return } }; |
程序运行时,界面上显示多少个列表项,getView方法就是被执行多少次。
getView参数中的View表示被系统回收的View。
优化:
TextView tv = null; if (convertView!=null){ tv = (TextView) convertView; }else { tv = new TextView(MainActivity.this); } tv.setText(getItem(position)); |
- 创建一个可以显示图片的ListView
在layout中新建一个Linearlayout布局的文件:
<?xml <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent"
<ImageView android:layout_width="120dp" android:layout_height="120dp" android:id="@+id/icon"/> <LinearLayout android:layout_weight="1" android:layout_width="0dp" android:layout_height="match_parent" android:orientation="vertical"> <TextView android:id="@+id/name" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/dec" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </LinearLayout>
</LinearLayout> |
创建一个Adapter:
private BaseAdapter adapter = new BaseAdapter() { private ListCellData[] data = new ListCellData[]{ new ListCellData("小明", "男", android.R.drawable.ic_btn_speak_now), new ListCellData("小丽", "女", android.R.drawable.ic_dialog_dialer), }; @Override public View getView(int position, View convertView, ViewGroup parent) { LinearLayout line = null; if (convertView!=null){ line = (LinearLayout) convertView; }else { line = (LinearLayout) LayoutInflater.from(MainActivity.this).inflate(R.layout.list_cell_view, null); } ListCellData item = getItem(position); ImageView image = (ImageView) line.findViewById(R.id.icon); TextView name = (TextView) line.findViewById(R.id.name); TextView dec = (TextView) line.findViewById(R.id.dec); image.setImageResource(item.getIcon()); name.setText(item.getUsername()); dec.setText(item.getSex()); return line; }
@Override public return position; }
@Override public ListCellData getItem(int position) { return }
@Override public return } }; |