ListView的item选中效果
有时app会需要点击某个item并实现选中的效果,例如做pad时用Fragment实现的左侧列表右侧内容的效果,点击左侧某一个item后会高亮选中
有时简单的使用setSelected(boolean b)或setSelection(int position)会不成功,需要重写Adapter,并在getView中进行处理
package com.example.selectitemtest; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.Activity; import android.content.Context; import android.graphics.Color; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AbsListView; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends Activity { private ListView lv; private List<Map<String, Object>> data; private MyAdapter adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); lv = (ListView)findViewById(R.id.lv); //获取将要绑定的数据设置到data中 data = getData(); adapter = new MyAdapter(this); lv.setAdapter(adapter); lv.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE); lv.setOnItemClickListener(new ListView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { Toast.makeText(getApplicationContext(), "click position:"+arg2, Toast.LENGTH_SHORT).show(); adapter.setSelectedItem(arg2); //adapter.notifyDataSetInvalidated(); } }); } private List<Map<String, Object>> getData() { List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); Map<String, Object> map; for(int i=0;i<10;i++) { map = new HashMap<String, Object>(); map.put("img", R.drawable.ic_launcher); map.put("title", "花郎"); map.put("info", "动力源于兴趣..."); list.add(map); } return list; } //ViewHolder静态类 static class ViewHolder { public ImageView img; public TextView title; public TextView info; } public class MyAdapter extends BaseAdapter { private LayoutInflater mInflater = null; private int selectedItem = -1; private MyAdapter(Context context) { //根据context上下文加载布局,这里的是Demo17Activity本身,即this this.mInflater = LayoutInflater.from(context); } @Override public int getCount() { //How many items are in the data set represented by this Adapter. //在此适配器中所代表的数据集中的条目数 return data.size(); } @Override public Object getItem(int position) { // Get the data item associated with the specified position in the data set. //获取数据集中与指定索引对应的数据项 return position; } public void setSelectedItem(int selectedItem) { this.selectedItem = selectedItem; } @Override public long getItemId(int position) { //Get the row id associated with the specified position in the list. //获取在列表中与指定索引对应的行id return position; } //Get a View that displays the data at the specified position in the data set. //获取一个在数据集中指定索引的视图来显示数据 @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder = null; //如果缓存convertView为空,则需要创建View if(convertView == null) { holder = new ViewHolder(); //根据自定义的Item布局加载布局 convertView = mInflater.inflate(R.layout.list_item, null); holder.img = (ImageView)convertView.findViewById(R.id.img); holder.title = (TextView)convertView.findViewById(R.id.tv); holder.info = (TextView)convertView.findViewById(R.id.info); //将设置好的布局保存到缓存中,并将其设置在Tag里,以便后面方便取出Tag convertView.setTag(holder); }else { holder = (ViewHolder)convertView.getTag(); } holder.img.setBackgroundResource((Integer)data.get(position).get("img")); holder.title.setText((String)data.get(position).get("title")); holder.info.setText((String)data.get(position).get("info")); if(position == selectedItem) { //convertView.setBackgroundColor(Color.BLUE); //convertView.setSelected(true); convertView.setBackgroundResource(R.drawable.all_listentry_left_selected); }else { //convertView.setBackgroundColor(Color.GRAY); //convertView.setSelected(false); convertView.setBackgroundResource(R.drawable.lstview); } return convertView; } } }
代码中红色标注处就是重点,lv.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);这句话必须要加
Defines the choice behavior for the List. By default, Lists do not have any choice behavior (CHOICE_MODE_NONE
). By setting the choiceMode to CHOICE_MODE_SINGLE
, the List allows up to one item to be in a chosen state. By setting the choiceMode to CHOICE_MODE_MULTIPLE
, the list allows any number of items to be chosen.
实现效果如下
转自:http://www.cnblogs.com/loulijun/archive/2013/02/17/2914122.html