我在工作中發現：觸碰模式下的listview項無法被選中，所謂選中，意思是點擊選中該項後，背景長期高亮。
在模擬器上測試時，可以使用鼠標滑輪滾動選中，這會調用onItemSelected()方法，在這裏可以設置選中項高亮。
在真機上，由於沒有滑輪，只能用手指點擊選中，但是點擊時，不會有選中後高亮的效果（注意：選中後高亮不是指點擊選中那一下高亮，而是點擊後長期高亮）。
或許你會想到使用selector背景選擇器來設置：
<?xml version="1.0" encoding="utf-8" ?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<!-- 默認時的背景圖片-->
<item android:drawable="@drawable/pic1" />
<!-- 沒有焦點時的背景圖片-->
<item android:state_window_focused="false" android:drawable="@drawable/pic1" />
<!-- 非觸摸模式下獲得焦點並單擊時的背景圖片-->
<item android:state_focused="true" android:state_pressed="true"
android:drawable="@drawable/pic2" />
<!-- 觸摸模式下單擊時的背景圖片-->
<item android:state_focused="false" android:state_pressed="true"
android:drawable="@drawable/pic3" />
<!--選中時的圖片背景-->
<item android:state_selected="true" android:drawable="@drawable/pic4" />
<!--獲得焦點時的圖片背景-->
<item android:state_focused="true" android:drawable="@drawable/pic5" />
</selector>
於是我只能在java代碼中尋求思路了
下面的代碼實現listview單選模式下點擊後背景圖片長期高亮
package org.yaoming.listview;
import org.yaoming.util.Common;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
public class Listview_selectorActivity extends Activity implements OnItemClickListener {
private String[] arrays;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
arrays = new String[] {"a","b","c","d","e"};
//使用SharedPreferences是爲了每次點擊退出時都保存之前選中的項，以後一打開時就可以看到以前的選擇
SharedPreferences sp = getSharedPreferences("testListview", 0);
Common.SELECTED = sp.getInt("selected", Common.SELECTED);
ListView listview = (ListView) findViewById(R.id.listView1);
listview.setAdapter(new MyAdapter(this));
listview.setOnItemClickListener(this);
}
public class MyAdapter extends BaseAdapter{
Context context;
public class ViewHolder{
TextView tv;
ImageView iv;
}
public MyAdapter(Context context){
this.context = context;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return arrays.length;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
//通過日誌測試，原來每次點擊listview的每一項，這裏都會運行
//通過查看源碼，原來是getItemAtPosition()中getAdapter()搞的鬼
Log.i("listview", "zhixingguo ");
LinearLayout layout;
ViewHolder viewholder;
if(null == convertView){
layout = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.item, null);
viewholder = new ViewHolder();
viewholder.tv = (TextView) layout.findViewById(R.id.textView2);
viewholder.iv = (ImageView) layout.findViewById(R.id.imageView1);
convertView = layout;
layout.setTag(viewholder);
}else{
layout = (LinearLayout) convertView;
viewholder = (ViewHolder) layout.getTag();
}
viewholder.tv.setText(arrays[position]);
//在這裏加個判斷，若爲選中項，則改變背景圖片和背景色
if(Common.SELECTED == position){
viewholder.iv.setBackgroundResource(R.drawable.asi);
layout.setBackgroundResource(R.color.blue);
}else {
viewholder.iv.setBackgroundResource(R.drawable.icon);
layout.setBackgroundResource(R.color.transparent);
}
return convertView;
}
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
//如果在這裏簡單地通過findviewbyid()改變背景圖片，點擊時會出現圖片亂顯示的情況
// ImageView iv = (ImageView) view.findViewById(R.id.imageView1);
// iv.setImageResource(R.drawable.asi);
//改變SELECTED的值，並在getview裏判斷加載的位置是否爲選中的位置
Common.SELECTED = position;
}
}還有一個自定義的util類
package org.yaoming.util;
public class Common {
public static int SELECTED = -1;
}
另外，main.xml的代碼：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content" android:text="@string/hello" />
<ListView android:id="@+id/listView1" android:choiceMode="singleChoice"
android:cacheColorHint="#00000000" android:layout_height="wrap_content"
android:layout_width="match_parent"></ListView>
</LinearLayout>listview的item佈局：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:text="TextView"
android:id="@+id/textView2" android:textSize="30sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></TextView>
<ImageView android:src="@drawable/icon"
android:layout_width="wrap_content" android:id="@+id/imageView1"
android:layout_height="wrap_content"></ImageView>
</LinearLayout>不使用selector，直接在java代碼裏設置。在onItemClick的時候獲得position，並在getview判斷是否爲選中項，設置背景顏色高亮，記得佈局文件中listview要設置成singleChoiceMode。
值得注意的是，onItemClick會觸發getItemAtPosition方法
/**
* Callback method to be invoked when an item in this AdapterView has
* been clicked.
* <p>
* Implementers can call getItemAtPosition(position) if they need
* to access the data associated with the selected item.
*
* @param parent The AdapterView where the click happened.
* @param view The view within the AdapterView that was clicked (this
* will be a view provided by the adapter)
* @param position The position of the view in the adapter.
* @param id The row id of the item that was clicked.
*/
void onItemClick(AdapterView<?> parent, View view, int position, long id);
}而getItemAtPosition又會調用getAdapter方法，就相當於重新刷新一次ui中的listview
/**
* Gets the data associated with the specified position in the list.
*
* @param position Which data to get
* @return The data associated with the specified position in the list
*/
public Object getItemAtPosition(int position) {
T adapter = getAdapter();
return (adapter == null || position < 0) ? null : adapter.getItem(position);
}實現效果如下：
第一次寫技術博客，多有差池請多多指教，如有說不清楚的地方，請賜教。
下面是源碼下載地址
http://download.csdn.net/detail/iamkila/4034770
