diff --git a/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseAdapter.java b/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseAdapter.java
index 7689cac..41f322f 100755
--- a/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseAdapter.java
+++ b/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseAdapter.java
@@ -23,7 +23,7 @@
  * <br> 适用于几乎所有列表、表格，包括：
  * <br> 1.RecyclerView及其子类
  * <br> 2.ListView,GridView等AbsListView的子类
- * <br> 3.RecyclerView刷新用 refresh 或 notifyDataSetChanged; AbsListView刷新用 refresh 或 notifyListDataSetChanged
+ * <br> 3.刷新用 refresh 或 notifyListDataSetChanged，notifyDataSetChanged 可能无效
  * <br> 4.出于性能考虑，里面很多方法对变量(比如list)都没有判断，应在adapter外判断
  * @author SCWANG
  * @author Lemon
@@ -91,23 +91,41 @@ public void setOnLoadListener(OnLoadListener onLoadListener) {
      * <br > > 0 - 列表滚到倒数第preloadCount个Item View显示时加载更多
      * @use 可在子类getView被调用前(可以是在构造器内)赋值
      */
-    protected int preloadCount = 0;
+    public int preloadCount = 0;
+
 
     //预加载，可不使用 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
 
 
+
+
+
     /**bv的显示方法
      * @param position
      * @param bv
      */
     @Override
     public void bindView(int position, BV bv) {
+        bv.selected = isSelected(position);
         bv.bindView(getItem(position), position, getItemViewType(position));
         if (SettingUtil.preload && onLoadListener != null && position >= getCount() - 1 - preloadCount) {
             onLoadListener.onLoadMore();
         }
     }
 
+    /**
+     * 已选中项的位置，一般可在onItemClick回调中：
+     * <br /> adapter.selectedPosition = position;
+     * <br /> adapter.notifyListDataSetChanged();
+     */
+    public int selectedPosition = -1;
+    /**是否已被选中，默认实现单选，重写可自定义实现多选
+     * @param position
+     * @return
+     */
+    public boolean isSelected(int position) {
+        return selectedPosition == position;
+    }
 
 
 
@@ -122,14 +140,12 @@ public List<T> getList() {
      */
     public synchronized void refresh(List<T> list) {
         this.list = list == null ? null : new ArrayList<T>(list);
-        notifyDataSetChanged(); //仅对 RecyclerView 有效
         notifyListDataSetChanged(); //仅对 AbsListView 有效
     }
 
 
-
-
     //RecyclerAdapter <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+
     @Override
     public BV onCreateViewHolder(final ViewGroup parent, int viewType) {
         final BV bv = createView(viewType, parent);
@@ -195,9 +211,9 @@ public void unregisterDataSetObserver(DataSetObserver observer) {
     /**
      * Notifies the attached observers that the underlying data has been changed
      * and any View reflecting the data set should refresh itself.
-     * 仅对 AbsListView 有效
      */
     public void notifyListDataSetChanged() {
+        notifyDataSetChanged(); //仅对 RecyclerView 有效
         mDataSetObservable.notifyChanged();
     }
 
diff --git a/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseView.java b/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseView.java
index fe46d10..134ea12 100755
--- a/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseView.java
+++ b/ZBLibrary(AndroidStudio)/ZBLibrary/src/main/java/zuo/biao/library/base/BaseView.java
@@ -157,6 +157,10 @@ public <V extends View> V findViewById(int id, OnClickListener listener) {
 	 * 视图类型，部分情况下需要根据viewType使用不同layout，对应Adapter的itemViewType
 	 */
 	public int viewType = 0;
+	/**
+	 * 是否已被选中
+	 */
+	public boolean selected = false;
 
 	/**创建一个新的View
 	 * @return
@@ -204,6 +208,8 @@ public void bindView(T data_) {
 			Log.w(TAG, "bindView data_ == null");
 		}
 		this.data = data_;
+
+		//不一定要用单选功能，实现也不一定要用这种方式，这里写会影响所有BaseView子类的性能，子类写更好 itemView.setSelected(selected);
 	}
 
 	/**获取可见性
diff --git a/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoListFragment.java b/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoListFragment.java
index 610924d..87648b9 100644
--- a/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoListFragment.java
+++ b/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoListFragment.java
@@ -151,6 +151,10 @@ public void initEvent() {//必须在onCreateView方法内调用
 	//示例代码<<<<<<<<<<<<<<<<<<<
 	@Override
 	public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+		//实现单选
+		adapter.selectedPosition = adapter.selectedPosition == position ? -1 : position;
+		adapter.notifyListDataSetChanged();
+
 		toActivity(UserActivity.createIntent(context, position));//一般用id，这里position仅用于测试 id));//
 	}
 	//示例代码>>>>>>>>>>>>>>>>>>>
diff --git a/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoView.java b/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoView.java
index a3d7970..f8b4beb 100755
--- a/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoView.java
+++ b/ZBLibrary(AndroidStudio)/app/src/main/java/zblibrary/demo/DEMO/DemoView.java
@@ -15,7 +15,6 @@
 package zblibrary.demo.DEMO;
 
 import android.app.Activity;
-import android.util.Log;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
@@ -72,13 +71,11 @@ public View createView() {
 
 
 	@Override
-	public void bindView(Entry<String, String> data){
+	public void bindView(Entry<String, String> data_){
 		//示例代码<<<<<<<<<<<<<<<<
-		if (data == null) {
-			Log.e(TAG, "bindView data == null >> data = new Entry<>(); ");
-			data = new Entry<String, String>();
-		}
-		this.data = data;
+		super.bindView(data_ != null ? data_ : new Entry<String, String>());
+
+		itemView.setBackgroundResource(selected ? R.drawable.alpha3 : R.drawable.white_to_alpha);
 
 		tvDemoViewName.setText(StringUtil.getTrimedString(data.getKey()));
 		tvDemoViewNumber.setText(StringUtil.getTrimedString(data.getValue()));