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解决Android在listview添加checkbox实现单选多选操作问题

在Android某些开发需求当中，有时候需要在listveiw中加入checkbox实现单选，多选操作。表面上看上去只是改变checkbox那么简单，然而实际开发中，实现起来并不是那么得心应手。尤其当listview比较多(比如屏幕最多只能显示10个item，但总共有12个item，也就是说listview的 item数大于屏幕能够显示的item数)滑动屏幕的时候，由于适配器中getview()会重复使用被移除屏幕的item，所以会造成checkbox 选择状态不正常的现象。自己在开发中碰到这样的问题很是苦恼，查了下资料，发现网上很少没有针对这类批量操作并没有一个完整的例子。搜了很多篇帖子才完美的实现这一常用的操作。所以在这里把这个Demo贴出来，供大家参考，希望能对大家有所帮助。

主界面的布局main.xml 这个就不多说什么

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
         >
        <TextView
            android:id="@+id/tv"
            android:layout_width="fill_parent"
            android:layout_height="50dip"
            android:textColor="#FCFCFC"
            android:textSize="11pt"
            android:gravity="center_vertical"
            android:layout_marginLeft="10dip"
            /> 
    <ListView
        android:id="@+id/lv"
        android:layout_width="fill_parent"
        android:layout_height="381dip"
        android:cacheColorHint ="#00000000"
         ></ListView>
    </LinearLayout>
    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="53dip"
        android:orientation="horizontal"
        >
        <Button
            android:id="@+id/selectall"
            android:layout_width="80dip"  
            android:layout_height="50dip"
            android:layout_marginLeft="20dip"
            android:text="全选"
            android:gravity="center"
            />
        <Button
            android:id="@+id/inverseselect"
            android:layout_width="80dip"  
            android:layout_height="50dip"
            android:layout_marginLeft="118dip"
            android:text="反选"
            android:gravity="center"
            />
        <Button
            android:id="@+id/cancel"
            android:layout_width="80dip"  
            android:layout_height="50dip"
            android:layout_marginLeft="213dip"
            android:text="取消已选"
            android:gravity="center"
            />
    </RelativeLayout>
</LinearLayout>

ListView每个item的布局,listviewitem.xml：

这里需要注意的是，由于checkbox的点击事件优先级比listview的高，所以要添加android:focusable="false"属性，使得checkbox初始的时候没有获取焦点。

另外这里是点击ListView的item控制checkbox的状态改变，也就是让item接收clik事件，所以需要加上android:focusableInTouchMode="false"这一属性。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout  xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="55dip"
    android:orientation="horizontal"
    android:layout_marginTop="20dip"
    > 
    <TextView
        android:id="@+id/item_tv"
        android:layout_width="267dip"
        android:layout_height="40dip"
        android:textSize="10pt"
        android:gravity="center_vertical"
        android:layout_marginLeft="10dip"
        />
    <CheckBox
        android:id="@+id/item_cb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:focusable="false"  
        android:focusableInTouchMode="false"  
        android:clickable="false"
        android:layout_toRightOf="@id/item_tv" 
        android:layout_alignParentTop="true"
        android:layout_marginRight="5dip"
         
        />
</RelativeLayout >

ViewHolder类

package simtice.test.listview.viewholder;
import android.widget.CheckBox;
import android.widget.TextView;
  
public class ViewHolder {
    public TextView tv = null;
    public CheckBox cb = null;
}

为listview自定义适配器，该类为主Activity类MainActivity.java的内部类

public static class MyAdapter extends BaseAdapter {
        public static HashMap<Integer, Boolean> isSelected;
        private Context context = null;
        private LayoutInflater inflater = null;
        private List<HashMap<String, Object>> list = null;
        private String keyString[] = null;
        private String itemString = null; // 记录每个item中textview的值
        private int idValue[] = null;// id值
  
        public MyAdapter(Context context, List<HashMap<String, Object>> list,
                int resource, String[] from, int[] to) {
            this.context = context;
            this.list = list;
            keyString = new String[from.length];
            idValue = new int[to.length];
            System.arraycopy(from, 0, keyString, 0, from.length);
            System.arraycopy(to, 0, idValue, 0, to.length);
            inflater = LayoutInflater.from(context);
            init();
        }
  
        // 初始化 设置所有checkbox都为未选择
        public void init() {
            isSelected = new HashMap<Integer, Boolean>();
            for (int i = 0; i < list.size(); i++) {
                isSelected.put(i, false);
            }
        }
  
        @Override
        public int getCount() {
            return list.size();
        }
  
        @Override
        public Object getItem(int arg0) {
            return list.get(arg0);
        }
  
        @Override
        public long getItemId(int arg0) {
            return 0;
        }
  
        @Override
        public View getView(int position, View view, ViewGroup arg2) {
            ViewHolder holder = null;
            if (holder == null) {
                holder = new ViewHolder();
                if (view == null) {
                    view = inflater.inflate(R.layout.listviewitem, null);
                }
                holder.tv = (TextView) view.findViewById(R.id.item_tv);
                holder.cb = (CheckBox) view.findViewById(R.id.item_cb);
                view.setTag(holder);
            } else {
                holder = (ViewHolder) view.getTag();
            }
            HashMap<String, Object> map = list.get(position);
            if (map != null) {
                itemString = (String) map.get(keyString[0]);
                holder.tv.setText(itemString);
            }
            holder.cb.setChecked(isSelected.get(position));
            return view;
        }
  
    }

最后，最重要的就是MainActivity.java中一些事件响应的处理

public class MainActivity extends Activity {
    TextView tv = null;
    ListView lv = null;
    Button btn_selectAll = null;
    Button btn_inverseSelect = null;
    Button btn_calcel = null;
    String name[] = { "G1", "G2", "G3", "G4", "G5", "G6", "G7", "G8", "G9",
            "G10", "G11", "G12", "G13", "G14" };
      
    ArrayList<String> listStr = null;
    private List<HashMap<String, Object>> list = null;
    private MyAdapter adapter;
  
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        tv = (TextView) this.findViewById(R.id.tv);
        lv = (ListView) this.findViewById(R.id.lv);
        btn_selectAll = (Button) this.findViewById(R.id.selectall);
        btn_inverseSelect = (Button) this.findViewById(R.id.inverseselect);
        btn_calcel = (Button) this.findViewById(R.id.cancel);
        showCheckBoxListView();
          
        //全选
        btn_selectAll.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View arg0) {
                listStr = new ArrayList<String>();
                for(int i=0;i<list.size();i++){
                    MyAdapter.isSelected.put(i,true);
                    listStr.add(name[i]);
                }
                adapter.notifyDataSetChanged();//注意这一句必须加上，否则checkbox无法正常更新状态
                tv.setText("已选中"+listStr.size()+"项");
            }
        });
          
        //反选
        btn_inverseSelect.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                for(int i=0;i<list.size();i++){
                    if(MyAdapter.isSelected.get(i)==false){
                        MyAdapter.isSelected.put(i, true);
                        listStr.add(name[i]);
                    }
                    else{
                        MyAdapter.isSelected.put(i, false);
                        listStr.remove(name[i]);
                    }
                }
                adapter.notifyDataSetChanged();
                tv.setText("已选中"+listStr.size()+"项");
            }
              
        });
          
        //取消已选
        btn_calcel.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                for(int i=0;i<list.size();i++){
                    if(MyAdapter.isSelected.get(i)==true){
                        MyAdapter.isSelected.put(i, false);
                        listStr.remove(name[i]);
                    }
                }
                adapter.notifyDataSetChanged();
                tv.setText("已选中"+listStr.size()+"项");
            }
              
        });
    }
  
    // 显示带有checkbox的listview
    public void showCheckBoxListView() {
        list = new ArrayList<HashMap<String, Object>>();
        for (int i = 0; i < name.length; i++) {
            HashMap<String, Object> map = new HashMap<String, Object>();
            map.put("item_tv", name[i]);
            map.put("item_cb", false);
            list.add(map);
  
            adapter = new MyAdapter(this, list, R.layout.listviewitem,
                    new String[] { "item_tv", "item_cb" }, new int[] {
                            R.id.item_tv, R.id.item_cb });
            lv.setAdapter(adapter);
            listStr = new ArrayList<String>();
            lv.setOnItemClickListener(new OnItemClickListener() {
  
                @Override
                public void onItemClick(AdapterView<?> arg0, View view,
                        int position, long arg3) {
                    ViewHolder holder = (ViewHolder) view.getTag();
                    holder.cb.toggle();// 在每次获取点击的item时改变checkbox的状态
                    MyAdapter.isSelected.put(position, holder.cb.isChecked()); // 同时修改map的值保存状态
                    if (holder.cb.isChecked() == true) {
                        listStr.add(name[position]);
                    } else {
                        listStr.remove(name[position]);
                    }
                    tv.setText("已选中"+listStr.size()+"项");
                }
  
            });
        }
    }
  
    //为listview自定义适配器内部类
    public static class MyAdapter extends BaseAdapter {
        ...
    }
}