解決Android在listview添加checkbox實現單選多選操作問題

轉自： http://blog.csdn.net/failure01/article/details/8561573

在Android某些開發需求當中，有時候需要在listveiw中加入checkbox實現單選，多選操作。表面上看上去只是改變checkbox那麼簡單，然而實際開發中，實現起來並不是那麼得心應手。尤其當listview比較多(比如屏幕最多隻能顯示10個item，但總共有12個item，也就是說listview的item數大於屏幕能夠顯示的item數)滑動屏幕的時候，由於適配器中getview()會重複使用被移除屏幕的item，所以會造成checkbox選擇狀態不正常的現象。自己在開發中碰到這樣的問題很是苦惱，查了下資料，發現網上很少沒有針對這類批量操作並沒有一個完整的例子。搜了很多篇帖子才完美的實現這一常用的操作。所以在這裏把這個Demo貼出來，供大家參考，希望能對大家有所幫助。

主界面的佈局main.xml    這個就不多說什麼

<?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="全選"
            android:gravity="center"
            />
        <Button
            android:id="@+id/inverseselect"
            android:layout_width="80dip"
            android:layout_height="50dip"
            android:layout_marginLeft="118dip"
            android:text="反選"
            android:gravity="center"
            />
        <Button
            android:id="@+id/cancel"
            android:layout_width="80dip"
            android:layout_height="50dip"
            android:layout_marginLeft="213dip"
            android:text="取消已選"
            android:gravity="center"
            />
    </RelativeLayout>
</LinearLayout>

ListView每個item的佈局,listviewitem.xml：


這裏需要注意的是，由於checkbox的點擊事件優先級比listview的高，所以要添加Android:focusable="false"屬性，使得checkbox初始的時候沒有獲取焦點。


另外這裏是點擊ListView的item控制checkbox的狀態改變，也就是讓item接收clik事件，所以需要加上android:focusableInTouchMode="false"這一屬性。

<?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類

package simtice.test.listview.viewholder;
import Android.widget.CheckBox;
import android.widget.TextView;

public class ViewHolder {
    public TextView tv = null;
    public CheckBox cb = null;
}

爲listview自定義適配器，該類爲主Activity類MainActivity.java的內部類

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; // 記錄每個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 設置所有checkbox都爲未選擇
        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 = 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);
            }
            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;
        }

    }

最後，最重要的就是MainActivity.java中一些事件響應的處理

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();

        //全選
        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();//注意這一句必須加上，否則checkbox無法正常更新狀態
                tv.setText("已選中"+listStr.size()+"項");
            }
        });

        //反選
        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("已選中"+listStr.size()+"項");
            }

        });

        //取消已選
        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("已選中"+listStr.size()+"項");
            }

        });
    }

    // 顯示帶有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();// 在每次獲取點擊的item時改變checkbox的狀態
                    MyAdapter.isSelected.put(position, holder.cb.isChecked()); // 同時修改map的值保存狀態
                    if (holder.cb.isChecked() == true) {
                        listStr.add(name[position]);
                    } else {
                        listStr.remove(name[position]);
                    }
                    tv.setText("已選中"+listStr.size()+"項");
                }

            });
        }
    }

    //爲listview自定義適配器內部類
    public static class MyAdapter extends BaseAdapter {
        ...
    }
}

結果如下