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

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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

view
plain

<?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。

view
plain

<?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

view
plain

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

view
plain

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

view
plain

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 {

...

}

}

好了，来看运行结果



我选择了G2、G3、G11三项，现在屏幕滑动到底部，看以看到状态保存的很好，TextView显示已选中3项。全选、反选、取消已选功能正常，多选操作完美解决！