实现ListView控件的多选和全选功能

实现ListView控件的多选和全选功能

 

主程序代码   MainActivity.java

package yy.test;

import java.util.ArrayList;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.CheckBox;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {
    private ListView listView;
    private MyAdapter adapter;
    private ArrayList<String> items;    //模拟存储信息的集合
    private ArrayList<String> checked;  //该集合存储被选中的列表项中的TextView中所显示的字符串
    private boolean isMultiple = false; // 记录是否是多选状态，true为是，false不是
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        listView = (ListView) findViewById(R.id.listview);
        items = new ArrayList<String>();
        items.add("00000");
        items.add("11111");
        items.add("22222");
        items.add("33333");
        items.add("44444");
        items.add("55555");
        items.add("66666");
        items.add("77777");
        items.add("88888");
        items.add("99999");
        items.add("aaaaa");
        items.add("bbbbb");
        items.add("ccccc");
        items.add("ddddd");
        adapter = new MyAdapter(items,this);  //new出自定义的MyAdapter对象
        listView.setAdapter(adapter);


        listView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View view, int position,
                    long arg3) {
                if(isMultiple){
                    CheckBox checkBox = (CheckBox) view.findViewById(R.id.checkbox);
                    TextView textView = (TextView) view.findViewById(R.id.text);
                    if(checkBox.isChecked()){
                        checkBox.setChecked(false);
                        adapter.checkedMap.put(position, false);
                        textView.setTextColor(Color.WHITE);
                        adapter.colorMap.put(position, Color.WHITE);
                        int index = checked.indexOf(textView.getText()+"");
                        checked.remove(index);

                    }else{
                        checkBox.setChecked(true);
                        adapter.checkedMap.put(position, true);
                        textView.setTextColor(Color.RED);
                        adapter.colorMap.put(position, Color.RED);
                        checked.add(textView.getText()+"");

                    }
                }
            }
        });
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        SubMenu subMenu = menu.addSubMenu("操作");
        subMenu.add(0, 1, 0, "多选");
        subMenu.add(0, 2, 0, "删除");
        subMenu.add(0, 3, 0, "全选");
        subMenu.add(0, 4, 0, "取消全选");
        return super.onCreateOptionsMenu(menu);
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if(item.getItemId()==1){
            isMultiple = true;
            checked = new ArrayList<String>();
            int index = adapter.getCount();
            for(int i=0;i<index;i++){
                adapter.visibleMap.put(i, CheckBox.VISIBLE);
            }
            adapter.notifyDataSetChanged();
        }else if(item.getItemId()==2){
            for(String text : checked){
                int index = items.indexOf(text);
                items.remove(index);

            }
            isMultiple = false;
            adapter = new MyAdapter(items,MainActivity.this);
            listView.setAdapter(adapter);

        }else if(item.getItemId()==3){
            isMultiple = true;
            checked = new ArrayList<String>();
            int index = adapter.getCount();
            for(int i=0;i<index;i++){
                adapter.checkedMap.put(i, true);
                adapter.colorMap.put(i, Color.RED);
                adapter.visibleMap.put(i, CheckBox.VISIBLE);
                View view1 = adapter.getView(i, null, null);
                TextView textView = (TextView) view1.findViewById(R.id.text);
                textView.setTextColor(Color.RED);
                /*CheckBox checkBox = (CheckBox) view1.findViewById(R.id.checkbox);
                checkBox.setVisibility(CheckBox.VISIBLE);*/
                adapter.notifyDataSetChanged();
                checked.add(textView.getText()+"");
            }

        }else if(item.getItemId()==4){
            isMultiple = false;
            checked = null;
            int index = adapter.getCount();
            for(int i=0;i<index;i++){
                adapter.checkedMap.put(i, false);
                adapter.colorMap.put(i, Color.WHITE);
                adapter.visibleMap.put(i, CheckBox.INVISIBLE);
                /*View view1 = adapter.getView(i, null, null);
                TextView textView = (TextView) view1.findViewById(R.id.text);
                textView.setTextColor(Color.WHITE);
                CheckBox checkBox = (CheckBox) view1.findViewById(R.id.checkbox);
                checkBox.setVisibility(CheckBox.INVISIBLE);*/
                adapter.notifyDataSetChanged();

            }
        }
        return super.onOptionsItemSelected(item);
    }
}

继承自BaseAdapter的MyAdapter

<pre class="java" name="code">package yy.test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.ImageView;
import android.widget.TextView;

public class MyAdapter extends BaseAdapter {

    private LayoutInflater inflater;
    private ArrayList<String> items;
    private Bitmap icon;
    private Context context;
    public Map<Integer,Boolean> checkedMap;   //保存checkbox是否被选中的状态
    public Map<Integer,Integer> colorMap;     //保存textview中文字的状态
    public Map<Integer,Integer> visibleMap;   //保存checkbox是否显示的状态

    public MyAdapter(ArrayList<String> items, Context context) {
        super();
        this.items = items;
        this.context = context;
        inflater = LayoutInflater.from(context);
        icon = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon);
        checkedMap = new HashMap<Integer, Boolean>();
        colorMap = new HashMap<Integer, Integer>();
        visibleMap = new HashMap<Integer, Integer>();
        for(int i=0;i<items.size();i++){
            checkedMap.put(i, false);
            colorMap.put(i, Color.WHITE);
            visibleMap.put(i, CheckBox.INVISIBLE);
        }
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return items.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }

    @Override
    public View getView(int position, View view, ViewGroup arg2) {
        view = inflater.inflate(R.layout.file_row, null);
        ImageView image = (ImageView) view.findViewById(R.id.icon);
        TextView text = (TextView) view.findViewById(R.id.text);
        CheckBox checkBox = (CheckBox) view.findViewById(R.id.checkbox);
        checkBox.setVisibility(visibleMap.get(position));
        checkBox.setChecked(checkedMap.get(position));
        image.setImageBitmap(icon);
        text.setText(items.get(position));
        text.setTextColor(colorMap.get(position));
        return view;
    }

}
</pre><br>
<pre></pre>
<pre class="java" name="code">主界面的布局文件</pre><pre class="java" name="code"><?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"
    >
    <ListView
    android:id="@+id/listview"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    />
</LinearLayout></pre><pre class="java" name="code"> </pre>
<p>MyAdapter中所使用的布局文件</p>
<pre class="java" name="code"><?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="horizontal"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_gravity="center_vertical"
  >
  <ImageView
  android:id="@+id/icon"
  android:layout_width="30dp"
  android:layout_height="30dp"
  android:layout_gravity="center_vertical"
  />
  <TextView
  android:id="@+id/text"
  android:layout_width="80dp"
  android:layout_height="wrap_content"
  android:layout_gravity="center_vertical"
  android:paddingLeft="5dp"
  />
  <CheckBox
  android:id="@+id/checkbox"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:focusable="false"
  android:clickable="false"
  android:focusableInTouchMode="false"

  />
</LinearLayout>
</pre>
<p> </p>
<p>下面来分析为什么要用map来保存checkbox以及textview的状态。<br>
<br>
这个与ListView的刷新机制有关，当你的listview对象很多的时候，每次你拖动listview上下滚动，listview都会刷新一次。怎么刷新呢？比如一个屏幕它最多只显示七条listview，如果你有十条数据，当你想看第八条时，第一条数据理所当然的要被隐藏掉，而第八条数据会被显示，这时listview就刷新了。如果你不保存你所选的checkbox的状态，这时如果你选的是第一条的checkbox的状态为true，当你把余下的第八、第九、第十条数据显示出来时，第十条的checkbox的状态会显示为true，但是它的状态没有被保存，只是你看到它是被选中了而已，其实你选的还是第一条数据。这个问题很操蛋。还有一个更离奇的状态，你让checkbox的状态为true，数据一定要大于十条，你不停的上下拖动屏幕，你会看见checkbox的显示状态会乱跳，但是你实际上选择的还是第一条数据，只是会让你的用户感觉很不爽罢了。<span style="font-family:Courier New; background-color:#f0f0f0"></span></p>
<pre class="java" name="code"></pre><p> </p>