Question

我对Android很新，我正在尝试为 listView 添加上下文菜单。所以我按照android开发者页面中显示的指南进行操作如果我长按 listView 中的项目，我会在操作栏中显示上下文菜单。我要添加的是，当我选择多个项目时，我想在上下文菜单中显示计数。此外，当我点击上下文菜单中的bin图标时，我喜欢删除所选项目。

我认为如果你看到我的代码会有点效率。下面是我的代码。它只是在开发者页面中描述

albumListView.setOnItemClickListener(this);
    albumListView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
    albumListView.setMultiChoiceModeListener(new MultiChoiceModeListener() {

        @Override
        public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
            // TODO Auto-generated method stub

            return false;
        }

        @Override
        public void onDestroyActionMode(ActionMode mode) {
            // TODO Auto-generated method stub

        }

        @Override
        public boolean onCreateActionMode(ActionMode mode, Menu menu) {
            // TODO Auto-generated method stub
            MenuInflater inflater = mode.getMenuInflater();
            inflater.inflate(R.menu.album_context_menu, menu);
            return true;
        }

        @Override
        public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public void onItemCheckedStateChanged(ActionMode mode, int position,
                long id, boolean checked) {
            // TODO Auto-generated method stub

        }
    });

如果你能提出一些建议，我会很高兴

Answer 1

MainActivity：

    package com.example.listviewexample;

    import java.util.ArrayList;

    import android.app.Activity;
    import android.graphics.Color;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.ActionMode;
    import android.view.Menu;
    import android.view.MenuInflater;
    import android.view.MenuItem;
    import android.view.ViewGroup;
    import android.widget.AbsListView.MultiChoiceModeListener;
    import android.widget.ListView;

    public class MainActivity extends Activity {

        ListView listViewObj;
        MyAdapter adapter;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            ArrayList<String> listArgument = new ArrayList<String>();
            listArgument.add("Item 1");
            listArgument.add("Item 2");
            listArgument.add("Item 3");
            listArgument.add("Item 4");
            listArgument.add("Item 5");
            listArgument.add("Item 6");
            listArgument.add("Item 7");
            Log.d("listArgument", listArgument.toString());
            listViewObj = (ListView) findViewById(R.id.list);
            adapter = new MyAdapter(this, listArgument);
            listViewObj.setAdapter(adapter);
            listViewObj.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
            listViewObj.setSelected(true);
            listViewObj.setMultiChoiceModeListener(new MultiChoiceModeListener() {
                int selectionCounter;

                @Override
                public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
                    // TODO Auto-generated method stub
                    return false;
                }

                @Override
                public void onDestroyActionMode(ActionMode mode) {
                    // TODO Auto-generated method stub

                }

                @Override
                public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                    // TODO Auto-generated method stub
                    MenuInflater inflater = getMenuInflater();
                    inflater.inflate(R.menu.main, menu);
                    return true;
                }

                @Override
                public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
                    // TODO Auto-generated method stub
                    switch (item.getItemId()) {
                    case R.id.action_delete:
                        selectionCounter = 0;
                        adapter.removeItem();
                        mode.finish();
                        return true;
                    default:
                        return false;
                    }

                }

                @Override
                public void onItemCheckedStateChanged(ActionMode mode,
                        int position, long id, boolean checked) {
                    if (checked) {
                        selectionCounter++;
                        adapter.selectedItem(position, position);

                    } else {
                        selectionCounter--;
                        adapter.removeSelection(position);  
                    }
                    mode.setTitle("Selected :" + selectionCounter);

                }
            });
        }
    }

适配器类：

            package com.example.listviewexample;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

import android.content.Context;
import android.graphics.Color;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class MyAdapter extends BaseAdapter{
    HashMap<Integer,Integer> selectionValueMap = new HashMap<Integer,Integer>();
    Context vContext;
    ArrayList<String> DataValueList = new ArrayList<String>();
    public MyAdapter(Context context,ArrayList<String> DataValueList)
    {
        this.vContext = context;
        this.DataValueList = DataValueList;
    }


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

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return DataValueList.get(position);
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }
    public void selectedItem(int postion ,int flag)
    {
        selectionValueMap.put(postion, flag);
        notifyDataSetChanged();
    }
    public void removeSelection(int position)
    {
        selectionValueMap.remove(position);
        notifyDataSetChanged();
    }
    public void removeItem()
    {
        Set<Integer> mapKeySet = selectionValueMap.keySet();
        Iterator keyIterator = mapKeySet.iterator();
        while(keyIterator.hasNext())
        {
            int key = (Integer) keyIterator.next();
            Log.d("key", Integer.toString(key));
            DataValueList.remove(key);
            //DataValueList.remove(selectionValueMap.get(key));
        }
        notifyDataSetChanged();
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LayoutInflater mInflater = (LayoutInflater)     vContext.getSystemService(vContext.LAYOUT_INFLATER_SERVICE);
        convertView = mInflater.inflate(R.layout.list_item, null);
        TextView tx = (TextView)convertView.findViewById(R.id.textView1);
        tx.setText(DataValueList.get(position));

        if(selectionValueMap.get(position) != null)
        {
            tx.setBackgroundColor(Color.GREEN);//Choose Any Color
        }
        return convertView;
    }


}

在android上下文菜单中添加多个选择和删除功能

1 个答案: