在android上下文菜单中添加多个选择和删除功能

Question

我对 android 很陌生，我正在尝试为我的 listView 添加 context menu。所以我按照 android 开发者页面中显示的指南进行操作，现在如果我从我的 listView 中长按一个项目我得到 context menu 出现在操作栏中。我要补充的是，当我选择超过 1 个项目时，我想在 context menu 中显示 count 。此外，当我点击 context menu 中的 bin 图标时，我喜欢 delete 选定的项目。

如果您看到我的代码，我认为它会有点效率。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

        }
    });

如果你能给我一些建议，我会很高兴

Answer 1

• 主活动：

      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;
      }
  
  
  }