列表视图项的Android工具栏上下文菜单

Question

我正在寻找有关如何在ListView项目的工具栏中实现上下文菜单的帮助,如WhatsApp所做的那样.到目前为止我发现的唯一教程是关于弹出的对话框,这不是我想要的.有人可以帮助我或提供教程链接吗？谢谢 :)

Answer 1

检查这个官方的android指南.

编辑:

使用上下文操作模式

对于提供上下文操作的视图,通常应该在两个事件(或两者)之一上调用上下文操作模式:

• 用户在视图上执行长按.
• 用户在视图中选择复选框或类似的UI组件.

应用程序如何调用上下文操作模式并定义每个操作的行为取决于您的设计.基本上有两种设计:

• 对于单个任意视图的上下文操作.
• 对于ListView或GridView中的项目组的批处理上下文操作(允许用户选择多个项目并对它们执行所有操作).

为各个视图启用上下文操作模式

1. 实现ActionMode.Callback接口.在其回调方法中,您可以指定上下文操作栏的操作,响应操作项上的单击事件以及处理操作模式的其他生命周期事件.

   private ActionMode.Callback mActionModeCallback = new             ActionMode.Callback() {
   
   // Called when the action mode is created; startActionMode() was called
   @Override
   public boolean onCreateActionMode(ActionMode mode, Menu menu) {
       // Inflate a menu resource providing context menu items
       MenuInflater inflater = mode.getMenuInflater();
       inflater.inflate(R.menu.context_menu, menu);
       return true;
   }
   
   // Called each time the action mode is shown. Always called after onCreateActionMode, but
   // may be called multiple times if the mode is invalidated.
   @Override
   public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
       return false; // Return false if nothing is done
   }
   
   // Called when the user selects a contextual menu item
   @Override
   public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
       switch (item.getItemId()) {
           case R.id.menu_share:
               shareCurrentItem();
               mode.finish(); // Action picked, so close the CAB
               return true;
           default:
               return false;
       }
   }
   
   // Called when the user exits the action mode
   @Override
   public void onDestroyActionMode(ActionMode mode) {
       mActionMode = null;
   }
   };
   

2. 要显示栏时调用startActionMode()(例如,当用户长按视图时).

   someView.setOnLongClickListener(new View.OnLongClickListener() {
   // Called when the user long-clicks on someView
   public boolean onLongClick(View view) {
       if (mActionMode != null) {
           return false;
       }
   
       // Start the CAB using the ActionMode.Callback defined above
       mActionMode = getActivity().startActionMode(mActionModeCallback);
       view.setSelected(true);
       return true;
   }
   });
   

在ListView或GridView中启用批处理上下文操作

如果ListView或GridView(或AbsListView的另一个扩展)中有一组项目,并且希望允许用户执行批处理操作,则应该:

• 实现AbsListView.MultiChoiceModeListener接口,并使用setMultiChoiceModeListener()为视图组设置它.在侦听器的回调方法中,您可以指定上下文操作栏的操作,响应操作项上的单击事件,以及处理从ActionMode.Callback接口继承的其他回调.

• 使用CHOICE_MODE_MULTIPLE_MODAL参数调用setChoiceMode().

  ListView listView = getListView();
  listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
  listView.setMultiChoiceModeListener(new MultiChoiceModeListener() {
  
  @Override
  public void onItemCheckedStateChanged(ActionMode mode, int position,
                                        long id, boolean checked) {
      // Here you can do something when items are selected/de-selected,
      // such as update the title in the CAB
  }
  
  @Override
  public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
      // Respond to clicks on the actions in the CAB
      switch (item.getItemId()) {
          case R.id.menu_delete:
              deleteSelectedItems();
              mode.finish(); // Action picked, so close the CAB
              return true;
          default:
              return false;
      }
  }
  
  @Override
  public boolean onCreateActionMode(ActionMode mode, Menu menu) {
      // Inflate the menu for the CAB
      MenuInflater inflater = mode.getMenuInflater();
      inflater.inflate(R.menu.context, menu);
      return true;
  }
  
  @Override
  public void onDestroyActionMode(ActionMode mode) {
      // Here you can make any necessary updates to the activity when
      // the CAB is removed. By default, selected items are deselected/unchecked.
  }
  
  @Override
  public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
      // Here you can perform updates to the CAB due to
      // an invalidate() request
      return false;
  }
  });
  

有关更多菜单功能,请查看此链接.