如何将可扩展列表视图的选定子视图数据从片段发送到父活动？

Posted 2023-05-07

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【中文标题】如何将可扩展列表视图的选定子视图数据从片段发送到父活动？【英文标题】：How to send selected child view data of expandable list view from fragment to parent activity? 【发布时间】：2016-05-27 04:12:10 【问题描述】：

我有一个具有 TextView tvCount 的 ParentActivity，一个具有可扩展列表视图的片段。我需要更新在可展开列表视图中选择的子项数。

在我的片段中，我有一个适配器 -

 mExpandableListView = (ExpandableListView) view.findViewById(R.id.lvExp);
 mAdapter = new ExpandableServiceListViewAdapter(getActivity(),
            mGroups);

ExpandableServiceListViewAdapter.java

public class ExpandableServiceListViewAdapter extends BaseExpandableListAdapter 


      private static SparseArray<GroupModel> mGroups;
      public LayoutInflater mInflater;
      public Activity mActivity;



public ExpandableServiceListViewAdapter(Activity act, SparseArray<GroupModel> groups) 
    mActivity = act;
    this.mGroups = groups;
    mInflater = act.getLayoutInflater();


@Override
public Object getChild(int groupPosition, int childPosition) 
    return mGroups.get(groupPosition).children.get(childPosition);


@Override
public long getChildId(int groupPosition, int childPosition) 
    return 0;



@Override
public View getChildView(final int groupPosition, final int childPosition,
                         boolean isLastChild, View convertView, ViewGroup parent) 

    final GroupModel children = (GroupModel) getChild(groupPosition, childPosition);
    TextView title, duration, gender, actualprice, finalprice;
    final TextView tvCounter, tvTotalCost;
    ImageView offericon = null;
    final CheckBox checkBox;
    if (convertView == null) 
        convertView = mInflater.inflate(R.layout.services_item, null);
    
    title = (TextView) convertView.findViewById(R.id.tv_title);
    duration = (TextView) convertView.findViewById(R.id.tv_duration);
    gender = (TextView) convertView.findViewById(R.id.tv_gender);
    actualprice = (TextView) convertView.findViewById(R.id.tv_actualprice);
    finalprice = (TextView) convertView.findViewById(R.id.tv_finalprice);
    offericon = (ImageView) convertView.findViewById(R.id.iv_offer);
    checkBox = (CheckBox) convertView.findViewById(R.id.cb_check);
    tvTotalCost = (TextView) mActivity.findViewById(R.id.tv_cost);
    tvCounter = (TextView) mActivity.findViewById(R.id.tv_counter);

    title.setText(children.getmServiceModel().getmServiceTitle());
    duration.setText("• " + children.getmServiceModel().getmDuration() + "min");
    gender.setText("• " + children.getmServiceModel().getmGender());
    actualprice.setText("Rs " + children.getmServiceModel().getmActualPrice());
    actualprice.setPaintFlags(actualprice.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
    finalprice.setText("\u20B9" + children.getmServiceModel().getmFinalPrice());

    if (children.getmServiceModel().getmHasOffer()) 
        offericon.setVisibility(View.VISIBLE);
     else 
        offericon.setVisibility(View.INVISIBLE);
    


    convertView.setOnClickListener(new View.OnClickListener() 
        @Override
        public void onClick(View v) 

            checkBox.toggle();
            if (checkBox.isChecked()) 
                ((BaseActivity) mActivity).showToast("Yes");
                BusinessActivity.mSelectedMap.put((groupPosition * 1000) + childPosition, children);



             else 
                ((BaseActivity) mActivity).showToast("No");
                BusinessActivity.mSelectedMap.remove((groupPosition * 1000) + childPosition);

            
        
    );
    return convertView;


@Override
public int getChildrenCount(int groupPosition) 
    return mGroups.get(groupPosition).children.size();


@Override
public Object getGroup(int groupPosition) 
    return mGroups.get(groupPosition);


@Override
public int getGroupCount() 
    return mGroups.size();


@Override
public void onGroupCollapsed(int groupPosition) 
    super.onGroupCollapsed(groupPosition);


@Override
public void onGroupExpanded(int groupPosition) 
    super.onGroupExpanded(groupPosition);


@Override
public long getGroupId(int groupPosition) 
    return 0;


@Override
public View getGroupView(int groupPosition, boolean isExpanded,
                         View convertView, ViewGroup parent) 
    if (convertView == null) 
        convertView = mInflater.inflate(R.layout.services_group_header, null);
    
    GroupModel group = (GroupModel) getGroup(groupPosition);
    TextView title = (TextView) convertView.findViewById(R.id.tv_title);
    title.setText(group.getmTitle());
    TextView count = (TextView) convertView.findViewById(R.id.tv_count);
    count.setText("(" + group.getmCount() + ")");

    ImageView iv = (ImageView) convertView.findViewById(R.id.iv_offer);
    if (group.getmSubCategory().getmHasOffers())
        iv.setVisibility(View.VISIBLE);
    else
        iv.setVisibility(View.INVISIBLE);


    return convertView;


@Override
public boolean hasStableIds() 
    return false;


@Override
public boolean isChildSelectable(int groupPosition, int childPosition) 
    return false;

在这里，我正在尝试创建所选子项的地图，我需要将其发送到父活动以更新计数。

BusinessActivity.java 是具有片段的父活动。我在活动中定义了 mSelectedMap。我在选择时将条目添加到此地图中，在未选择时将其删除。

有人可以帮我如何设置此适配器的父活动中的计数值。

【问题讨论】：

您想将整个BusinessActivity.mSelectedMap 发送到父活动吗？如果是的话，你在哪里创建那个对象？ mSelectedMap 到底是什么？ 【参考方案1】：

有 3 种方法可以解决您的问题。

使用全局静态变量，在您的片段中定义其值并在您的活动中显示其值。在您的活动中创建方法并使用适当的参数从片段中调用它。使用EventBus。

EventBus 简化了组件之间的通信。它在活动、片段和后台线程中表现良好。

Here 是 EventBus 的一个很好的例子。

【讨论】：

嗨，这是推荐的这种交流方式。 EventBus 看起来简单又好用。下面的答案使用接口进行通信。您认为最好的方法是什么？我更喜欢 EventBus【参考方案2】：

试试这个...

ExpandableServiceListViewAdapter.java

public class ExpandableServiceListViewAdapter extends BaseExpandableListAdapter 


private SparseArray<GroupModel> mGroups;
public LayoutInflater mInflater;
public Activity mActivity;
private OnChildClick onChildClick;


public ExpandableServiceListViewAdapter(Activity act, SparseArray<GroupModel> groups,
                                        OnChildClick onChildClick) 
    mActivity = act;
    this.mGroups = groups;
    this.onChildClick = onChildClick;
    mInflater = act.getLayoutInflater();
    


@Override
public View getChildView(final int groupPosition, final int childPosition,
                         boolean isLastChild, View convertView, ViewGroup parent) 

    final GroupModel children = (GroupModel) getChild(groupPosition, childPosition);
    ........

    convertView.setOnClickListener(new View.OnClickListener() 
        @Override
        public void onClick(View v) 

            checkBox.toggle();
            if (checkBox.isChecked()) 
                if (null != onChildClick) 
                    onChildClick.onClick((groupPosition * 1000) + childPosition, children, "Yes");
                
             else 
                if (null != onChildClick) 
                    onChildClick.onClick((groupPosition * 1000) + childPosition, children, "No");
                
            
        
    );
    return convertView;
  



  //other override methods
  ......

   //interface to get selected item
   public interface OnChildClick 
     void onClick(int position, GroupModel children, String status);

YourFragment.java

public class YourFragment extends Fragment

   private OnItemSelectedListener mCallback;
   private Activity activity;
   ExpandableServiceListViewAdapter mAdapter;
   ExpandableListView mExpandableListView;
   .....

   @Override
   public void onAttach(Activity activity) 
    super.onAttach(activity);

    // This makes sure that the container activity has implemented
    // the callback interface. If not, it throws an exception
    try 
        mCallback = (OnItemSelectedListener) activity;
     catch (ClassCastException e) 
        throw new ClassCastException(activity.toString()
                + " must implement OnItemSelectedListener");
    
   


   // interface to update UI changes in BusinessActivity at runtime
   public interface OnItemSelectedListener 
     void onItemPicked(int position,GroupModel children, String status);
   
 
   @Override
   public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 

    View view = inflater.inflate(R.layout.fragment_expandable_list, container, false);
    mExpandableListView = (ExpandableListView) view.findViewById(R.id.lvExp);
    return view;
    

   @Override
   public void onActivityCreated(Bundle savedInstanceState)
    super.onActivityCreated(savedInstanceState);

      mAdapter = new ExpandableServiceListViewAdapter(getActivity(),
            mGroup, mOnChildClick);

   

       private ExpandableServiceListViewAdapter.OnChildClick mOnChildClick
        = new ExpandableServiceListViewAdapter.OnChildClick() 
    @Override
    public void onClick(int position,GroupModel children, String status) 

       // Through interface
        try 
            ((OnItemSelectedListener) activity).onItemPicked(position, children, status);
         catch (Exception cce) 
            cce.printStackTrace();
        


        //OR accsee directly

        if(status.equalsIgnoreCase("Yes"))
            ((BusinessActivity)activity).mSelectedMap.put(position, children);
        else 
            ((BusinessActivity)activity).mSelectedMap.remove(position);
        
      
    ;

BusinessActivity.java

 public class BusinessActivity extends Activity implements YourFragment.OnItemSelectedListener
  
  .....

  //Override the method here
  @Override
  public void onItemPicked(position, children, status)
  
    //Do something with the position value passed back
    Toast.makeText(activity, "status "+ status, Toast.LENGTH_LONG).show();
     //Do something with the position value passed back
    Toast.makeText(activity, "status "+ status, Toast.LENGTH_LONG).show();
    if(status.equalsIgnoreCase("Yes"))
           mSelectedMap.put(position, children) 
    else 
           mSelectedMap.remove(position);
    
   
 
  .....

【讨论】：

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