java - 尝试使用 getChildAt() 取消选择 View

Question

我在 ExpandableListView

中使用 GridView

我有一个功能可以在点击时突出显示一个项目，现在我正在尝试实现一个按钮，当按下它时它将取消选择所有选定的项目，但它只取消选择最后一次点击的 View

public class GridAdapter extends BaseAdapter {

    private Context mContext;
    private ArrayList<Filhos> child;
    public ArrayList<CadastraEscolas> escola;
    private ArrayList<ArrayList<Filhos>> filhos = new ArrayList();



    public GridAdapter(Context context, ArrayList<CadastraEscolas> groups, ArrayList<Filhos> childValues, int groupPosition) {
        mContext = context;
        child = childValues;
        escola = groups;
        posicaoEscola = groupPosition;


    }


    @Override
    public int getCount() {
        return child.size();
    }

    @Override
    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int arg0) {
        return 0;
    }

    @Override
    public View getView(final int position, View convertView, final ViewGroup parent) {


        holder = null;



        if (convertView == null) {
            LayoutInflater inflater = (LayoutInflater) mContext
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.child_item, null);
            holder = new ViewHolder();


            final TextView idAluno = (TextView) convertView.findViewById(R.id.idcrianca);
            final TextView nomeAluno = (TextView) convertView.findViewById(R.id.name);



            convertView.setTag(holder);

            final View finalConvertView = convertView;
            convertView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {





                    if (list.size() > 0) {

                        isChecked = filhos.get(posicaoEscola).get(position).isChecked();


                        if (!isChecked) {

                            selecao(true, position, nomeAluno, 0xFFFFFFFF, finalConvertView, View.VISIBLE);


                        } else {

                            selecao(false, position, nomeAluno, 0xFFD5672B, finalConvertView, View.GONE);

                        }



                    ex.findViewById(R.id.notificar).setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(final View v) {


                            limpaSelecao(false, position, nomeAluno, 0xFFD5672B, parent, View.GONE);



                        }
                    });


                }
            });


        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.text.setText(child.get(position).getNome());


        return convertView;


    }


    static class ViewHolder {
        TextView text;
    }



   public void selecao(boolean check, int position, TextView nomeAluno, int color, View v, int visibility) {
    filhos.get(posicaoEscola).get(position).setChecked(check);
    nomeAluno.setTextColor(color);
    v.findViewById(R.id.overlay).setVisibility(visibility);
    v.findViewById(R.id.overlayText).setVisibility(visibility);
}

public void limpaSelecao(boolean check, int position, TextView nomeAluno, int color, ViewGroup v, int visibility) {



    for (int x = 0; x < group.size(); x++) {

        for (int j = 0; j < group.get(x).getalunos().size(); j++) {


            if(filhos.get(x).get(j).isChecked()){
                v.getChildAt(j).findViewById(R.id.loadingPanel).findViewById(R.id.overlay).setVisibility(View.GONE);
            }



            nomeAluno.setTextColor(color);
        }
    }


}

}

布局:

<RelativeLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:background="@drawable/nomealuno_main"
                android:layout_below="@+id/child">

                <View
                    android:id="@+id/overlay"
                    android:layout_width="125dp"
                    android:layout_height="50dp"
                    android:background="@color/bgOverlay"
                    android:visibility="gone"/>
 </RelativeLayout>

这是正在发生的事情:

当我像这样选择从 A 到 B 的所有项目时:

然后点击清除，它只会从我点击的最后一个组中删除选定的 child :

当我点击清除时，我需要将它们全部删除，所有的 child ，无论他们在哪个组中，都必须被删除。

可扩展适配器:

public class ExpandListTest extends BaseExpandableListAdapter {


    public static final int CHOICE_MODE_MULTIPLE = AbsListView.CHOICE_MODE_MULTIPLE;


    public static final int CHOICE_MODE_MULTIPLE_MODAL = AbsListView.CHOICE_MODE_MULTIPLE_MODAL;

    /**
     * No child could be selected
     */
    public static final int CHOICE_MODE_NONE = AbsListView.CHOICE_MODE_NONE;

    /**
     * One single choice per group
     */
    public static final int CHOICE_MODE_SINGLE_PER_GROUP = AbsListView.CHOICE_MODE_SINGLE;

    /**
     * One single choice for all the groups
     */
    public static final int CHOICE_MODE_SINGLE_ABSOLUTE = 10001;

    private Context context;
    public static ArrayList<CadastraEscolas> groups;
    private ArrayList<ArrayList<Filhos>> child = new ArrayList();
    private HashMap<String, GPSEscolas> aMap = new HashMap<String, GPSEscolas>();
    private HashMap<String, GPSEscolas> HashTask = new HashMap<String, GPSEscolas>();
    public static ArrayList<Filhos> listchild;
    private GridAdapter adapter;
    private SecurePreferences Sessao;
    public static CustomGridView gridView;
    private SparseArray<SparseBooleanArray> checkedPositions;
    private static final String LOG_TAG = ExpandListAdapter.class.getSimpleName();


    public ExpandListTest(Context context, ArrayList<CadastraEscolas> groups, HashMap<String, GPSEscolas> data, SecurePreferences mSessao, HashMap<String, GPSEscolas> hashTask) {
        this.context = context;
        this.groups = groups;
        this.aMap = data;
        this.Sessao = mSessao;
        checkedPositions = new SparseArray<SparseBooleanArray>();
        child = new ArrayList();
        if (groups != null) {
            for (int i = 0; i < groups.size(); i++) {
                child.add(i, groups.get(i).getalunos());
            }
        }
    }


    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return child.get(childPosition);
    }

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

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


        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) context
                    .getSystemService(context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.gridview, null);
        }


        listchild = new ArrayList<Filhos>();

        for (int j = 0; j < groups.get(groupPosition).getalunos().size(); j++) {

            listchild.add(child.get(groupPosition).get(j));

        }


        gridView = (CustomGridView) convertView.findViewById(R.id.GridView_toolbar);

        gridView.setExpanded(true);
        adapter = new GridAdapter(context, groups, listchild, child, groupPosition, aMap, HashTask, Sessao);
        gridView.setAdapter(adapter);// Adapter
        gridView.setChoiceMode(CustomGridView.CHOICE_MODE_MULTIPLE);



        return convertView;

    }


    @Override
    public int getChildrenCount(int nGroup) {
        return 1;

    }


    @Override
    public Object getGroup(int groupPosition) {
        return groups.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return groups.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        CadastraEscolas group = (CadastraEscolas) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater inf = (LayoutInflater) context
                    .getSystemService(context.LAYOUT_INFLATER_SERVICE);
            convertView = inf.inflate(R.layout.group_item, null);
        }
        ExpandableListView mExpandableListView = (ExpandableListView) parent;
        mExpandableListView.expandGroup(groupPosition);
        TextView tv = (TextView) convertView.findViewById(R.id.group_name);
        tv.setText(group.getNome_fantasia());

        return convertView;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

}

Answer 1

Android ViewGroups可以包含任意数量的Views，但是Views只能有一个父ViewGroup，如果你尝试添加一个已经有父ViewGroup的View，你会得到这个异常(来自ViewGroup.addViewInner()):

throw new IllegalStateException("The specified child already has a parent. " +
                "You must call removeView() on the child's parent first.");

这意味着您的布局结构是一棵树(而不是图)，因此您可以使用任何树遍历算法来遍历布局的每个 View 。

以下是可能的算法之一，是后序遍历。

它遍历根元素，获取第一个子元素并递归调用算法，然后是第二个、第三个等...当没有子元素要通过时，它会为节点调用取消选择函数.

对于图中的树，节点将按此顺序取消选择:

A、C、E、D、B、H、I、G、F

public void onClickTheButton(View view) {
    unselectall(R.layout.your_layout);
}

public void unselectAll(View view) {
    if(view instanceof ViewGroup) {
        for(int ii = 0 ; ii<(ViewGroup)view.getChildrenCount(); ii++) {
            unselectAll((ViewGroup)view.getChildAt(ii));
        }
    }
    unselect(view);
}

您可以在此处找到许多其他方法:https://en.wikipedia.org/wiki/Tree_traversal

如果您想简化编程体验，必须了解这些算法的工作原理。