从 Fragments ListView 中的 CheckBox 启用上下文菜单

Question

我有一个 Fragment，其中嵌入了一个 ListView 和其他一些 View。 ListView 正在为其列表项使用自定义布局，请参见下文。

编辑：这是我想要实现的。来自文档：

In some cases in which the contextual actions provide common action items, you might want to add a checkbox or a similar UI element that allows users to select items, because they might not discover the long-click behavior. When a user selects the checkbox, you can invoke the contextual action mode by setting the respective list item to the checked state with setItemChecked().

CustomListViewItem.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_margin="@dimen/activity_vertical_margin"
    android:layout_width="match_parent"
    android:weightSum="10"
    android:layout_height="wrap_content">

    <LinearLayout
        android:layout_weight="1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:textStyle="bold"
            android:layout_width="wrap_content"
            android:ellipsize="end"
            android:singleLine="true"
            android:layout_height="wrap_content"
            android:text="New Text"
            android:id="@+id/tvNotesListAdapterTitle" />

        <TextView
            android:textStyle="italic"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="New Text"
            android:id="@+id/tvNotesListAdapterTimestamp" />
    </LinearLayout>

    <RelativeLayout

        android:layout_weight="9"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">

        <CheckBox
            android:id="@+id/cb_notes"
            android:button="@null"
            android:drawableRight="?android:attr/listChoiceIndicatorMultiple"
            android:drawableEnd="?android:attr/listChoiceIndicatorMultiple"
            android:layout_centerVertical="true"
            android:focusable="false"
            android:focusableInTouchMode="false"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" />
    </RelativeLayout>


</LinearLayout>

CheckBox 的目的是让用户能够调用 Contextual Menu。但是，我似乎没有做对。正如开发人员示例所示，我在长按 ListView 项时成功调用了上下文菜单。这是在托管 ListView.

的 Fragment 中完成的

如何以及在何处对 ListView 中的 CheckBox 执行相同的操作？在 ArrayAdapter 或 Fragment?

下面是自定义代码 ArrayAdapter。

CustomArrayAdapter.java:

public class NotesArrayAdapter extends ArrayAdapter<Note> {

    private ArrayList<Note> allNotes;

    public NotesArrayAdapter(Context ctx, ArrayList<Note> allNotes) {
        super(ctx, R.layout.arrayadapter_notes, allNotes);
        this.allNotes = allNotes;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row;
        if (convertView == null) {
            LayoutInflater inflater = LayoutInflater.from(getContext());
            //R.layout.arrayadapter_notes is my custom layout for my ListView items.
            row = inflater.inflate(
                    R.layout.arrayadapter_notes, null);
        } else {
            row = convertView;
        }

        TextView tvTitle = (TextView) row.findViewById(R.id.tvNotesListAdapterTitle);
        TextView tvTimeStamp = (TextView) row.findViewById(R.id.tvNotesListAdapterTimestamp);

        String timeStamp = allNotes.get(position).getTimestamp();
        String note = allNotes.get(position).getNote();

        tvTitle.setText(note);
        tvTimeStamp.setText(timeStamp);

        return row;
    }

}

我还没有找到上述内容的任何工作示例。在这件事上的任何帮助将不胜感激。简而言之，当一个或多个 CheckBox 被选中时，我不确定在哪里以及如何调用上下文菜单。

Answer 1

通过在我的 ArrayAdapter class 中实现回调接口解决了这个问题

private NotesAdapterCallback callback;

public interface NotesAdapterCallback {
    public void checkBoxChecked();
}

public void setCallback(NotesAdapterCallback callback) {
    this.callback = callback;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row;
    if (convertView == null) {
        LayoutInflater inflater = LayoutInflater.from(getContext());
        row = inflater.inflate(
                R.layout.arrayadapter_notes, null);
    } else {
        row = convertView;
    }

    TextView tvTitle = (TextView) row.findViewById(R.id.tvNotesListAdapterTitle);
    TextView tvTimeStamp = (TextView) row.findViewById(R.id.tvNotesListAdapterTimestamp);
    CheckBox cbNote = (CheckBox) row.findViewById(R.id.cb_notes);

    String timeStamp = allNotes.get(position).getTimestamp();
    String note = allNotes.get(position).getNote();

    tvTitle.setText(note);
    tvTimeStamp.setText(timeStamp);

    cbNote.setOnCheckedChangeListener(this);

    return row;

}

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    if (isChecked) {
        if (callback != null) {
            callback.checkBoxChecked();
        }
    }
}

并像这样在我的 Fragment 中实现接口

private ActionMode mActionMode;

@Override
public void checkBoxChecked() {
    if (mActionMode != null) {
        return;
    }else{
        mActionMode = getActivity().startActionMode(mActionModeCallback);
    }
}

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);
        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.context_delete:

                mode.finish(); // Action picked, so close the CAB
                return true;
            case R.id.context_move:

                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;
    }
};

不要忘记在 ArrayAdapter

上设置回调

notesAdapter = new NotesArrayAdapter(getActivity(), allNotes);
lwNotes.setAdapter(notesAdapter);
notesAdapter.setCallback(this);

从 Fragments ListView 中的 CheckBox 启用上下文菜单

Enable the context menu from a CheckBox in a Fragments ListView

android

android-listview

android-fragments