使用带有片段的上下文操作栏

Question

我目前正在研究android项目并使用片段和ListViews/ListFragments.我有上下文操作栏来处理标准活动,例如ListActivity.

现在我尝试做同样的事情,但在片段布局上.我有一个MainActivity,它扩展了Activity,它为包含2个片段,片段A和片段B的布局扩展了XML.

片段A扩展了ListFragment并包含一个ListView,它从SQLite数据库中的数据填充.当我有一个上下文操作栏上的标准ListActivity工作,我有一个扩展ListView.MultiChoiceModeListener但是这不适用于一个ListFragment类或标准的活动,这样我将如何去实现这个类.

我想要实现的基本功能是当有人长时间在FragmentA中的ListView中按下项目时,它会扩展ListFragment,操作栏会在上下文中更改,然后用户可以从ListView中选择多个项目.

感谢您的任何帮助,您可以提供.

Answer 1

当我有一个上下文操作栏上的标准ListActivity工作,我有一个扩展ListView.MultiChoiceModeListener但是这不适用于一个ListFragment类或标准的活动,这样我将如何去实现这个类.

我不知道怎么MultiChoiceModeListener没有(也许我不明白你试图做什么).从您的评论我假设您使用兼容包中的片段.下面是一个FragmentActivity包含两个静态片段的示例,每个片段都会触发上下文操作栏及其自己的菜单选项.

这FragmentActivity很简单,它只包含以下两个片段:

// the list fragment
public class ListCABFragment extends ListFragment {

    private String[] mCountries = { "Romania", "Germany", "England", "USA",
            "Japan", "France" };
    private static final boolean POST_HONEYCOMB = Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        if (POST_HONEYCOMB) {
            // make sure we are on a version above Honeycomb otherwise will
            // access things that aren't available
            postHoneycombCAB();
        } else {
            // probably do nothing and implement the normal context menu?!?
        }
        setListAdapter(new ArrayAdapter<String>(getActivity(),
                android.R.layout.simple_list_item_1, mCountries));
    }

    @SuppressLint({ "NewApi", "NewApi" })
    private void postHoneycombCAB() {
        getListView().setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
        getListView().setOnItemLongClickListener(new OnItemLongClickListener() {

            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view,
                    int position, long id) {
                ((ListView) parent).setItemChecked(position,
                        ((ListView) parent).isItemChecked(position));
                return false;
            }
        });
        getListView().setMultiChoiceModeListener(new MultiChoiceModeListener() {

            private int nr = 0;

            @Override
            public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                getActivity().getMenuInflater().inflate(R.menu.listcab_menu,
                        menu);
                return true;
            }

            @Override
            public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
                return false;
            }

            @Override
            public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
                switch (item.getItemId()) {
                case R.id.item1:
                    Toast.makeText(getActivity(), "Option1 clicked",
                            Toast.LENGTH_SHORT).show();
                    break;
                case R.id.item2:
                    Toast.makeText(getActivity(), "Option2 clicked",
                            Toast.LENGTH_SHORT).show();
                    break;

                }
                return false;
            }

            @Override
            public void onDestroyActionMode(ActionMode mode) {
                nr = 0;
            }

            @Override
            public void onItemCheckedStateChanged(ActionMode mode,
                    int position, long id, boolean checked) {
                if (checked) {
                    nr++;
                } else {
                    nr--;
                }
                mode.setTitle(nr + " rows selected!");
            }
        });
    }
}

另一个片段Fragment的布局由a组成,RadioGroup当RadioButton选择a时触发CAB :

public class SimpleCABFragment extends Fragment implements Callback {

    private static final boolean POST_HONEYCOMB = Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        return inflater.inflate(R.layout.frag_simplecabfragment, container,
                false);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        RadioGroup rg = (RadioGroup) getView().findViewById(R.id.radioGroup1);
        rg.setOnCheckedChangeListener(new OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                if (POST_HONEYCOMB) {
                    // this could be improved so we don't need to create the
                    // option
                    // menu if it is already available
                    getActivity().startActionMode(SimpleCABFragment.this);
                } else {
                    // something else
                }
            }
        });
    }

    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
        if (item.getItemId() == R.id.itemradio) {
            Toast.makeText(getActivity(), "CAB for Radiogroup!",
                    Toast.LENGTH_SHORT).show();
        }
        return false;
    }

    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
        getActivity().getMenuInflater().inflate(R.menu.simplecab_menu, menu);
        return true;
    }

    @Override
    public void onDestroyActionMode(ActionMode mode) {
    }

    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
        return false;
    }
}

看看这是否是您正在寻找的(您可以在我的github项目中找到包括布局和菜单文件的完整示例).