2

我有 3 个 ArrayList> 我想传递给 3 个片段。除了使它们静态之外，最好的方法是什么？

4

2 回答 2

3

您可以在片段中使用 setArguments。看看http://developer.android.com/guide/components/fragments.html，基本上，您在创建 Fragment 之前创建一个 Bundle，然后将其设置为 Argument。

Android 文档中的示例：

public static class DetailsActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (getResources().getConfiguration().orientation
                == Configuration.ORIENTATION_LANDSCAPE) {
            // If the screen is now in landscape mode, we can show the
            // dialog in-line with the list so we don't need this activity.
            finish();
            return;
        }

        if (savedInstanceState == null) {
            // During initial setup, plug in the details fragment.
            DetailsFragment details = new DetailsFragment();
            details.setArguments(getIntent().getExtras());
            getFragmentManager().beginTransaction().add(android.R.id.content, details).commit();
        }
    }
}

您可以创建捆绑包并设置参数，而不是使用 getIntent().getExtras()

Bundle bundle = new Bundle();
bundle.putSerializable(YOUR_KEY, yourObject);
fragment.setArguments(bundle);

对于你的片段：

public static class DetailsFragment extends Fragment {
    /**
     * Create a new instance of DetailsFragment, initialized to
     * show the text at 'index'.
     */
    public static DetailsFragment newInstance(int index) {
        DetailsFragment f = new DetailsFragment();

        // Supply index input as an argument.
        Bundle args = new Bundle();
        args.putInt("index", index);
        f.setArguments(args);

        return f;
    }

    public int getShownIndex() {
        return getArguments().getInt("index", 0);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        if (container == null) {
            // We have different layouts, and in one of them this
            // fragment's containing frame doesn't exist.  The fragment
            // may still be created from its saved state, but there is
            // no reason to try to create its view hierarchy because it
            // won't be displayed.  Note this is not needed -- we could
            // just run the code below, where we would create and return
            // the view hierarchy; it would just never be used.
            return null;
        }

        ScrollView scroller = new ScrollView(getActivity());
        TextView text = new TextView(getActivity());
        int padding = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
                4, getActivity().getResources().getDisplayMetrics());
        text.setPadding(padding, padding, padding, padding);
        scroller.addView(text);
        text.setText(Shakespeare.DIALOGUE[getShownIndex()]);
        return scroller;
    }
}
于 2012-08-09T14:04:20.393 回答
1

您可以创建侦听器回调接口并在您的片段中实现它们。像这样的东西：

@Override
public void onSomeEvent(List<SomeData> data) {
    //do something with data
}

在您的活动中创建此界面：

public interface OnSomeEventListener {
    onSomeEvent(List<SomeData> data);
}

然后使用 findFragmentById 或 findFragmentByTag 获取您的片段并将其分配给侦听器：

this.onSomeEventListener = fragment;

然后您可以调用该接口的方法，您的片段将接收回调。

片段和活动之间的第二种更简单的通信方式是广播接收器。您可以在片段中注册一些广播接收器，然后从活动中调用 sendBroadcast()。您的数据列表可以放在该广播消息的捆绑中。

于 2012-08-09T14:22:38.397 回答