从 PauseHandler 实现调用 SupportFragmentManager

Question

我正在尝试实现此处描述的 PauseHandler：

https://stackoverflow.com/a/8122789/1977132

我的活动是一个ActionBarActivity，processMessage方法中的代码会弹出一个对话框给出错误Cannot resolve method 'getSupportFragmentManager'

按照这里的建议： https://stackoverflow.com/a/27425568/1977132

我尝试将其更改为 getFragmentManager() 但随后出现错误 Cannot resolve method 'show(android.app.FragmentManager(), java.lang.String'

我在此处粘贴了我认为是相关代码的内容：

import android.support.v4.app.DialogFragment;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;

public class PlaySession extends ActionBarActivity implements View.OnClickListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (savedInstanceState == null) {
            final Fragment state = new State();
            final FragmentManager fm = getSupportFragmentManager();
            final FragmentTransaction ft = fm.beginTransaction();
            ft.add(state, State.TAG);
            ft.commit();
        }
    }

    public static class rescanDialogBox extends DialogFragment {
        final static String TAG = "RESCAN";

        public static rescanDialogBox newInstance(int title) {
            rescanDialogBox frag = new rescanDialogBox();
            Bundle args = new Bundle();
            args.putInt("title", title);
            frag.setArguments(args);
            return frag;
        }

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            String title = "Rescan?";
            String message = "No Bluetooth LE devices found. Do you want to rescan? If you keep getting this message check the battery of your Bluetooth device.";

            AlertDialog.Builder myDialogBuilder = new AlertDialog.Builder(getActivity());
            myDialogBuilder.setTitle(title);
            myDialogBuilder.setMessage(message);
            myDialogBuilder.setPositiveButton("YES",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        ((PlaySession) getActivity()).yesRescan();
                    }
                });
            myDialogBuilder.setNegativeButton("NO",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        ((PlaySession) getActivity()).noRescan();
                    }
                });

            AlertDialog myDialog = myDialogBuilder.create();
            myDialog.setCanceledOnTouchOutside(false);

            return myDialog;
        }
    }

    public void yesRescan() {
        //rescan
    }

    public void noRescan() {
        //do nothing
    }

    final static class State extends Fragment {
        static final String TAG = "State";
        public PauseHandlerImplementation handler = new PauseHandlerImplementation();

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setRetainInstance(true);
        }

        @Override
        public void onResume() {
            super.onResume();
            handler.setActivity(getActivity());
            handler.resume();
        }

        @Override
        public void onPause() {
            super.onPause();
            handler.pause();
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            handler.setActivity(null);
        }
    }


    static class PauseHandlerImplementation extends PauseHandler {
        protected Activity activity;

        final void setActivity(Activity activity) {
            this.activity = activity;
        }

        @Override
        final protected void processMessage(String toDo) {
            final Activity activity = this.activity;

            if (activity != null) {
                if(toDo.equals("OFFER_RESCAN")) {
                    //offer rescan
                    DialogFragment newFragment = new rescanDialogBox();
                    newFragment.show(activity.getSupportFragmentManager(), rescanDialogBox.TAG);
                    activity.getSupportFragmentManager().executePendingTransactions();

                } else if (toDo.equals("OFFER_DEVICES")) {
                    //offer devices
                }
            }
        }
    }
}

当然，还有用于扩展 Handler 的 PauseHandler 的代码和用于对话框的代码，但它们工作正常，因此似乎不相关。

编辑 添加了重新扫描对话框的代码，此对话框在我添加 PauseHandler 之前运行良好，但我需要添加对用户在扫描过程中离开应用程序的情况的支持，因此需要 PauseHandler

Answer 1

首先，ActionBarActivity现在已弃用。您可能应该使用AppCompatActivity 来支持以前的Android 版本。

其次，您应该使用.replace(int ontainerViewId, Fragment fragment) 方法指定放置State 片段的容器。您的方法应如下所示：

final Fragment state = new State();
final FragmentManager fm = getSupportFragmentManager();
final FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.your_container_id, state);
ft.commit();

希望对你有帮助！

Answer 2

我遇到了和你一样的问题，我觉得你应该改一下

import android.support.v4.app.DialogFragment

到

import android.app.DialogFragment;

在您的DialogFragment 班级中