java - 获取用于 FragmentTransaction 的 containerViewId

Question

我正在尝试让两个 Fragment 通过 Activity 中的接口(interface)相互通信。当在带有 ListView 的 Fragment 中单击一行时，它会向 Activity 发送一个 ID，然后需要将其传递并调用另一个 Fragment 中的方法。 fragment 是 ViewPager 的一部分，因为它们是可交换的选项卡。

当前创建第二个 Fragment 会导致应用程序崩溃，因为我试图将其放入布局中，而不是我认为的容器中。

所以，我需要获取 WebViewFragment 的 Container，这样我就可以使用 FragmentTransaction 并将其放入容器中 - 是这样吗正确的？如果是这样，我如何获得容器？

MyPagerAdapter:

public class TabsPagerAdapter extends FragmentPagerAdapter {
    public TabsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        switch(position) {
            case 0:
                return new SfnViewerFragment();
            case 1:
                return new DirectoryFragment();
            case 2:
                return new HelpFragment();
        }

        return null;
    }

    @Override
    public int getCount() {
        return 3;
    }

}

ListViewFragment:

public class DirectoryFragment extends Fragment {
    SimpleCursorAdapter adapter;
    Cursor cursor;
    OnViewerSelectedListener mCallback;

    // Interface to send Id of viewer to activity, which is then passed
    // To the fragment containing the WebView
    public interface OnViewerSelectedListener {
        public void onViewerSelected(Long id);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        // Make sure the container activity has implemented the interface.
        // If it hasn't throw and exception.
        try {
            mCallback = (OnViewerSelectedListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
            + " must implement OnViewerSelectedListener");
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_directory, container, false);

        ListView listView = (ListView) rootView.findViewById(R.id.list);

        DatabaseHelper dbHelper = new DatabaseHelper(getActivity());

        // Use a cursor adapter to tie database info with the ListView
        final SimpleCursorAdapter adapter = new SimpleCursorAdapter(getActivity(), android.R.layout.simple_list_item_1, dbHelper.getViewers(), new String[] { "description", "_id" }, new int[] { android.R.id.text1 }, CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
        listView.setAdapter(adapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Long id = adapter.getItemId(i);

                mCallback.onViewerSelected(id);
            }
        });

        return rootView;
    }

}

主要 Activity :

public class MainActivity extends FragmentActivity implements ActionBar.TabListener, DirectoryFragment.OnViewerSelectedListener {

    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private ActionBar actionBar;

    //Tab Titles
    private String[] tabs = { "sfn Viewer", "Directory", "Help" };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        DatabaseHelper db = new DatabaseHelper(this);

        //Initialization
        viewPager = (ViewPager) findViewById(R.id.pager);
        actionBar = getActionBar();
        mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

        viewPager.setAdapter(mAdapter);
        actionBar.setHomeButtonEnabled(false);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        //Adding Tabs
        for (String tab_name : tabs) {
            actionBar.addTab(actionBar.newTab().setText(tab_name).setTabListener(this));
        }

        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                //On changing page, make sure right tab is selected
                actionBar.setSelectedNavigationItem(position);
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {}

            @Override
            public void onPageScrollStateChanged(int arg0) {}
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            Toast.makeText(this, "Settings selected", Toast.LENGTH_SHORT).show();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onViewerSelected(Long id) {
        SfnViewerFragment sfnViewerFragment = (SfnViewerFragment)
                getSupportFragmentManager().findFragmentByTag("android:switcher:" + R.id.pager + ":0");

        sfnViewerFragment.getWebView(id);

        //viewPager.setCurrentItem(0, true);
    }

    @Override
    public void onTabSelected(ActionBar.Tab tab, android.app.FragmentTransaction fragmentTransaction) {
        //When the tab is selected show the correct fragment
        viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, android.app.FragmentTransaction fragmentTransaction) {

    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, android.app.FragmentTransaction fragmentTransaction) {

    }
}

WebViewFragment:

public class SfnViewerFragment extends Fragment {
    private WebView webView;
    private View rootView;
    private HashMap<Long, WebView> webViews;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        rootView = inflater.inflate(R.layout.fragment_sfn_viewer, container, false);

        return rootView;
    }
    public void getWebView(Long id) {
        if (!webViews.containsKey(id)) {
            createWebView(id);
            webView = webViews.get(id);
            webView.setVisibility(View.VISIBLE);
            FrameLayout mWebContainer = (FrameLayout) getView().findViewById(R.id.web_container);
            mWebContainer.addView(webView);
        } else {
            webView = webViews.get(id);
            webView.setVisibility(View.VISIBLE);
            FrameLayout mWebContainer = (FrameLayout) getView().findViewById(R.id.web_container);
            mWebContainer.addView(webView);
        }
    }

    public void createWebView(Long id) {
        WebView wv = new WebView(getActivity());
        wv.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageFinished(WebView view, String url) {
                view.loadUrl("javascript:(registerCredentialsChangedCallback(function(credentials) {if (credentials.length >= 1) {window.location.href = 'callback:' + credentials;} else {alert('Error: callback set by registerCredentialsChangedCallback was given null string');}})) ()");
            }
        });
        WebSettings webSettings = wv.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setUseWideViewPort(true);
        webSettings.setLoadWithOverviewMode(true);

        wv.loadUrl(makeViewerURL(id));

        webViews.put(id, wv);

        Log.d("createWebView: ", "WebView Created.");
    }

    public String makeViewerURL(Long id) {

        DatabaseHelper dbHelper = new DatabaseHelper(getActivity());
        Viewer clickedViewer = dbHelper.getViewer(id);

        String url = clickedViewer.getHostURL() + "/" + clickedViewer.getWebApp() + "/viewer?username=" +
                clickedViewer.getUsername() + "&pw=" + clickedViewer.getPassword() + "&modelId=" + clickedViewer.getModelId() + "&" + clickedViewer.getProperties();

        Log.d("Url is: ", url);

        return url;
    }
}

运行应用程序时出错:

java.lang.IllegalArgumentException: No view found for id 0x7f03001b (com.lightfootsolutions.sfnviewer.app:layout/fragment_sfn_viewer) for fragment SfnViewerFragment{b1f8d2e8 #3 id=0x7f03001b}
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:930)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1115)
        at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
        at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1478)
        at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:478)
        at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1068)
        at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:550)
        at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:509)
        at android.support.v4.view.ViewPager.setCurrentItem(ViewPager.java:501)
        at com.lightfootsolutions.sfnviewer.app.MainActivity.onViewerSelected(MainActivity.java:120)
        at com.lightfootsolutions.sfnviewer.app.DirectoryFragment$1.onItemClick(DirectoryFragment.java:79)
        at android.widget.AdapterView.performItemClick(AdapterView.java:299)
        at android.widget.AbsListView.performItemClick(AbsListView.java:1113)
        at android.widget.AbsListView$PerformClick.run(AbsListView.java:2904)
        at android.widget.AbsListView$3.run(AbsListView.java:3638)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5017)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
        at dalvik.system.NativeStart.main(Native Method)

当我点击一行时，它会崩溃。

Answer 1

要使用新数据更新其他 fragment ，您不应执行新事务，因为该 fragment 位于 ViewPager 中。相反，获取对寻呼机 fragment 的引用并调用其更新方法并向其传递 id:

@Override
public void onViewerSelected(Long id) {
     SfnViewerFragment sfnViewerFragment = (SfnViewerFragment)
     getSupportFragmentManager().findFragmentByTag("android:switcher:" + R.id.pager + ":0"); 
     sfnViewerFragment.getWebView(id);
}