＆＃34;不幸的是，App停止了＃34;单击ListView中的Item to Fragment Activity

Question

我是这个应用程序的初学者，在将Listview放入Tab Activity后我遇到了这个问题。在Listview中有一些项目可以用于VR全景视图的新活动（该活动是碎片）我将显示代码和logcat。

ImageLoaderTask

package com.example.computer.vratdragfinal;

import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.os.AsyncTask;

import com.google.vr.sdk.widgets.pano.VrPanoramaView;
import java.lang.ref.WeakReference;

import android.graphics.BitmapFactory;
import android.util.Log;

import java.io.IOException;
import java.io.InputStream;

public class ImageLoaderTask extends AsyncTask<AssetManager, Void, Bitmap> {

    private static final String TAG = "ImageLoaderTask";
    private final String assetName;
    private final WeakReference<VrPanoramaView> viewReference;
    private final VrPanoramaView.Options viewOptions;

    private static WeakReference<Bitmap> lastBitmap = new WeakReference<>(null);
    private static String lastName;

    @Override
    protected Bitmap doInBackground(AssetManager... params) {
        AssetManager assetManager = params[0];

        if (assetName.equals(lastName) && lastBitmap.get() != null) {
            return lastBitmap.get();
        }

        try(InputStream istr = assetManager.open(assetName)) {
            Bitmap b = BitmapFactory.decodeStream(istr);
            lastBitmap = new WeakReference<>(b);
            lastName = assetName;
            return b;
        } catch (IOException e) {
            Log.e(TAG, "Could not decode default bitmap: " + e);
            return null;
        }
    }

    @Override
    protected void onPostExecute(Bitmap bitmap) {
        final VrPanoramaView vw = viewReference.get();
        if (vw != null && bitmap != null) {
            vw.loadImageFromBitmap(bitmap, viewOptions);
        }
    }

    public ImageLoaderTask(VrPanoramaView view, VrPanoramaView.Options viewOptions, String assetName) {
        viewReference = new WeakReference<>(view);
        this.viewOptions = viewOptions;
        this.assetName = assetName;
    }

}

MainActivity

package com.example.computer.vratdragfinal;

import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
        assert tabLayout != null;
        tabLayout.addTab(tabLayout.newTab().setText(R.string.welcome));
        tabLayout.addTab(tabLayout.newTab().setText(R.string.venue));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

        final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
        final PagerAdapter adapter = new FragmentStatePagerAdapter(getSupportFragmentManager()) {

            @Override
            public Fragment getItem(int position) {
                switch (position) {
                    case 0:
                        return new WelcomeFragment();
                    case 1:
                        return new ttsd();
                }
                return null;
            }

            @Override
            public int getCount() {
                return 2;
            }
        };
        assert viewPager != null;
        viewPager.setAdapter(adapter);
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });
    }

    public void refreshNow() {
        finish();
        overridePendingTransition(0,0);
        startActivity(getIntent());
        overridePendingTransition(0,0);

    }

}

toptourist1

package com.example.computer.vratdragfinal;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.google.vr.sdk.widgets.pano.VrPanoramaView;

public class toptourist1 extends Fragment {

    private VrPanoramaView panoWidgetView;
    private ImageLoaderTask backgroundImageLoaderTask;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v =  inflater.inflate(R.layout.activity_toptourist1, container,false);
        panoWidgetView = (VrPanoramaView) v.findViewById(R.id.pano_view);
        return v;
    }

    @Override
    public void onPause() {
        panoWidgetView.pauseRendering();
        super.onPause();
    }

    @Override
    public void onResume() {
        panoWidgetView.resumeRendering();
        super.onResume();
    }

    @Override
    public void onDestroy() {

        panoWidgetView.shutdown();
        super.onDestroy();
    }

    private synchronized void loadPanoImage() {
        ImageLoaderTask task = backgroundImageLoaderTask;
        if (task != null && !task.isCancelled()) {
            task.cancel(true);
        }

        VrPanoramaView.Options viewOptions = new VrPanoramaView.Options();
        viewOptions.inputType = VrPanoramaView.Options.TYPE_STEREO_OVER_UNDER;

        String panoImageName = "sample_converted.jpg";

        task = new ImageLoaderTask(panoWidgetView, viewOptions, panoImageName);
        task.execute(getActivity().getAssets());
        backgroundImageLoaderTask = task;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        loadPanoImage();
    }

}

TTSD

package com.example.computer.vratdragfinal;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.content.Intent;
import android.widget.AdapterView;

public class ttsd extends Fragment {


    public ttsd() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.ttsd, container, false);
        // Inflate the layout for this fragment
        String[] awayStrings = {
                "Tubbataha Reef",
                "San Agustin Church",
                "Mayon Volcano",
                "Malapascua Island",
                "Puerto Galera",
                "Puerto Princesa Undergound River",
                "Donsol",
                "Banaue Rice Terraces",

        };

        ListView lv = (ListView) view.findViewById(R.id.listView2);

        ArrayAdapter<String> lva = new ArrayAdapter<String>(
                getActivity(), android.R.layout.simple_list_item_1, awayStrings);
        lv.setAdapter(lva);

        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                if(position==0) {
                    Intent myintent = new Intent(view.getContext(), toptourist1.class);
                    startActivityForResult(myintent, 0);
                }
            }
        });

        final SwipeRefreshLayout mSwipeRefreshLayout = (SwipeRefreshLayout) view.findViewById(R.id.fragment_away);

        mSwipeRefreshLayout.setOnRefreshListener(
                new SwipeRefreshLayout.OnRefreshListener() {
                    @Override
                    public void onRefresh() {
                        ((MainActivity) getActivity()).refreshNow();
                        Toast.makeText(getContext(), "Refresh Layout working", Toast.LENGTH_LONG).show();

                    }
                }
        );

        return view;
    }

}

ViewPageAdapter

package com.example.computer.vratdragfinal;


import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

import java.util.ArrayList;

public class ViewPageAdapter extends FragmentPagerAdapter{

    ArrayList<Fragment> fragments = new ArrayList<>();
    ArrayList<String> tabTitles = new ArrayList<>();

    public void addFragments (Fragment fragments,String tabTitles){
        this.fragments.add(fragments);
        this.tabTitles.add(tabTitles);
    }

    public ViewPageAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getCount() {
        return fragments.size();
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return tabTitles.get(position);
    }
}

**WelcomeFragment**

package com.example.computer.vratdragfinal;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.google.vr.sdk.widgets.pano.VrPanoramaView;

public class WelcomeFragment extends Fragment {

    private VrPanoramaView panoWidgetView;
    private ImageLoaderTask backgroundImageLoaderTask;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v =  inflater.inflate(R.layout.welcome_fragment, container,false);
        panoWidgetView = (VrPanoramaView) v.findViewById(R.id.pano_view);
        return v;
    }

    @Override
    public void onPause() {
        panoWidgetView.pauseRendering();
        super.onPause();
    }

    @Override
    public void onResume() {
        panoWidgetView.resumeRendering();
        super.onResume();
    }

    @Override
    public void onDestroy() {

        panoWidgetView.shutdown();
        super.onDestroy();
    }

    private synchronized void loadPanoImage() {
        ImageLoaderTask task = backgroundImageLoaderTask;
        if (task != null && !task.isCancelled()) {
            task.cancel(true);
        }

        VrPanoramaView.Options viewOptions = new VrPanoramaView.Options();
        viewOptions.inputType = VrPanoramaView.Options.TYPE_STEREO_OVER_UNDER;

        String panoImageName = "converted.jpg";

        task = new ImageLoaderTask(panoWidgetView, viewOptions, panoImageName);
        task.execute(getActivity().getAssets());
        backgroundImageLoaderTask = task;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        loadPanoImage();
    }

}

生成

02/13 16:35:13: Launching app
$ adb shell am start -n "com.example.computer.vratdragfinal/com.example.computer.vratdragfinal.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Client not ready yet..Waiting for process to come online
Connected to process 7627 on device emulator-5554
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
W/art: Before Android 4.1, method int android.support.v7.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView
D/EGL_emulation: eglMakeCurrent: 0xae834b80: ver 2 0
E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008cdf
W/SdkConfigurationReader: VrParamsProvider returned null params, using defaults.
D/ConfigUtils: Parameters file not found for reading: java.io.FileNotFoundException: /storage/sdcard/Cardboard/current_device_params: open failed: ENOENT (No such file or directory)
I/GVR: [vr/gvr/capi/src/gvr.cc:94] Initialized GVR version 1.10.0
E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008cdf
W/art: Attempt to remove local handle scope entry from IRT, ignoring
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.computer.vratdragfinal, PID: 7627
                  java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.computer.vratdragfinal/com.example.computer.vratdragfinal.toptourist1}: java.lang.ClassCastException: com.example.computer.vratdragfinal.toptourist1 cannot be cast to android.app.Activity
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2236)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
                      at android.app.ActivityThread.access$800(ActivityThread.java:151)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:135)
                      at android.app.ActivityThread.main(ActivityThread.java:5254)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:372)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
                   Caused by: java.lang.ClassCastException: com.example.computer.vratdragfinal.toptourist1 cannot be cast to android.app.Activity
                      at android.app.Instrumentation.newActivity(Instrumentation.java:1066)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
                      at android.app.ActivityThread.access$800(ActivityThread.java:151) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:135) 
                      at android.app.ActivityThread.main(ActivityThread.java:5254) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:372) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
Application terminated.

Answer 1

你不能简单地说这里Activity是一个片段，不能使用Intent从一个片段重定向到另一个片段。 Intent用于在活动之间切换。这就是崩盘背后的原因。使用可以重定向到片段的机制，或者如果要使用intent，则需要使用活动而不是片段。