Android Studio：无法启动活动ComponentInfo：java.lang.illegalStateException：RecyclerVIew没有LayoutMAnager

Question

我是android studio的新手。我目前正在为我的学校项目开发一个应用程序，遇到一个我试图寻找解决方案的问题，但无济于事。这是我的错误。请帮我谢谢你！

07-02 16:24:05.882 27824-27824/? E/AndroidRuntime: FATAL EXCEPTION: main

java.lang.RuntimeException: Unable to start activity ComponentInfo{sg.edu.tp.moviereviewflexiv21/sg.edu.tp.moviereviewflexiv21.activities.HomePagePrototype}: java.lang.IllegalStateException: RecyclerView has no LayoutManager android.support.v7.widget.RecyclerView{22d56d58 VFED.... ......I. 0,0-0,0 #7f08009c app:id/recyclerview_trending}, adapter:null, layout:null, context:sg.edu.tp.moviereviewflexiv21.activities.HomePagePrototype@3e90d3d1
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
    at android.app.ActivityThread.access$800(ActivityThread.java:144)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5221)
    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:899)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
 Caused by: java.lang.IllegalStateException: RecyclerView has no LayoutManager android.support.v7.widget.RecyclerView{22d56d58 VFED.... ......I. 0,0-0,0 #7f08009c app:id/recyclerview_trending}, adapter:null, layout:null, context:sg.edu.tp.moviereviewflexiv21.activities.HomePagePrototype@3e90d3d1
    at android.support.v7.widget.RecyclerView.generateLayoutParams(RecyclerView.java:4192)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:808)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
    at android.view.LayoutInflater.parseInclude(LayoutInflater.java:916)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:802)
    at android.view.LayoutInflater.parseInclude(LayoutInflater.java:916)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:802)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
    at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:287)
    at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
    at sg.edu.tp.moviereviewflexiv21.activities.HomePagePrototype.onCreate(HomePagePrototype.java:34)
    at android.app.Activity.performCreate(Activity.java:5937)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251) 

这是我的RecyclerViewAdapter2.java：

public class RecyclerVIewAdapter2 extends RecyclerView.Adapter<RecyclerVIewAdapter2.ViewHolder> {

private static final String TAG = "RecyclerVIewAdapter2";

//vars
private ArrayList<String> mNames = new ArrayList<>();
private ArrayList<String> mImageUrls = new ArrayList<>();
private Context mContext;

public RecyclerVIewAdapter2(Context mContext, ArrayList<String> mNames, ArrayList<String> mImageUrls) {
    this.mNames = mNames;
    this.mImageUrls = mImageUrls;
    this.mContext = mContext;
}

@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) 
{

    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_listitem, parent, false);
    return new ViewHolder(view);

}

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, final int position) {

    Glide.with(mContext)
            .asBitmap()
            .load(mImageUrls.get(position))
            .into(holder.image);

    holder.name.setText(mNames.get(position));

    holder.image.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d(TAG, "onClick: Clicked on an image: " + mNames.get(position));
            Toast.makeText(mContext, mNames.get(position), Toast.LENGTH_SHORT).show();
        }
    });

}

@Override
public int getItemCount() {
    return mImageUrls.size();
}

public class ViewHolder extends RecyclerView.ViewHolder{

    ImageView image;
    TextView name;

    public ViewHolder(View itemView) {
        super(itemView);
        image = itemView.findViewById(R.id.imageofmovie);
        name = itemView.findViewById(R.id.nameofmovie);
    }
}


}

这是我的AndroidManifest.xml：

<?xml version="1.0" encoding="utf-8"?>

<uses-permission android:name="android.permission.INTERNET" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/flexireview"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/flexireview_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".activities.Splash">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".activities.SignIn" />
    <activity android:name=".activities.NavigationDrawer" />
    <activity
        android:name=".activities.TestingBurgerMenu"
        android:label="@string/title_activity_home_page"
        android:theme="@style/AppTheme" />
    <activity
        android:name=".HomePageBottomNav"
        android:label="@string/title_activity_home_page_bottom_nav" />
    <activity android:name=".BottomBarNavTesting" />
    <activity
        android:name=".activities.HomePagePrototype"
        android:label="@string/title_activity_home_page_prototype"
        android:theme="@style/AppTheme"></activity>
</application>

</manifest>

这是我的styles.xml：

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="coordinatorLayoutStyle">@style/Widget.Design.CoordinatorLayout</item>
</style>

<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

这是我的整个HomePagePrototype.java文件，通常称为MainActivity.java：

public class HomePagePrototype extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

//vars
private ArrayList<String> mNames = new ArrayList<>();
private ArrayList<String> mImageUrls = new ArrayList<>();

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

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.addDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);

    getImages();
}

private void getImages(){
    mImageUrls.add("https://image.tmdb.org/t/p/original/c9XxwwhPHdaImA2f1WEfEsbhaFB.jpg");
    mNames.add("Jurassic World:Fallen Kingdom");

    mImageUrls.add("https://image.tmdb.org/t/p/original/x1txcDXkcM65gl7w20PwYSxAYah.jpg");
    mNames.add("Incredibles 2");

    mImageUrls.add("https://image.tmdb.org/t/p/original/rzRwTcFvttcN1ZpX2xv4j3tSdJu.jpg");
    mNames.add("Thor: Ragnarok");

    mImageUrls.add("https://image.tmdb.org/t/p/original/3gIO6mCd4Q4PF1tuwcyI3sjFrtI.jpg");
    mNames.add("Rampage (2018)");

    mImageUrls.add("https://image.tmdb.org/t/p/original/7WsyChQLEftFiDOVTGkv3hFpyyt.jpg");
    mNames.add("Avengers: Infinity War");

    mImageUrls.add("https://image.tmdb.org/t/p/original/jjPJ4s3DWZZvI4vw8Xfi4Vqa1Q8.jpg");
    mNames.add("Fifty Shades Freed");

    mImageUrls.add("https://image.tmdb.org/t/p/original/jjBgi2r5cRt36xF6iNUEhzscEcb.jpg");
    mNames.add("Jurassic World (2015)");

    mImageUrls.add("https://image.tmdb.org/t/p/original/v5HlmJK9bdeHxN2QhaFP1ivjX3U.jpg");
    mNames.add("Pacific Rim: Uprising (2018)");

    mImageUrls.add("https://image.tmdb.org/t/p/original/uxzzxijgPIY7slzFvMotPv8wjKA.jpg");
    mNames.add("Black Panther (2018)");

    mImageUrls.add("https://image.tmdb.org/t/p/original/pU1ULUq8D3iRxl1fdX2lZIzdHuI.jpg");
    mNames.add("Ready Player One (2018)");

}

private void initRecyclerView(){
    LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
    RecyclerView recyclerView = findViewById(R.id.recyclerview_trending);
    recyclerView.setLayoutManager(layoutManager);
    RecyclerVIewAdapter2 adapter = new RecyclerVIewAdapter2(this, mNames, mImageUrls);
    recyclerView.setAdapter(adapter);

}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

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

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.nav_camera) {
        // Handle the camera action
    } else if (id == R.id.nav_gallery) {

    } else if (id == R.id.nav_slideshow) {

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.nav_share) {

    } else if (id == R.id.nav_send) {

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}
}

我正在recyclerview上观看以下视频：https://www.youtube.com/watch?v=94rCjYxvzEE

Answer 1

这是一个模糊的问题，但确实指出了“ RecyclerView没有LayoutManager”的错误。您可以通过Google获得大量支持。以下是您可能尝试实现的示例教程。

Example Tutorial

Answer 2

我修复了它。显然问题出在我的XML文件中，我将recyclerview设置为XML中的按钮和其他textView的父级。为了解决这个问题，我从recyclerview部分中删除了所有孩子。