Question

我从firebase实时数据库中获取图像时遇到问题。图像存储在存储中，我在数据库中有一个链接，但是当我尝试将图像显示在recyclerview中时，应用程序在尝试加载记录时崩溃。我在gradle.app中添加了依赖项，并且已经使用了Internet

获取数据的代码

@Override
public void onBindViewHolder(RestaurantViewHolder holder, int position) {
    Restaurant restaurant = restaurantList.get(position);

    holder.title.setText(restaurant.getTitle());
    holder.address.setText(restaurant.getAddress());
    holder.cuisine.setText(restaurant.getCuisine());
    holder.duration.setText(restaurant.getDuration());
    holder.PriceRange.setText(restaurant.getPriceRange());

    Picasso.with(context).load(restaurantList.get(position).getImage()).resize(120,90).into(holder.imageView);
}

设置数据的代码

public class RestaurantViewHolder extends RecyclerView.ViewHolder{

    TextView title, address, cuisine, duration, PriceRange;
    ImageView imageView;

    public RestaurantViewHolder(View itemView) {
        super(itemView);

        title = itemView.findViewById(R.id.textViewTitle);
        address = itemView.findViewById(R.id.textViewAddress);
        cuisine = itemView.findViewById(R.id.textViewCuisine);
        duration = itemView.findViewById(R.id.textViewDuration);
        PriceRange = itemView.findViewById(R.id.textViewPriceRange);
        imageView = itemView.findViewById(R.id.viewImage);

    }
}

设置/获取方法

public class Restraunt{

public Restaurant(String image) {
    this.image = image;
}
    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }
}

崩溃日志

04-20 20:30:14.528 30759-30759/nci.wherenow E/AndroidRuntime: FATAL EXCEPTION: main
Process: nci.wherenow, PID: 30759
java.lang.IllegalArgumentException: Context must not be null.
    at com.squareup.picasso.Picasso$Builder.<init>(Picasso.java:701)
    at com.squareup.picasso.Picasso.with(Picasso.java:662)
    at nci.wherenow.RestaurantAdapter.onBindViewHolder(RestaurantAdapter.java:48)
    at nci.wherenow.RestaurantAdapter.onBindViewHolder(RestaurantAdapter.java:19)
    at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6482)
    at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6515)
    at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5458)
    at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5724)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5563)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5559)
    at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2229)
    at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1556)
    at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1516)
    at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:608)
    at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3693)
    at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3109)
    at android.view.View.measure(View.java:22104)
    at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:934)
    at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:973)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:400)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at com.android.internal.policy.DecorView.onMeasure(DecorView.java:722)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2441)
    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1522)
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1775)
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1410)
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6834)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:966)
    at android.view.Choreographer.doCallbacks(Choreographer.java:778)
    at android.view.Choreographer.doFrame(Choreographer.java:713)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:952)
    at android.os.Handler.handleCallback(Handler.java:789)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6809)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

更新了崩溃日志：

04-20 20:37:12.153 855-855/nci.wherenow E/AndroidRuntime: FATAL EXCEPTION: main
Process: nci.wherenow, PID: 855
com.google.firebase.database.DatabaseException: Class nci.wherenow.Restaurant does not define a no-argument constructor. If you are using ProGuard, make sure these constructors are not stripped.
    at com.google.android.gms.internal.zzelx.zze(Unknown Source:45)
    at com.google.android.gms.internal.zzelw.zzb(Unknown Source:198)
    at com.google.android.gms.internal.zzelw.zza(Unknown Source:0)
    at com.google.firebase.database.DataSnapshot.getValue(Unknown Source:10)
    at nci.wherenow.Restaurant_Results$1.onChildAdded(Restaurant_Results.java:58)
    at com.google.android.gms.internal.zzecw.zza(Unknown Source:71)
    at com.google.android.gms.internal.zzeia.zzbyc(Unknown Source:2)
    at com.google.android.gms.internal.zzeig.run(Unknown Source:71)
    at android.os.Handler.handleCallback(Handler.java:789)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6809)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
04-20 20:37:12.154 855-855/nci.wherenow E/UncaughtException: com.google.firebase.database.DatabaseException: Class nci.wherenow.Restaurant does not define a no-argument constructor. If you are using ProGuard, make sure these constructors are not stripped.
    at com.google.android.gms.internal.zzelx.zze(Unknown Source:45)
    at com.google.android.gms.internal.zzelw.zzb(Unknown Source:198)
    at com.google.android.gms.internal.zzelw.zza(Unknown Source:0)
    at com.google.firebase.database.DataSnapshot.getValue(Unknown Source:10)
    at nci.wherenow.Restaurant_Results$1.onChildAdded(Restaurant_Results.java:58)
    at com.google.android.gms.internal.zzecw.zza(Unknown Source:71)
    at com.google.android.gms.internal.zzeia.zzbyc(Unknown Source:2)
    at com.google.android.gms.internal.zzeig.run(Unknown Source:71)
    at android.os.Handler.handleCallback(Handler.java:789)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6809)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

崩溃更新2

04-20 20:45:41.030 4227-4227/nci.wherenow E/AndroidRuntime: FATAL EXCEPTION: main
Process: nci.wherenow, PID: 4227
java.lang.IllegalArgumentException: Context must not be null.
    at com.squareup.picasso.Picasso$Builder.<init>(Picasso.java:701)
    at com.squareup.picasso.Picasso.with(Picasso.java:662)
    at nci.wherenow.RestaurantAdapter.onBindViewHolder(RestaurantAdapter.java:48)
    at nci.wherenow.RestaurantAdapter.onBindViewHolder(RestaurantAdapter.java:19)
    at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6482)
    at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6515)
    at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5458)
    at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5724)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5563)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5559)
    at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2229)
    at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1556)
    at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1516)
    at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:608)
    at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3693)
    at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3109)
    at android.view.View.measure(View.java:22104)
    at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:934)
    at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:973)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:400)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6584)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
    at com.android.internal.policy.DecorView.onMeasure(DecorView.java:722)
    at android.view.View.measure(View.java:22104)
    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2441)
    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1522)
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1775)
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1410)
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6834)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:966)
    at android.view.Choreographer.doCallbacks(Choreographer.java:778)
    at android.view.Choreographer.doFrame(Choreographer.java:713)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:952)
    at android.os.Handler.handleCallback(Handler.java:789)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6809)
    at java.lang.reflect.Method.invoke(Native Method)
04-20 20:45:41.031 4227-4227/nci.wherenow E/AndroidRuntime:     at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

Answer 1

//在模型中声明你的餐厅空构造函数;

Restaurant.java

public Restaurant() {
    }
public String getImage() {
return image;
}

public void setImage(String image) {
    this.image = image;
}

主要课程： - 替换你的代码onBindViewHolder

Restaurant restaurant = new Restaurant();
Picasso.with(getContext()).load(restaurant.getImage()).resize(200, 200).into(holder. 
imageView);

Answer 2

在您的活动中试试这个，通过＆＃39;这个＆＃39;适配器如：

RecyclerAdapter r = new  RecyclerAdapter(this);

然后在您的RecyclerAdapter类构造函数中：

Context context; // global
public RecyclerAdapter(Context context){
this.context = context;
}

Answer 3

您的上下文为空，这是问题，尝试将上下文从活动（您将适配器添加到回收器视图的位置）传递到RestaurantAdapter（到构造函数）并将其与picasso一起使用。

在您的活动中使用getBaseContext（）（您创建了Restaurent适配器的实例）并将其传递给适配器构造函数并在picasso中使用它。

Answer 4

您只需要初始化上下文。您可以将它传递给适配器构造函数，如上所述。或者，您可以在Application类中定义静态上下文，并在Application类onCreate方法中初始化它。但第一个更有可能。

如何使用Picasso将Firebase中的图像转换为RecyclerView

4 个答案: