Android 毕加索未将图像从Firebase存储加载到RecyclerView

我正试图通过毕加索图书馆从Firebase存储中获取图像，并将其显示在回收视图上

我也尝试过使用其他库（如Glide和Fresco）加载图像，但仍然没有显示图像

请在下面查找此应用程序的代码：

BlogRecyclerAdapter.java：

public BlogRecyclerAdapter(Context context, List<Blog> blogList) {
        this.context = context;
        this.blogList = blogList;
        this.firebaseStorage = firebaseStorage;
    }
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.post_row, parent, false);

        return new ViewHolder(view, context);
    }

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

        Blog blog = blogList.get(position);
        //String imageUrl = null;

        holder.title.setText(blog.getTitle());
        holder.desc.setText(blog.getDesc());


        DateFormat dateFormat = DateFormat.getDateInstance();
        String formattedDate = dateFormat.format(new Date(Long.valueOf(blog.getTimestamp())).getTime());

        holder.timestamp.setText(formattedDate);

        String imageUrl = blog.getImage();

        //TODO: Use Picasso library to load image

        Picasso.get()
                .load(imageUrl)
                .into(holder.image);
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        public TextView title;
        public TextView desc;
        public TextView timestamp;
        public ImageView image;
        String userid;

        public ViewHolder(View view, Context ctx) {
            super(view);


            title = (TextView) view.findViewById(R.id.postTitleList);
            desc = (TextView) view.findViewById(R.id.postTextList);
            image = (ImageView) view.findViewById(R.id.postImageList);
            timestamp = (TextView) view.findViewById(R.id.timestampList);

            userid = null;

            view.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    // we can go to the next activity...

                }
            });

        }
    }
}

post_row.xml：

<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:fresco="http://schemas.android.com/apk/res-auto"
    android:layout_margin="5dp">



    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">


        <ImageView
            android:id="@+id/postImageList"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:adjustViewBounds="true"
            android:cropToPadding="false"
            android:scaleType="centerCrop"
            android:src="@mipmap/add_btn"/>


        <TextView
            android:id="@+id/postTitleList"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:text="Post Title"
            android:textSize="18sp"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/postTextList"
            android:paddingLeft="15dp"
            android:paddingRight="15dp"
            android:paddingTop="15dp"
            android:padding="10dp"
            android:text="Post Description Here"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/timestampList"
            android:text="Date Created"
            android:padding="5dp"
            android:textStyle="italic"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </LinearLayout>

</android.support.v7.widget.CardView>

在运行代码时，我还遇到以下错误消息：

E/RecyclerView：未连接适配器；跳过布局

---

如果您发现我的代码有问题，请告诉我，我将期待您的回复。

您的childlistner似乎不起作用。尝试ValueEventListener而不是ChildEventListener。通过firebase了解更多关于听众的信息

---

问题在于事件的执行顺序-需要在onCreate中将适配器设置为recycler视图。毕竟，这可能不是图像库的问题

我希望您能理解，重新创建问题很困难，因为我需要创建一个测试Firebase数据库等，并100%确定答案。我强烈建议重新安排适配器代码

1将这两行移到PostListActivity中onCreate的底部：

  blogRecyclerAdapter = new BlogRecyclerAdapter(PostListActivity.this, blogList);
            recyclerView.setAdapter(blogRecyclerAdapter);

2向BlogRecyclerAdapter类添加一个方法，该方法允许更新设置到适配器的项：

public void updateBlogList(ArrayList<Blog> newBlogs){
this.blogList = newBlogs;
notifyDataSetChanged();  }

正如我所说，很难重新创建问题，代码中可能还有其他问题，但希望这能解决E/RecyclerView：没有连接适配器；跳过布局错误

此外，Glide似乎是从外部源加载图像的强大库。在我的一个项目中，我能够使用以下代码在onBind In适配器中加载图像：

 mFirebaseDatabase = FirebaseDatabase.getInstance();
    mRef = mFirebaseDatabase.getReference(Constants.USERS_PATH).child(offeredRoute.getUserID());
    mFirebaseStorage = FirebaseStorage.getInstance();
    mStorageReference = mFirebaseStorage.getReference().child(Constants.IMAGES_PATH).child(offeredRoute.getUserID());

//download all other values
mRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
        mUserProfile = dataSnapshot.getValue(UserProfile.class);
        //set data to views
        if (mUserProfile != null) {
            holder.resultUsernameTv.setText(mUserProfile.getUser());

            if (mUserProfile.getPhotoUrl() == null || mUserProfile.getPhotoUrl().isEmpty()) {
                Timber.v("No photo saved yet");
            } else {
                StorageReference downloadRef = mStorageReference.child(mUserProfile.getPhotoUrl());
                Glide.with(mContext)
                        .using(new FirebaseImageLoader())
                        .load(downloadRef)
                        .into(holder.ImageViewRv);
            }
        }
    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {

    }
});

---

谢谢

给我图像url，我会检查加载问题，首先设置适配器，然后获取列表，然后通过适配器中的getter和setter设置新列表，并调用notifydatasetchangedchange android:layout\u height=match\u parent to android:layout\u height=wrap\u内容在您的recyclerview中。我正在尝试从firebase存储中获取许多图像，而不仅仅是一个，那么我应该给你什么url呢？谢谢你的回答，但是当我运行你的代码时，应用程序崩溃了；跳过布局会消失，但图像仍然不可见。日志现在怎么说？另外，你在build.gradle中有哪些依赖项？我已经在问题中添加了build.gradle文件；保存在您的Firebase存储规则中？您的build.gradle中有实现com.firebaseui:firebaseui存储：4.3.x的副本

apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.myblogapp"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }


    dependencies {
        implementation fileTree(dir: 'libs', include: ['*.jar'])
        implementation 'com.android.support:appcompat-v7:28.0.0'
        implementation 'com.android.support.constraint:constraint-layout:1.1.3'
        implementation 'com.google.firebase:firebase-core:16.0.8'
        implementation 'com.google.firebase:firebase-core:16.0.8'
        implementation 'com.google.firebase:firebase-database:16.1.0'
        implementation 'com.firebaseui:firebase-ui-storage:4.3.1'
        implementation 'com.google.firebase:firebase-auth:16.2.0'
        implementation 'com.google.firebase:firebase-storage:16.0.4'
        implementation 'com.github.bumptech.glide:glide:3.7.0'
        testImplementation 'junit:junit:4.12'
        androidTestImplementation 'com.android.support.test:runner:1.0.2'
        androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
        implementation 'com.android.support:recyclerview-v7:28.0.0'
        implementation 'com.android.support:cardview-v7:28.0.0'
        implementation 'com.squareup.picasso:picasso:2.71828'
        implementation 'com.theartofdev.edmodo:android-image-cropper:2.4.+'
        implementation 'com.facebook.fresco:fresco:1.10.0'
        implementation 'com.firebaseui:firebase-ui-storage:4.3.2'
    }


    apply plugin: 'com.google.gms.google-services'
}

mDatabaseReference.addValueEventListener(new ValueEventListener() {
  @Override
  public void onDataChange(DataSnapshot dataSnapshot) {
    for (DataSnapshot data : dataSnapshot.getChildren()){
       Blog blog = dataSnapshot.getValue(Blog.class);
       blogList.add(blog);
    }
    Collections.reverse(blogList);
    blogRecyclerAdapter = new BlogRecyclerAdapter(PostListActivity.this, blogList);
    recyclerView.setAdapter(blogRecyclerAdapter);
  }

  @Override
  public void onCancelled(DatabaseError databaseError) {
    System.out.println("The read failed: " + databaseError.getCode());
  }
});

  blogRecyclerAdapter = new BlogRecyclerAdapter(PostListActivity.this, blogList);
            recyclerView.setAdapter(blogRecyclerAdapter);

public void updateBlogList(ArrayList<Blog> newBlogs){
this.blogList = newBlogs;
notifyDataSetChanged();  }

Blog blog = dataSnapshot.getValue(Blog.class);

blogList.add(blog);

Collections.reverse(blogList);

blogRecyclerAdapter.updateBlogList(blogList); 

 mFirebaseDatabase = FirebaseDatabase.getInstance();
    mRef = mFirebaseDatabase.getReference(Constants.USERS_PATH).child(offeredRoute.getUserID());
    mFirebaseStorage = FirebaseStorage.getInstance();
    mStorageReference = mFirebaseStorage.getReference().child(Constants.IMAGES_PATH).child(offeredRoute.getUserID());

//download all other values
mRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
        mUserProfile = dataSnapshot.getValue(UserProfile.class);
        //set data to views
        if (mUserProfile != null) {
            holder.resultUsernameTv.setText(mUserProfile.getUser());

            if (mUserProfile.getPhotoUrl() == null || mUserProfile.getPhotoUrl().isEmpty()) {
                Timber.v("No photo saved yet");
            } else {
                StorageReference downloadRef = mStorageReference.child(mUserProfile.getPhotoUrl());
                Glide.with(mContext)
                        .using(new FirebaseImageLoader())
                        .load(downloadRef)
                        .into(holder.ImageViewRv);
            }
        }
    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {

    }
});