如何使用毕加索将我的 Firebase 数据库中的图像放到我的 RecyclerView 上？

Question

I want to populate my RecyclerView with images that I have on my firebase database. I am using Groupie for my RecyclerView adapter. My adapter class looks like this

class HobbiesAdapter(val hobbyItem: HobbiesClass): Item<GroupieViewHolder>(){
        override fun bind(viewHolder: GroupieViewHolder, position: Int) {

                viewHolder.itemView.hobbynameTV.text = hobbyItem.hobbyName
                //viewholder.itemView.hobbyImageView ...

        }

        override fun getLayout(): Int {
              return  R.layout.row
        }
}
@Parcelize
class HobbiesClass (val hobbyName:String):Parcelable{
        constructor():this("")
}

Here is my RecyclerView item row xml file:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="164dp"
    android:layout_height="70dp"
    android:layout_marginStart="5dp"
    android:background="@android:color/transparent"
    xmlns:android="http://schemas.android.com/apk/res/android">
        <FrameLayout
            android:id="@+id/frameHobby"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@drawable/hobbiesbackground">
                <TextView
                    android:id="@+id/hobbynameTV"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Camping"
                    android:textColor="#000000"
                    android:fontFamily="@font/extralight"
                    android:layout_gravity="center|right"
                    android:layout_marginEnd="15dp"/>

                <de.hdodenhof.circleimageview.CircleImageView
                    android:id="@+id/hobbyImageView"
                    android:layout_width="54dp"
                    android:layout_height="47dp"
                    android:layout_gravity="center|left"
                    android:layout_marginStart="12dp"/>


        </FrameLayout>


</androidx.constraintlayout.widget.ConstraintLayout>

I can retrieve hobbies names by this piece of code here

val reference = database.getReference("Hobbies")
reference.addValueEventListener(object : ValueEventListener {
    override fun onDataChange(snapshot: DataSnapshot) {
        val adapter = GroupAdapter<GroupieViewHolder>()
        for (snap in snapshot.children) {
            val hobbiesItem = snap.getValue(HobbiesClass::class.java)
            if (hobbiesItem != null) {
                adapter.add(HobbiesAdapter(hobbiesItem))

            }
        }

        tophobbies.adapter = adapter
    }

    override fun onCancelled(error: DatabaseError) {

    }


})

Here is my Realtime Database

I tried putting this code block under adapter.add(HobbiesAdapter(hobbiesItem))

for (dataSnapshot in snapshot.children){
    var map = dataSnapshot.getValue() as Map<String,Object>
    val imageLink = map.get("imageUrl") as String
    Picasso.get().load(imageLink).into(hobbyImageView)
}

But it only put image to my first item in my RecyclerView also its not the correct image. Here is how my app looks like after I launch it

Answer 1

Your problem is here:

if (hobbiesItem != null) {
            adapter.add(HobbiesAdapter(hobbiesItem))

        }

Here you are passing one hobbiesItem, and not a list of hobbiesItem to the Adapter.

1. Create a global list of type hobbiesItem.
2. Replace the adapter.add(HobbiesAdapter(hobbiesItem)) to exampleList.add(HobbiesAdapter(hobbiesItem))
3. And then pass this exampleList to the adapter like this: adapter.add(exampleList).

The adapter should accept a list of hobbiesItem. And onDataChange should pass that list to the adapter.

Answer 2

I have found a solution. It was the first thing I wanted to do. But I was just missing something. What I did I added new string parameter to HobbiesClass class called imageUrl(this has to be the same name with the name of your key in your Firebase database)

Hobbies class

@Parcelize
class HobbiesClass (val hobbyName:String,val imageUrl:String):Parcelable{
        constructor():this("","")
}

Then I added

Picasso.get().load(hobbyItem.imageUrl).into(viewHolder.itemView.hobbyImageView)

In my bind method of my HobbiesAdapter class. I did not change anything in my Hobbies class. Now it works perfectly fine.