将在 RecyclerView 中单击的正确项目 position 返回到另一个活动

Question

I'm struggling with this problem for weeks and i always get (1) returned from RecyclerView

• i want to return the right item position clicked to SceneFormeActivity to be able to chose the correct object, but i'm getting the same "1" everytime so the same Case1'Object informations

my main class.kt code:

class ListeMeuble3DActivity : AppCompatActivity(),{
    var listMeubles = mutableListOf<Meuble>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_liste_meuble3_d)
         listMeubles = generateList()
        buildRecyclerView()
    }

    private fun generateList(): MutableList<Meuble>{

        val list = ArrayList<Meuble>()

           // to Add an Object Meuble(nom,prix,stock)

            val meuble = Meuble(R.drawable.fauteilgris, "Gris","25000da",1)
            val meuble1 = Meuble(R.drawable.fauteuille1, "","1000d&",1)
            val meuble2 = Meuble(R.drawable.burau, "Bureau","25000da",1)
            list.add(meuble)
            list.add(meuble1)
            list.add(meuble2)

        return list
    }

    fun buildRecyclerView() {
        mon_recycler.setHasFixedSize(true)
        //mon_recycler.setAdapter(mAdapter)
        mon_recycler.layoutManager = LinearLayoutManager(this)

        mon_recycler.adapter = MeubleAdapter(listMeubles.toTypedArray())
        {
            val intent3 = Intent(this, SceneformeActivity::class.java)
            intent3.putExtra("image_url",1)
            startActivity(intent3)
        }
     }
 }

My Adapter Class.kt:

class MeubleAdapter(private val exampleList: Array<Meuble>,val listener: (Meuble)-> Unit) :
    RecyclerView.Adapter<MeubleAdapter.ExampleViewHolder>() {
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ExampleViewHolder {
        val itemView = LayoutInflater.from(parent.context).inflate(R.layout.meuble_item,
            parent, false)
        return ExampleViewHolder(itemView)
    }
    override fun onBindViewHolder(holder: ExampleViewHolder, position: Int) {
        val currentItem = exampleList[position]
        holder.imageView.setImageResource(currentItem.imageResource)
        holder.textViewNomMeuble.text = currentItem.nom
        holder.textViewPrix.text = currentItem.prix
        holder.textViewStock.text = currentItem.stock.toString()

        holder.bind(exampleList[position],listener)
    }

    override fun getItemCount() = exampleList.size


    class ExampleViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(meuble:Meuble,listener: (Meuble) -> Unit)= with(itemView)
        {
            android.util.Log.i("XXXX","FCT Bind ")
            setOnClickListener{(listener(meuble))}
        }

        val imageView: ImageView = itemView.image_view
        val textViewNomMeuble: TextView = itemView.nomMeuble
        val textViewStock: TextView = itemView.stock
        val textViewPrix: TextView = itemView.prix

    }
}

My function in SceneFormeActivity.java where im supposed to get the item position

private void initializeGallery() {
        int imageUrl = getIntent().getIntExtra("image_url",0); // here, everytime it return 1
        LinearLayout gallery = findViewById(R.id.gallery_layout);
        int obj =imageUrl;
        switch (obj) {
            case 0: {
                ImageView andy = new ImageView(this);
                andy.setImageResource(R.drawable.fauteilgris);
                andy.setContentDescription("fauteuil Créme");
                andy.setOnClickListener(view ->{addObject(Uri.parse("foteuil.sfb"));});
                gallery.addView(andy);

            }
            break;
            case 1: {
                ImageView andy = new ImageView(this);
                andy.setImageResource(R.drawable.banc);
                andy.setContentDescription("banc extérieur");
                andy.setOnClickListener(view ->{addObject(Uri.parse("Bench.sfb"));});
                gallery.addView(andy);

            }
            break;
            case 2 : {
                ImageView andy = new ImageView(this);
                andy.setImageResource(R.drawable.burau);
                andy.setContentDescription("bureau");
                andy.setOnClickListener(view ->{addObject(Uri.parse("bureau.sfb"));});
                gallery.addView(andy);

            }
            break;
            case 3 : {
                ImageView andy = new ImageView(this);
                andy.setImageResource(R.drawable.fauteuille3);
                andy.setContentDescription("Fauteuil une place");
                andy.setOnClickListener(view ->{addObject(Uri.parse("ff.sfb"));});
                gallery.addView(andy);

            }
            break;
            default:Toast.makeText(getApplicationContext(),"Nothing",Toast.LENGTH_SHORT).show();

                break;

        }
    }

Answer 1

If all you really want is the position of the item then you don't need to send the Meuble on click at all. In your adapter change onBindViewHolder to:

override fun onBindViewHolder(holder: ExampleViewHolder, position: Int) {
        val currentItem = exampleList[position]
        holder.imageView.setImageResource(currentItem.imageResource)
        holder.textViewNomMeuble.text = currentItem.nom
        holder.textViewPrix.text = currentItem.prix
        holder.textViewStock.text = currentItem.stock.toString()

        holder.bind(position,listener)
    }

Setting your adapter should now look like this:

 mon_recycler.adapter = MeubleAdapter(listMeubles.toTypedArray()){ position ->
            val intent3 = Intent(this, SceneformeActivity::class.java)
            intent3.putExtra("image_url", position)
            startActivity(intent3)
        }

---

Edit: Expanding on the adapter usage:

Originally, you are passing two things to your Recyclerview Adapter -

1. The list of Meuble (There is no need to convert this to a TypedArray
2. The lambda that will act on the click of an item in the list

Consider the refactored code below with my inline comments. Note - it's not clear to me why you are sending position (assuming just to test?) So instead I'm assuming there is some imageURL in the object that you wish to send. I show below how you'd access that.

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_liste_meuble3_d)
    listMeubles = generateList()
    buildRecyclerView()
}

private fun generateList(): MutableList<Meuble>{

    val list = mutableListOf<Meuble>()

       // to Add an Object Meuble(nom,prix,stock)

        val meuble = Meuble(R.drawable.fauteilgris, "Gris","25000da",1)
        val meuble1 = Meuble(R.drawable.fauteuille1, "","1000d&",1)
        val meuble2 = Meuble(R.drawable.burau, "Bureau","25000da",1)
        list.add(meuble)
        list.add(meuble1)
        list.add(meuble2)

    return list
}

fun buildRecyclerView() {
    mon_recycler.setHasFixedSize(true)
    mon_recycler.layoutManager = LinearLayoutManager(this)

    // NOTE: Here the lambda implicitly had an item of type Meuble passed.  We name it here but could have just used "it".
    mon_recycler.adapter = MeubleAdapter(listMeubles.toTypedArray())
    { item ->
        val intent3 = Intent(this, SceneformeActivity::class.java)
        intent3.putExtra("image_url",item.imageUrl)
        startActivity(intent3)
    }
 }

} My Adapter Class.kt:

// Don't need to pass as a TypedArray - List is fine
class MeubleAdapter(private val exampleList: List<Meuble>,val listener: (Meuble)-> Unit) :
    RecyclerView.Adapter<MeubleAdapter.ExampleViewHolder>() {
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ExampleViewHolder {
        val itemView = LayoutInflater.from(parent.context).inflate(R.layout.meuble_item,
            parent, false)
        return ExampleViewHolder(itemView)
    }
    override fun onBindViewHolder(holder: ExampleViewHolder, position: Int) {
        val currentItem = exampleList[position]
        holder.imageView.setImageResource(currentItem.imageResource)
        holder.textViewNomMeuble.text = currentItem.nom
        holder.textViewPrix.text = currentItem.prix
        holder.textViewStock.text = currentItem.stock.toString()

        holder.bind(exampleList[position],listener)
    }

    override fun getItemCount() = exampleList.size


    class ExampleViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(meuble:Meuble,listener: (Meuble) -> Unit)= with(itemView)
        {
            android.util.Log.i("XXXX","FCT Bind ")
            setOnClickListener{(listener(meuble))}
        }

        val imageView: ImageView = itemView.image_view
        val textViewNomMeuble: TextView = itemView.nomMeuble
        val textViewStock: TextView = itemView.stock
        val textViewPrix: TextView = itemView.prix

    }
}

Answer 2

So i used this solution,, i passed the name (nom) of my clicked object to the SceneFormActivity to get the reference and display my 3D object in the next activity:

code from main

   val intent3 = Intent(this, SceneformeActivity::class.java)
            intent3.putExtra("image_url",it.nom) //  it.nom to get the name of the object clicked
            startActivity(intent3)

and in SceneformeActivity:

 private void initializeGallery() {
        String imageUrl = getIntent().getStringExtra("image_url"); // changed this from getInt to getString to get the name
        LinearLayout gallery = findViewById(R.id.gallery_layout);
        String obj =imageUrl;   
        switch (obj) {
            case "fauteilgris": { // case "String": the name of the object clicked in the previous activity(RecyclerView)
                ImageView andy = new ImageView(this);
                andy.setImageResource(R.drawable.fauteilgris);
                andy.setContentDescription("fauteuil Créme");
                andy.setOnClickListener(view ->{addObject(Uri.parse("foteuil.sfb"));});
                gallery.addView(andy);

            }
            break;
            case "banc": {
                ImageView andy = new ImageView(this);
                andy.setImageResource(R.drawable.banc);
                andy.setContentDescription("banc extérieur");
                andy.setOnClickListener(view ->{addObject(Uri.parse("Bench.sfb"));});
                gallery.addView(andy);

            }
            break;
            case "burau": {
                ImageView andy = new ImageView(this);
                andy.setImageResource(R.drawable.burau);
                andy.setContentDescription("bureau");
                andy.setOnClickListener(view ->{addObject(Uri.parse("bureau.sfb"));});
                gallery.addView(andy);

            }
            break;
 default:Toast.makeText(getApplicationContext(),"No Object",Toast.LENGTH_SHORT).show();

                break;

        }
    }