getting null error on passing object list to spinner

[Miteshmakwana73]

error

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.gueyedeapp, PID: 13713
    java.lang.ClassCastException: c.c.a.g.e.a.a$a cannot be cast to java.lang.CharSequence
        at c.g.a.b.z(:43)
        at c.g.a.b.m(:26)
        at androidx.recyclerview.widget.RecyclerView$g.n(:7065)
        at androidx.recyclerview.widget.RecyclerView$g.d(:7107)
        at androidx.recyclerview.widget.RecyclerView$u.F(:6012)
        at androidx.recyclerview.widget.RecyclerView$u.G(:6279)
        at androidx.recyclerview.widget.RecyclerView$u.p(:6118)
        at androidx.recyclerview.widget.RecyclerView$u.o(:6114)
        at androidx.recyclerview.widget.LinearLayoutManager$c.d(:2303)
        at androidx.recyclerview.widget.LinearLayoutManager.r2(:1627)
        at androidx.recyclerview.widget.LinearLayoutManager.U1(:1587)
        at androidx.recyclerview.widget.LinearLayoutManager.X0(:665)
        at androidx.recyclerview.widget.RecyclerView.D(:4134)
        at androidx.recyclerview.widget.RecyclerView.onMeasure(:3540)
        at android.view.View.measure(View.java:17765)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5620)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:454)
        at android.view.View.measure(View.java:17765)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2349)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1373)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1597)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1251)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6438)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:795)
        at android.view.Choreographer.doCallbacks(Choreographer.java:598)
        at android.view.Choreographer.doFrame(Choreographer.java:567)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:781)
        at android.os.Handler.handleCallback(Handler.java:810)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:189)
        at android.app.ActivityThread.main(ActivityThread.java:5532)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:950)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:745)

this what i done so far

xml

<com.skydoves.powerspinner.PowerSpinnerView
                    android:id="@+id/spinnerCategory"
                    style="@style/fontRegular"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:gravity="center_vertical"
                    android:layout_marginStart="@dimen/_10sdp"
                    android:layout_marginTop="@dimen/_20sdp"
                    android:layout_marginEnd="@dimen/_10sdp"
                    android:background="@drawable/background_button_white_20dp"
                    android:drawableEnd="@drawable/ic_search_gray"
                    android:drawablePadding="@dimen/_7sdp"
                    android:elevation="1dp"
                    android:hint="@string/category"
                    android:padding="@dimen/_9sdp"
                    android:textColor="@color/black"
                    android:textSize="@dimen/_12ssp"
                    app:spinner_arrow_gravity="end"
                    app:spinner_arrow_padding="8dp"
                    app:spinner_divider_color="@color/black"
                    app:spinner_divider_show="true"
                    app:spinner_divider_size="0.4dp"
                    app:spinner_popup_animation="dropdown"
                    app:spinner_popup_elevation="14dp" />

java

override fun setCategoryList(response: CategoryListModel) {
        activity?.hideKeybord()
        hideProgressBar()
        mList.clear()
        mList.addAll(response.data)
        binding.spinnerCategory.apply {
            setItems(mList)
            setOnSpinnerItemSelectedListener<CategoryListModel.CategoryListData> { _, item ->
                binding.spinnerCategory.hint = item.categoryName
                Toast.makeText(context, item.categoryName, Toast.LENGTH_SHORT).show()
            }
            lifecycleOwner = this@SearchFragment
            preferenceName = getString(R.string.category)
        }
}

I am setting spinner when I get a response from API

this is my model class

import com.google.gson.annotations.SerializedName

data class CategoryListModel(
    @SerializedName("data")
    val `data`: List<CategoryListData> = listOf(),
    @SerializedName("FLAG")
    val fLAG: Boolean = false,
    @SerializedName("IS_ACTIVE")
    val iSACTIVE: Int = 0,
    @SerializedName("MESSAGE")
    val mESSAGE: String = ""
) {
    data class CategoryListData(
        @SerializedName("category_name")
        val categoryName: String = "",
        @SerializedName("created_by")
        val createdBy: String = "",
        @SerializedName("created_date")
        val createdDate: String = "",
        @SerializedName("id")
        val id: String = "",
        @SerializedName("modified_by")
        val modifiedBy: String = "",
        @SerializedName("modified_date")
        val modifiedDate: String = "",
        @SerializedName("status")
        val status: String = ""
    )
}

please suggest me why I am getting an error

[skydoves]

Hi, It seems to use a default adapter. The default adapter can be set only Charsequence type items. So If you want to use your custom model as a data list, create a new custom adapter.

[Miteshmakwana73]

can you provide a full custom adapter class so everyone understands better and proper or any example?

[skydoves]

This is an example. The customized adapter is not much different from the RecyclerView.Adapter because a customized adapter must extend it. The main difference is implementing the PowerSpinnerInterface interface. You can reference this example codes.

[Miteshmakwana73]

thank you it's working now this is my code of the custom adapter so anyone can take reference from it.

bind spinner

binding.spinnerCategory.apply {
            setSpinnerAdapter(MySpinnerAdapter(this))
            setItems(mList)
            setOnSpinnerItemSelectedListener<CategoryListModel.CategoryListData> { _, item ->
                binding.spinnerCategory.hint = item.categoryName
                Toast.makeText(context, item.categoryName, Toast.LENGTH_SHORT).show()
            }
            lifecycleOwner = this@SearchFragment
            preferenceName = getString(R.string.category)
        }

adapter

inner class MySpinnerAdapter(
        powerSpinnerView: PowerSpinnerView
    ) : RecyclerView.Adapter<MySpinnerAdapter.ViewHolder>(),
        PowerSpinnerInterface<CategoryListModel.CategoryListData> {

        override val spinnerView: PowerSpinnerView = powerSpinnerView
        override var onSpinnerItemSelectedListener: OnSpinnerItemSelectedListener<CategoryListModel.CategoryListData>? =
            null
        private val spinnerItems: MutableList<CategoryListModel.CategoryListData> = arrayListOf()

        override fun onBindViewHolder(holder: ViewHolder, position: Int) {
            val model = spinnerItems[holder.adapterPosition]
            holder.itemView.tvItem.setText(model.categoryName)
            holder.itemView.setOnClickListener {
                notifyItemSelected(position)
            }
        }

        // we must call the spinnerView.notifyItemSelected method to let PowerSpinnerView know about changed information.
        override fun notifyItemSelected(index: Int) {
            this.spinnerView.notifyItemSelected(index, spinnerItems[index].categoryName)
            this.onSpinnerItemSelectedListener?.onItemSelected(index, spinnerItems[index])
        }

        override fun onCreateViewHolder(
            parent: ViewGroup,
            viewType: Int
        ): ViewHolder {
            var mInflater: LayoutInflater = context!!.getSystemService(Activity.LAYOUT_INFLATER_SERVICE) as LayoutInflater

            val v =
                mInflater.inflate(R.layout.raw_category_list, parent, false)
            return ViewHolder(
                v
            )
        }

        override fun getItemCount(): Int {
            return this.spinnerItems.size
        }

        override fun setItems(itemList: List<CategoryListModel.CategoryListData>) {
            this.spinnerItems.clear()
            this.spinnerItems.addAll(itemList)
            notifyDataSetChanged()
        }

        inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)
    }

@skydoves please correct me if anything is wrong