带有 RecyclerView 的自定义对话框仅显示第一项

Question

在此输入图片描述

我正在尝试在 Android 应用程序中创建一个自定义对话框，该对话框使用 RecyclerView 显示列表。但是，当我运行该应用程序时，该对话框仅显示列表的第一项。我想显示列表中的所有项目。

如何显示所有列表

这是我的 MainActivity 、CustomDialog 和 MainDropdownAdapter 类的相关代码

class MainActivity : AppCompatActivity() {

    private lateinit var mainDropdownGroup: TextView


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)

        val binding: ActivityMainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main)

        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }

        mainDropdownGroup = findViewById(R.id.main_dropdown_group)


        val groups = arrayListOf(
            MainDropDownModel("Group A", " "),
            MainDropDownModel("Group B", "admin"),
            MainDropDownModel("Group C", " "),
            MainDropDownModel("Group D", " ")
        )

        mainDropdownGroup.setOnClickListener {
            CustomDialog(this, groups) { selectedItem ->
                mainDropdownGroup.text = selectedItem.device_title 
            }.show()
        }

    }

}

class CustomDialog(
    context: Context,
    private val dataList: ArrayList<MainDropDownModel>,
    private val onItemSelected: (MainDropDownModel) -> Unit
) : Dialog(context) {

    private lateinit var recyclerView: RecyclerView
    private lateinit var dropdownAdapter: MainDropdownAdapter

    init {
        val view = LayoutInflater.from(context).inflate(R.layout.item_dropdown_list, null)
        setContentView(view)


        recyclerView = view.findViewById(R.id.dialog_RV)
        recyclerView.layoutManager = LinearLayoutManager(context)

        window?.setBackgroundDrawableResource(android.R.color.transparent)

        dropdownAdapter = MainDropdownAdapter(context, dataList)
        recyclerView.adapter = dropdownAdapter

        dropdownAdapter.setOnItemClickListener { item ->
            onItemSelected(item)
            dismiss()
        }

        val params = window?.attributes
        params?.width = context.resources.displayMetrics.widthPixels - 30.dpToPx(context)
        params?.height = WindowManager.LayoutParams.WRAP_CONTENT
        window?.attributes = params
    }

    fun Int.dpToPx(context: Context): Int {
        return (this * context.resources.displayMetrics.density).toInt()
    }
}

class MainDropdownAdapter(
    private val context: Context,
    private val dropdownList: ArrayList<MainDropDownModel>
) : RecyclerView.Adapter<MainDropdownAdapter.ViewHolder>() {

    private var onItemClickListener: ((MainDropDownModel) -> Unit)? = null

    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val itemName: TextView = itemView.findViewById(R.id.dropdown_item_text)
        val itemImg: TextView = itemView.findViewById(R.id.dropdown_item_img)

        fun bindItems(item: MainDropDownModel) {
            itemName.text = item.device_title
            itemImg.text = item.device_choice
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(context).inflate(R.layout.item_dropdown, parent, false)
        return ViewHolder(view)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val currentItem = dropdownList[position]
        holder.bindItems(currentItem)

        holder.itemView.setOnClickListener {
            onItemClickListener?.invoke(currentItem)
        }
    }

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

    fun setOnItemClickListener(listener: (MainDropDownModel) -> Unit) {
        onItemClickListener = listener
    }
}

当我单击 mainDropdownGroup TextView 时，会出现该对话框，但它仅显示组列表中的第一项。我希望看到对话框中列出的所有项目，但只显示第一个。

Answer 1

尝试将item_dropdown_list主布局高度match_parent更改为wrap_content。它将占据 RecyclerView 的整个高度。

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <!-- item views -->
</LinearLayout>