Android RecyclerView跳转新Activity时Intent传值失败问题解决

传值失败是两个代码逻辑错误导致的：

• 列表项点击事件里给Intent传入的所有参数都是getItemId(position)的返回值，该方法重写后返回的是列表位置的Long类型数字，根本不是商品标题、编码、价格这类实际业务数据
• 目标Activity里用getStringExtra()读取Long类型参数，数据类型完全不匹配，自然无法获取有效值
  另外代码还存在冗余导入、列表刷新通知位置计算越界的小问题，可一并修正。

1. 适配器ItemViewAdapter.kt修正 #

删除无用的java.security.AccessController.getContext导入，修正点击传参逻辑，推荐直接序列化传递整个商品对象，避免逐个写字段出错，同时修复分页插入的通知逻辑：

package com.example.app.adapter

import android.content.Context
import android.content.Intent
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.example.app.R
import com.example.app.models.products.Results
import com.example.app.ui.home.DescriptionActivity
import java.io.Serializable

// 注意：给你的Results数据类加上Serializable接口实现，格式示例：data class Results(xxx字段): Serializable
class ItemViewAdapter(private val context: Context) :
    RecyclerView.Adapter<ItemViewAdapter.MyViewHolder>() {

    private var itemList: MutableList<Results> = mutableListOf()
    private var page: Int = 0

    fun setListItem(item: List<Results>) {
        val oldSize = itemList.size
        itemList.addAll(item)
        // 修复原notify位置计算错误，避免数组越界
        notifyItemRangeInserted(oldSize, item.size)
        page++
    }

    class MyViewHolder(view: android.view.View) : RecyclerView.ViewHolder(view) {

        private val title = view.findViewById<TextView>(R.id.tvTitle)
        private val code = view.findViewById<TextView>(R.id.tvNumber)
        private val quantity = view.findViewById<TextView>(R.id.tvQuantity)
        private val price = view.findViewById<TextView>(R.id.tvPrice)
        private val available = view.findViewById<TextView>(R.id.tvAvailable)
        private val category = view.findViewById<TextView>(R.id.tvCategory)

        fun bind(item: Results) {
            title.text = item.name
            code.text = item.code.toString()
            quantity.text = item.quantities[0].quantity.toString()
            price.text = item.prices[0].price.toString()
            available.text = item.active.toString()
            category.text = item.category?.name
        }
    }

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

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

    override fun getItemId(position: Int): Long {
        return position.toLong()
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        val data = itemList[position]
        holder.bind(data)
        holder.itemView.setOnClickListener {
            val intent = Intent(context, DescriptionActivity::class.java)
            // 直接传递整个商品对象，无需逐个拼接字段，降低写错概率
            intent.putExtra("product_data", data)
            context.startActivity(intent)
        }
    }
}

2. 目标Activity DescriptionActivity.kt修正 #

直接读取传递过来的完整商品对象赋值，无需逐个读取零散字段：

package com.example.app.ui.home

import android.graphics.Color
import android.os.Build
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.view.WindowInsetsController
import android.view.WindowManager
import com.example.app.R
import com.example.app.databinding.ActivityDescriptionBinding
import com.example.app.models.products.Results

@Suppress("DEPRECATION")
class DescriptionActivity : AppCompatActivity() {

    private lateinit var binding: ActivityDescriptionBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        window.apply {
            clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS)
            addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS)
            decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
            statusBarColor = Color.TRANSPARENT
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
                    this@DescriptionActivity.window.decorView.windowInsetsController
                        ?.setSystemBarsAppearance(
                            0,
                            WindowInsetsController.APPEARANCE_LIGHT_STATUS_BARS
                        )
                }
            }
        }
        super.onCreate(savedInstanceState)
        binding = ActivityDescriptionBinding.inflate(layoutInflater)
        val view = binding.root
        setContentView(view)
        getItemIntent()

    }

    private fun getItemIntent(){
        // 兼容不同Android版本读取序列化对象
        val product = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
            intent.getSerializableExtra("product_data", Results::class.java)
        } else {
            @Suppress("DEPRECATION")
            intent.getSerializableExtra("product_data") as? Results
        }
        product?.let {
            setData(it)
        }
    }

    private fun setData(product: Results) {
        binding.tvTitle.text = product.name
        binding.tvCode.text = product.code.toString()
        binding.tvCategory.text = product.category?.name
        // 此处替换为你Results模型中实际的商品描述字段即可
        binding.tvDescription.text = product.description ?: ""
        binding.tvPrice.text = product.prices[0].price.toString()
        binding.tvQuantity.text = product.quantities[0].quantity.toString()
    }
}

• 列表跳转详情优先传递序列化后的完整数据模型，不要零散传递单个字段，减少参数名写错、类型不匹配的问题
• 如果商品模型字段非常多，不推荐直接用Intent序列化传参，可以只传递商品ID，进入详情页后再根据ID请求完整的商品详情接口，避免Intent传参大小超限
• RecyclerView分页加载调用notifyItemRangeInserted时，参数固定为「当前列表原有长度、本次新增数据条数」，不要手动计算分页偏移，避免出现数据越界、列表动画错乱问题

内容的提问来源于stack exchange，提问作者SaeedMoeen