【发布时间】:2020-10-02 14:51:22
【问题描述】:
我正在尝试创建一个包含 1 到 250 之间整数的回收器列表视图。
我遇到的问题是,当我滚动列表时,它只显示 1-9,然后随机只显示单个数字。是回收缓存的item值吗?
这是我的适配器的外观:
package com.work.me
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import kotlinx.android.synthetic.main.counter_layout.view.*
class CounterAdapter : RecyclerView.Adapter<CounterAdapter.ViewHolder>() {
private val counterList = mutableListOf<Int>()
init {
for (x in 0..COUNTER_MAX) {
Log.d("JJJ", "x is $x")
counterList.add(x + COUNTER_OFFSET)
}
}
inner class ViewHolder(private val view: View) : RecyclerView.ViewHolder(view) {
fun bindView(counterValue: String) {
Log.d("JJJ", "counterValue is $counterValue")
view.counterText.text = counterValue
Log.d("JJJ", " view.counterText is ${view.counterText.text}")
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val view = LayoutInflater.from(parent.context)
.inflate(R.layout.counter_layout, parent, false)
return ViewHolder(view)
}
override fun getItemCount(): Int {
Log.d("JJJ", "size is " + counterList.size)
return counterList.size
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bindView(counterList[position + COUNTER_OFFSET].toString())
}
override fun getItemId(position: Int): Long {
return position.toLong()
}
companion object {
const val COUNTER_MAX = 250
const val COUNTER_OFFSET = 1
}
}
如您所见,我已将日志放置在 bindView 函数上,传递的值是正确的,但从未显示在实际列表 ui 小部件上。
这是我使用适配器启动列表小部件的方式:
counterList.apply {
adapter = counterAdapter
// setHasFixedSize(true)
layoutManager = LinearLayoutManager(this@MainActivity)
}
这里是每个项目的柜台布局:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:id="@+id/counterText"
style="@style/TextAppearance.AppCompat.Headline" />
</androidx.constraintlayout.widget.ConstraintLayout>
活动布局
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
......
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/counterList"
android:layout_width="wrap_content"
android:layout_height="40dp"
android:layout_marginTop="20dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@id/counterButton" />
</androidx.constraintlayout.widget.ConstraintLayout>
提前致谢
【问题讨论】:
-
删除
override fun getItemId(),因为您没有更改稳定ID -
删除无效
标签: android android-layout android-recyclerview