在OnBindViewHolder RecyclerView的{{1}}里面，我有多个物品。其中的一个（ITEM_TRATAMENTOS）得到了一个setOnClickListener，目的是当我单击按钮（add_field_btn）时创建一个Adapter。问题在于LinearLayout的唯一参数尚未解析（ Context.LAYOUT_INFLATER_SERVICE ）。
在getSystemService中它可以正常工作，但在OnBindViewHolder中却并非如此。
ViewPagers预期结果是创建新行，如果它在正常活动中，它将起作用。
答案 0 :(得分：0)
步骤1：将apply参数添加到import numpy as np
import pandas as np
df = pd.DataFrame()
df['a'] = np.zeros(10) # or get data from somewhere else
p = 2/7
df.a.apply(lambda x: np.nan if np.random.rand() < p else np.random.rand())
子类的构造函数中。
步骤2：创建LayoutInflater时，请传递您从RecyclerView.Adapter获得的RecyclerView.Adapter上的活动信息。
例如，这是一个名为LayoutInflater的{{1}}：
getLayoutInflater()请注意，我的RecyclerView.Adapter构造函数将ColorAdapter作为参数。
以下是使用该/*
Copyright (c) 2018 CommonsWare, LLC
Licensed under the Apache License, Version 2.0 (the "License"); you may not
use this file except in compliance with the License. You may obtain a copy
of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required
by applicable law or agreed to in writing, software distributed under the
License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
OF ANY KIND, either express or implied. See the License for the specific
language governing permissions and limitations under the License.
Covered in detail in the book _Elements of Android Jetpack_
https://commonsware.com/Jetpack
*/
package com.commonsware.jetpack.sampler.recyclerview
import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.ListAdapter
class ColorAdapter(private val inflater: LayoutInflater) :
ListAdapter<Int, ColorViewHolder>(ColorDiffer) {
override fun onCreateViewHolder(
parent: ViewGroup,
viewType: Int
): ColorViewHolder {
return ColorViewHolder(inflater.inflate(R.layout.row, parent, false))
}
override fun onBindViewHolder(holder: ColorViewHolder, position: Int) {
holder.bindTo(getItem(position))
}
private object ColorDiffer : DiffUtil.ItemCallback<Int>() {
override fun areItemsTheSame(oldColor: Int, newColor: Int): Boolean {
return oldColor == newColor
}
override fun areContentsTheSame(oldColor: Int, newColor: Int): Boolean {
return areItemsTheSame(oldColor, newColor)
}
}
}
的活动：
ColorAdapter由于您和我都在用Kotlin写作，因此private val inflater: LayoutInflater调用变成了对活动上ColorAdapter属性的引用。因此，在创建/*
Copyright (c) 2018 CommonsWare, LLC
Licensed under the Apache License, Version 2.0 (the "License"); you may not
use this file except in compliance with the License. You may obtain a copy
of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required
by applicable law or agreed to in writing, software distributed under the
License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
OF ANY KIND, either express or implied. See the License for the specific
language governing permissions and limitations under the License.
Covered in detail in the book _Elements of Android Jetpack_
https://commonsware.com/Jetpack
*/
package com.commonsware.jetpack.sampler.recyclerview
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.DividerItemDecoration
import androidx.recyclerview.widget.LinearLayoutManager
import kotlinx.android.synthetic.main.activity_main.*
import java.util.*
class MainActivity : AppCompatActivity() {
private val random = Random()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
items.apply {
layoutManager = LinearLayoutManager(this@MainActivity)
addItemDecoration(
DividerItemDecoration(this@MainActivity, DividerItemDecoration.HORIZONTAL)
)
adapter = ColorAdapter(layoutInflater).apply {
submitList(buildItems())
}
}
}
private fun buildItems() = generateSequence { random.nextInt() }
.take(25)
.toList()
}
时，我使用getLayoutInflater()来传递layoutInflater的实例。
答案 1 :(得分：0)
另一种解决方案是从LayoutInflater ViewGroup获取parentLinearLayout。
示例
parentLinearLayout?.apply {
val inflater = LayoutInflater.from(context) // context is now available in the receiver scope
val rowView = inflater.inflate(R.layout.used_products_field, this, false)
addView(rowView) // Add the view to the last position
}
此外，请注意添加过多视图而不回收视图的后果。如果数量足够大，可能还需要另一个RecyclerView。