按下按钮时，将项目动态添加到回收视图中

Question

我正在尝试构建一个布局，其中有一个回收视图，每个项目有三个水平对齐的编辑文本。我想在按下按钮时添加下一个项目。

这就是我试图构建的设计

这是回收器视图的适配器类

class AddProjectAdapter(private val itemsList : ArrayList<ItemDetails>) : RecyclerView.Adapter<AddProjectAdapter.AddProjectViewHolder>() {
inner class AddProjectViewHolder(private val binding : AddProjectItemViewBinding) : RecyclerView.ViewHolder(binding.root) {
fun bind(item : ItemDetails){
binding.item = item
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): AddProjectViewHolder{
return AddProjectViewHolder(AddProjectItemViewBinding.inflate(LayoutInflater.from(parent.context), parent, false))
}
override fun onBindViewHolder(holder: AddProjectViewHolder, position: Int) {
holder.bind(itemsList[position])
}
override fun getItemCount(): Int = itemsList.size
}

项的布局文件add_project_item_view.xml`

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<variable
name="item"
type="com.example.hero.models.ItemDetails" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.card.MaterialCardView
android:id="@+id/item_name_cardview"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:flow_horizontalBias="3"
app:cardBackgroundColor="@color/light_background"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="@id/g_v_1"
android:layout_marginRight="5dp">
<EditText
android:id="@+id/item_name_edittext"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Item Name"
android:text="@={item.itemName}"
android:textColor="@color/t_dark"
android:fontFamily="@font/metropolislight"
android:textSize="14dp"
android:textColorHint="@color/t_dark"
android:background="@null"
android:padding="10dp" />
</com.google.android.material.card.MaterialCardView>
<com.google.android.material.card.MaterialCardView
android:id="@+id/rate_unit_cardview"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:flow_horizontalBias="2"
android:layout_marginRight="5dp"
app:cardBackgroundColor="@color/light_background"
app:layout_constraintStart_toEndOf="@id/g_v_1"
app:layout_constraintEnd_toEndOf="@id/g_v_2">
<EditText
android:id="@+id/rate_unit_edittext"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Rate/Unit"
android:text="@={item.rate}"
android:textColorHint="@color/t_dark"
android:textColor="@color/t_dark"
android:fontFamily="@font/metropolislight"
android:textSize="14dp"
android:padding="10dp"
android:background="@null" />
</com.google.android.material.card.MaterialCardView>
<com.google.android.material.card.MaterialCardView
android:id="@+id/unit_cardview"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:flow_horizontalBias="2"
app:cardBackgroundColor="@color/light_background"
app:layout_constraintStart_toEndOf="@id/g_v_2"
app:layout_constraintEnd_toEndOf="parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/unit_textview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:background="@null"
android:fontFamily="@font/metropolislight"
android:hint="Unit"
android:padding="10dp"
android:text="@={item.unit}"
android:textColor="@color/t_dark"
android:textColorHint="@color/t_dark"
android:textSize="14dp" />
<ImageView
android:id="@+id/drop_down_imageview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:src="@drawable/dropdown"
android:layout_centerVertical="true" />
</RelativeLayout>
</com.google.android.material.card.MaterialCardView>
<androidx.constraintlayout.widget.Guideline
android:id="@+id/g_v_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.4" />
<androidx.constraintlayout.widget.Guideline
android:id="@+id/g_v_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.8" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>

`

//code of the activity in which the recycler view is present
private val itemsList : ArrayList<ItemDetails> = ArrayList()
private lateinit var addProjectAdapter: AddProjectAdapter
private lateinit var binding: ActivityAddProjectBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityAddProjectBinding.inflate(layoutInflater)
setContentView(binding.root)
setAdapter()
setListner()
}
private fun setAdapter(){
addProjectAdapter = AddProjectAdapter(itemsList)
binding.itemDetailsRecyclerview.apply {
layoutManager = LinearLayoutManager(this@AddProject)
adapter = addProjectAdapter
}
}
override fun onClick(v : View?) {
when(v?.id){
binding.addItemButton.id -> {
itemsList.add(ItemDetails())
addProjectAdapter.notifyItemInserted(itemsList.size-1)
}
}
}
private fun setListner(){
binding.addItemButton.setOnClickListener(this)
}

data class ItemDetails(
var itemName : String = "",
var rate : String = "",
var unit : String = "")

我的回收视图id是item_details_recyclerview。上述代码的输出

当我单击添加按钮时，添加的项目不可见，但添加按钮向下移动。有人能帮我解决这个问题吗？而且，如果你能提供一些更好的方法，那就太好了。提前谢谢。

Answer 1

从add_project_item_view.xml更改ConstraintLayout的高度

<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

到这个

<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">