在列表中创建一个喜爱的复选框，Kotlin

Question

我希望为列表中的项目创建一个复选框。

我正在考虑通过为我的项目使用布尔值来应用这一点，即如果属性' favorite ' = true，则复选框突出显示，反之亦然，如果为false。

不幸的是，到目前为止，我不确定这个逻辑以及如何将它连接到我的视图(复选框)。

我的观点如下:

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView
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="wrap_content"
android:layout_marginBottom="8dp"
android:elevation="24dp">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/relativeLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp">
<ImageView
android:id="@+id/imageIcon"
android:layout_width="64dp"
android:layout_height="64dp"
android:layout_marginTop="4dp"
android:layout_marginEnd="16dp"
android:contentDescription="@string/change_hike_image"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/hikeName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:textAlignment="viewStart"
android:textSize="30sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.048"
app:layout_constraintStart_toEndOf="@+id/imageIcon"
app:layout_constraintTop_toTopOf="parent"
tools:text="A Title" />
<TextView
android:id="@+id/description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:textAlignment="viewStart"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.052"
app:layout_constraintStart_toEndOf="@+id/imageIcon"
app:layout_constraintTop_toBottomOf="@id/hikeName"
tools:text="A Description" />
<CheckBox
android:id="@+id/favourite"
style="?android:attr/starStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.cardview.widget.CardView>

适配器:

package org.wit.hikingtrails.adapters
import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.squareup.picasso.Picasso
import org.wit.hikingtrails.databinding.CardHikeBinding
import org.wit.hikingtrails.models.HikeModel
interface HikeListener {
fun onHikeClick(hike: HikeModel)
}
class HikeAdapter constructor(private var hikes: List<HikeModel>,
private val listener: HikeListener) :
RecyclerView.Adapter<HikeAdapter.MainHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MainHolder {
val binding = CardHikeBinding
.inflate(LayoutInflater.from(parent.context), parent, false)
return MainHolder(binding)
}
override fun onBindViewHolder(holder: MainHolder, position: Int) {
val hike = hikes[holder.adapterPosition]
holder.bind(hike, listener)
}
override fun getItemCount(): Int = hikes.size
class MainHolder(private val binding : CardHikeBinding) :
RecyclerView.ViewHolder(binding.root) {
fun bind(hike: HikeModel, listener: HikeListener) {
binding.hikeName.text = hike.name
binding.description.text = hike.description
binding.favourite.text = hike.favourite.toString()
if (hike.image != ""){
Picasso.get()
.load(hike.image)
.resize(200, 200)
.into(binding.imageIcon)
}
binding.root.setOnClickListener { listener.onHikeClick(hike) }
}
}
}

视图:

package org.wit.hikingtrails.views.hikeList
import android.os.Bundle
import android.view.Menu
import android.view.MenuItem
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.LinearLayoutManager
import org.wit.hikingtrails.R
import org.wit.hikingtrails.adapters.HikeAdapter
import org.wit.hikingtrails.adapters.HikeListener
//import org.wit.hikingtrails.databinding.ActivityHikeListBinding
import org.wit.hikingtrails.main.MainApp
import org.wit.hikingtrails.models.HikeModel
import android.content.Intent
import android.view.*
import androidx.recyclerview.widget.RecyclerView
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.launch
import org.wit.hikingtrails.databinding.ActivityHikeListBinding
import org.wit.hikingtrails.views.BaseView
import timber.log.Timber
class HikeListView :  BaseView(), HikeListener {
lateinit var app: MainApp
lateinit var binding: ActivityHikeListBinding
lateinit var presenter: HikeListPresenter
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityHikeListBinding.inflate(layoutInflater)
setContentView(binding.root)
binding.toolbar.title = title
setSupportActionBar(binding.toolbar)
presenter = HikeListPresenter(this)
val layoutManager = LinearLayoutManager(this)
binding.recyclerView.layoutManager = layoutManager
updateRecyclerView()
}
//    override fun showHikes(hikes: List<HikeModel>) {
//        recyclerView.adapter = HikeAdapter(hikes, this)
//        recyclerView.adapter?.notifyDataSetChanged()
//    }
override fun onCreateOptionsMenu(menu: Menu): Boolean {
menuInflater.inflate(R.menu.menu_main, menu)
return super.onCreateOptionsMenu(menu)
}
override fun onResume() {
//update the view
super.onResume()
updateRecyclerView()
binding.recyclerView.adapter?.notifyDataSetChanged()
Timber.i("recyclerView onResume")
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
when (item?.itemId) {
R.id.item_add -> presenter.doAddHike()
R.id.item_map -> presenter.doShowHikesMap()
R.id.logout -> presenter.doLogout()
}
return super.onOptionsItemSelected(item)
}
override fun onHikeClick(hike: HikeModel) {
presenter.doEditHike(hike)
}
private fun updateRecyclerView(){
GlobalScope.launch(Dispatchers.Main){
binding.recyclerView.adapter =
HikeAdapter(presenter.getHikes(), this@HikeListView)
}
}
}

Answer 1

为HikeModel添加favorite属性

data class HikeModel(
... code
// use mutable property bcs you will update it later when checkbox is checked or uncheck.
var favorite: Boolean = false // false by default
)

和

fun bind(hike: HikeModel, listener: HikeListener) {
...
binding.favourite.isChecked = hike.favorite
binding.favourite.setOnClickListener {
hike.favorite = binding.favourite.isChecked
listener.onHikeClick(hike)
}
...
}