安卓学习过程中，系统为RecyclerView创建的Adapter只支持一种item。但是某些列表我需要多种，例如下面微信的设置页：
除了隐私这种标题，里面的Item还有两种。
- “账号于安全”，不带下划线且下方有灰色隔离块。
- “青少年模式”，带有灰色下划线。
接下来就使用多种Item实现这种效果。
代码实现
创建List
创建完成后会多出下面几个文件
创建Item（iOS中称为 Cell）
layout_test_item_one
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout_test_item_one"
android:layout_width="match_parent"
android:layout_height="60dp"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:background="@color/systemWhite"
android:layout_height="60dp">
<TextView
android:id="@+id/me_cell_setting_title"
android:layout_width="wrap_content"
android:layout_height="20dp"
android:text="账号于安全"
android:lines="1"
android:textColor="@color/titleColor"
android:textSize="16sp"
android:layout_marginStart="18dp"
android:minWidth="60dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:layout_width="16dp"
android:layout_height="16dp"
android:layout_marginEnd="6dp"
android:background="@drawable/ic_right_arrow"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
/>
<TextView
android:layout_width="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginStart="18dp"
app:layout_constraintStart_toStartOf="parent"
android:background="@color/dividerColor"
app:layout_constraintEnd_toEndOf="parent"
android:layout_height="1dp"/>
</androidx.constraintlayout.widget.ConstraintLayout>
</LinearLayout>
ItemTwo
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout_test_item_two"
android:layout_width="match_parent"
android:layout_height="69dp"
android:background="@color/navigationBarBackgroundColor"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:background="@color/systemWhite"
android:layout_height="60dp">
<TextView
android:id="@+id/me_cell_setting_title"
android:layout_width="wrap_content"
android:layout_height="20dp"
android:text="账号于安全"
android:lines="1"
android:textColor="@color/titleColor"
android:textSize="16sp"
android:layout_marginStart="18dp"
android:minWidth="60dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:layout_width="16dp"
android:layout_height="16dp"
android:layout_marginEnd="6dp"
android:background="@drawable/ic_right_arrow"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
</LinearLayout>
把新建的两个Item引入到 TestItemRecyclerViewAdapter
1.首先
修改为
2.然后在 TestItemRecyclerViewAdapter 类里面 创建Item
inner class ViewHolderOne(itemView: View) : RecyclerView.ViewHolder(itemView) {
var rv_1: LinearLayout = itemView.findViewById(R.id.layout_test_item_one)
var titleText = rv_1.findViewById<TextView>(R.id.me_cell_setting_title)
}
inner class ViewHolderTwo(itemView: View) : RecyclerView.ViewHolder(itemView) {
var rv_2: LinearLayout = itemView.findViewById(R.id.layout_test_item_two)
var titleText = rv_2.findViewById<TextView>(R.id.me_cell_setting_title)
}
3.创建一个枚举管理Item
enum class ItemType(value:Int) {
ONE(0),
TWO(1)
}
4.通过枚举对item进行分类处理。
把values:List< PlaceholderItem>
然后 onCreateViewHolder onBindViewHolder 内部
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
when(viewType){
ItemType.ONE.ordinal -> {
val view: View =
LayoutInflater.from(parent.context)
.inflate(
R.layout.layout_test_item_one,
parent,
false
)
return ViewHolderOne(view)
}
ItemType.TWO.ordinal -> {
val view: View =
LayoutInflater.from(parent.context)
.inflate(
R.layout.layout_test_item_two,
parent,
false
)
return ViewHolderTwo(view)
}
else -> {
val view: View =
LayoutInflater.from(parent.context)
.inflate(
R.layout.layout_test_item_one,
parent,
false
)
return ViewHolderOne(view)
}
}
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
val item = values[position]
when(holder.itemViewType){
ItemType.ONE.ordinal -> {
var view : TestItemRecyclerViewAdapter.ViewHolderOne = holder as TestItemRecyclerViewAdapter.ViewHolderOne
view.titleText.text = item
}
ItemType.TWO.ordinal -> {
var view : TestItemRecyclerViewAdapter.ViewHolderTwo = holder as TestItemRecyclerViewAdapter.ViewHolderTwo
view.titleText.text = item
}
}
}
到这里 TestItemRecyclerViewAdapter 文件就搞定了。
Fragment里
新建两个数组
val titleArray : List<String> = listOf(
"账户于安全",
"青少年模式", "关怀模式",
"消息通知","设备", "通用",
"朋友权限", "设备信息于权限","个人信息收集清单", "第三方信息共享清单",
"帮助与反馈", "关于微信",
"插件",
"切换账号",
"退出微信")
var viewTypes = arrayOf(
ItemType.ONE,
ItemType.ONE, ItemType.TWO,
ItemType.ONE, ItemType.ONE, ItemType.TWO,
ItemType.ONE, ItemType.ONE, ItemType.ONE, ItemType.TWO,
ItemType.ONE, ItemType.TWO,
ItemType.TWO,
ItemType.TWO,
ItemType.TWO
)
adapter = TestItemRecyclerViewAdapter(titleArray, viewTypes)
然后代码编译：
