How can i set layoutmanager to RecycleView using kotlin

You can try using below solution

val mRecyclerView= v.findViewById<RecyclerView>(R.id.rec) //id RecyclerView
mRecyclerView.layoutManager = LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL,false)

use RecyclerView.HORIZONTAL for AndroidX instead of LinearLayoutManager.HORIZONTAL


var vegetableList: RecyclerView = findViewById(R.id.list_vegetable)
vegetableList.layoutManager = LinearLayoutManager(this,
RecyclerView.HORIZONTAL, false)

Choose the layout:

- LinearLayoutManager(context). // vertical
- LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false) // horizontal
- GridLayoutManager(context, numberOfColumns) // grid


Then apply the layout using Kotlin's apply() which removes repetition.

val rv = view.findViewById(R.id.recyclerView) as RecyclerView
rv.apply {
layoutManager = LinearLayoutManager(context)
adapter = recyclerViewAdapter()
setHasFixedSize(true)
...
}

It can also be set in XML like this:

app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"

For more info see: [here][1] and [here][2].


[1]:

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[2]:

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If you are working with Kotlin android.

Declare lateinit variable smoothScroller

lateinit var smoothScroller: SmoothScroller

Within OnCreate Mehtod Initilize the smoothScroller

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
smoothScroller = object : LinearSmoothScroller(context) {
override fun getVerticalSnapPreference(): Int {
return SNAP_TO_START
}
}
}

Finally, Check if the Adopter is Initialized or not?
Commit Old dataset changes if there are any.
Set the position.
Start scroller.

if (this@ChooseTemplate::genericAdapter.isInitialized && this@ChooseTemplate::smoothScroller.isInitialized) {
[email protected]!!.notifyDataSetChanged()
smoothScroller.setTargetPosition([email protected]);
dataBinding!!.rvTemplate.layoutManager!!.startSmoothScroll([email protected]);
}

dataBinding is an binding object.
rvTemplate is a Recycler View.
genericadapter is an adopter for rvTemplate.
templatesrowIndex is the index to check which row item is currently selected.

**Handling Errors while Creating a layoutManager with recyclerView in mainActivity.kt**

-> Add `android:id="@+id/recyclerView"`

-> In build.gradle(Module :app) add this line `id 'kotlin-android-extensions` under plugin then click on Sync Now

-> add below line in MainActivity.kt

val recyclerView = findViewById<RecyclerView>(R.id.recyclerView)
recyclerView.layoutManager = LinearLayoutManager(this)