How to create an android Bottom sheet that fits the size of the sheet with view always aligned to bo-CodePudding

The

CodePudding user response：

You can make the buttons layout to always be displayed at the bottom of the sheet by setting its y coordinate by tracking the bottom sheet sliding using addBottomSheetCallback callbacks:

val bottomSheet = findViewById<ConstraintLayout>(R.id.bottom_sheet) val bottomLayout = findViewById<LinearLayout>(R.id.button_layout) // initial setting the y coordinates of the bottom layout bottomSheet.post { val bottomSheetVisibleHeight = bottomSheet.height - bottomSheet.top bottomLayout.y = (bottomSheetVisibleHeight - bottomLayout.height).toFloat() } BottomSheetBehavior.from(bottomSheet).apply { addBottomSheetCallback(object : BottomSheetBehavior.BottomSheetCallback() { override fun onSlide(bottomSheet: View, slideOffset: Float) { // set the y coordinates of the bottom layout on bottom sheet slide val bottomSheetVisibleHeight = bottomSheet.height - bottomSheet.top bottomLayout.y = (bottomSheetVisibleHeight - bottomLayout.height).toFloat() } override fun onStateChanged(bottomSheet: View, newState: Int) { } }) }

Layout:

<?xml version="1.0" encoding="utf-8"?> <androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent">  <androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent"> </androidx.constraintlayout.widget.ConstraintLayout> <androidx.coordinatorlayout.widget.CoordinatorLayout android:layout_width="match_parent" android:layout_height="match_parent"> <androidx.constraintlayout.widget.ConstraintLayout android:id="@ id/bottom_sheet" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" app:behavior_hideable="false" app:layout_behavior="@string/bottom_sheet_behavior"> <androidx.recyclerview.widget.RecyclerView android:id="@ id/recyclerview" android:layout_width="0dp" android:layout_height="0dp" android:background="#CFE2F3" app:layout_constraintBottom_toTopOf="@ id/button_layout" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <LinearLayout android:id="@ id/button_layout" android:layout_width="match_parent" android:layout_height="60dp" android:background="#FF03DAC5" android:orientation="horizontal" app:layout_constraintBottom_toBottomOf="parent"> <Button android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginStart="8dp" android:layout_marginEnd="40dp" android:layout_weight="1" android:text="cancel" /> <Button android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginEnd="8dp" android:layout_weight="1" android:text="ok" /> </LinearLayout> </androidx.constraintlayout.widget.ConstraintLayout> </androidx.coordinatorlayout.widget.CoordinatorLayout> </androidx.coordinatorlayout.widget.CoordinatorLayout>