IssueTracker

MainActivity
class MainActivity : AppCompatActivity() {
    val adapter = MyAdapter(this)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        findViewById<ViewPager2>(R.id.vp).adapter = adapter
    }

}

class MyAdapter(activity: MainActivity) : FragmentStateAdapter(activity) {

    override fun getItemCount(): Int {
      return 1
    }

    override fun createFragment(position: Int): Fragment {
        return MainFragment()
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="match_parent"
    tools:context=".MainActivity">

    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/vp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

MainFragment
package com.example.myapplication

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.core.view.isVisible
import androidx.databinding.DataBindingUtil
import androidx.databinding.ViewDataBinding
import androidx.fragment.app.Fragment
import com.example.myapplication.databinding.FragmentMainBinding

/**
 * @author sunshaobei on 2023/8/4
 */
class MainFragment:Fragment() {

    lateinit var dataBinding: FragmentMainBinding
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        dataBinding = DataBindingUtil.inflate(inflater,R.layout.fragment_main,container,false)
        dataBinding.testBtn.setOnClickListener {
            dataBinding.cl.isVisible = !dataBinding.cl.isVisible
        }
        return dataBinding.root

    }
}

<?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>

    </data>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/cl"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:visibility="gone"
            android:layout_gravity="center">

            <View
                android:id="@+id/tv"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="#ff0000"
                android:gravity="center"
                android:paddingStart="6dp"
                android:textSize="13sp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />


        </androidx.constraintlayout.widget.ConstraintLayout>


        <Button
            android:id="@+id/test_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="show"
            android:text="显示"
            android:layout_gravity="center_horizontal|bottom" />

    </FrameLayout>
</layout>

run this and I found view can not show normal

and I replace the ConstraintLayout that needs to be dynamically displayed with another ViewGoup

<?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>

    </data>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
      
        <LinearLayout
            android:id="@+id/cl"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:visibility="gone"
            android:layout_gravity="center">

            <View
                android:id="@+id/tv"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="#ff0000"
                android:gravity="center"
                android:paddingStart="6dp"
                android:textSize="13sp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />


        </LinearLayout>


        <Button
            android:id="@+id/test_btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="show"
            android:text="显示"
            android:layout_gravity="center_horizontal|bottom" />

    </FrameLayout>
</layout>

I change the constraintlayout to linerlayout then the view can display normal

I have solved the problem by reading the source code

this is my solution

package com.example.myapplication

import android.content.Context
import android.util.AttributeSet
import android.view.View
import android.view.ViewGroup
import androidx.appcompat.widget.AppCompatTextView
import androidx.constraintlayout.widget.ConstraintLayout

/**
 * @author sunshaobei on 2023/8/3
 */
class CustomConstraintLayout: ConstraintLayout {

    constructor(context: Context) : super(context)
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(
        context, attrs, defStyleAttr
    )
    override fun addView(child: View?, params: ViewGroup.LayoutParams?) {
        checkResolve(child)
        super.addView(child, params)
    }

    fun checkResolve(child: View?):Boolean{
        return child?.paddingStart != null
    }

}

i use CustomConstraintLayout to replace ConstraintLayout