Android

<Frame BackgroundColor="Black"
                  CornerRadius="10"
                  HasShadow="False"
                  Opacity="0.5"
                  Margin="30">
       <FlexLayout Direction="Column"
               JustifyContent="SpaceEvenly"
               Padding="5">

           <StackLayout>
               <Label Text="قد شما چند سانتیمتر است؟"
                  Style="{StaticResource TitleStyle}"/>
               <Label Text="{Binding Source={x:Reference HeightSlider},
               Path=Value,
               StringFormat='{0:F0} cm'}"
                  Style="{StaticResource ValueStyle}"/>
               <Slider x:Name="HeightSlider"
                   Maximum="220"
                   Minimum="40"
                   Value="{Binding Height}"/>
           </StackLayout>
           <StackLayout>
               <Label Text="وزن شما چند کیلوگرم است؟"
                  Style="{StaticResource TitleStyle}"/>
               <Label Text="{Binding Source={x:Reference WeightSlider},
               Path=Value,
               StringFormat='{0:F0} kg'}"
                  Style="{StaticResource ValueStyle}"/>
               <Slider x:Name="WeightSlider"
                   Maximum="150"
                   Minimum="5"
                   Value="{Binding Weight}"/>
           </StackLayout>
           <StackLayout>
               <Label Text="شاخص توده بدنی شما:"
                  Style="{StaticResource LabelStyle}"/>
               <Label Text="{Binding BMI}"
                  Style="{StaticResource LabelStyle}"
                  FontSize="48"/>
               <Label Text="{Binding Classification}"
                  Style="{StaticResource LabelStyle}"
                  FontSize="20"/>
           </StackLayout>
       </FlexLayout>
   </Frame>

• OS Name: Microsoft Windows 10 Pro (64 bit OS)
• OS Version: 10.0.19042 Build 19042.906
• OS Experience: Windows Feature Experience Pack 120.2212.551.0
• Processor: AMD Phenom II X2 545 Processor, 3.00 GHz, 2 Cores (x64-based processor)
• Motherboard: ASUS M4A78LT-M-LE
• Motherboard Version: Rev X.0x
• RAM: 6.00 GB (5.75 GB usable)
• Hyper-V - VM Monitor Mode Extensions: Yes
• Hyper-V - Second Level Address Translation Extensions: Yes
• Hyper-V - Virtualization Enabled in Firmware: Yes
• Hyper-V - Data Execution Protection: Yes

Is it possible to write an application that takes the user coordinates and puts it in uber application

package com.ishidakorea.test02

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import java.lang.Exception

class MainActivity : AppCompatActivity(), A.interA, Child.interChild
{
    override fun Child_EventFire()
    {
        // Child Class Listener
    }
    override fun A_SendPost()
    {
        // AA Class Listener
    }

    override fun onCreate(savedInstanceState: Bundle?)
    {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        var A1 = A()

    }


}

class A : Child(), Child.interChild {

    interface interA
    {
        fun A_SendPost()
    }

    lateinit var LinstenerA : A.interA

    init {
        LinstenerA = this@A as A.interA // Exception
    }

    fun FireA()
    {
        if (LinstenerA != null)
            LinstenerA.A_SendPost()
    }
    
    override fun Child_EventFire()
    {

    }

    
}

open class Child {

    interface interChild
    {
        fun Child_EventFire()
    }

    lateinit var LinstenerB : interChild

    init {
            LinstenerB = this@Child as interChild // OK
    }

    fun Fire()
    {
        if (LinstenerB != null)
            LinstenerB.Child_EventFire()
    }



}

An error occurs while creating a new listener from a parent class that inherits a child class that has a listener.

Why is that?

If you know anyone, please advise.