Create Virtual RowView WPF | Saatody | Amit Padhiyar

XAML

<Window x:Class="WpfApp23.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp23"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="3*"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <ScrollViewer Grid.Column="0" Grid.Row="0" Name="LeftScroll">
            <StackPanel>
                <Grid Name="Left"></Grid>
            </StackPanel>
        </ScrollViewer>
        <Grid Grid.Column="1" Grid.Row="0">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="20"/>
            </Grid.ColumnDefinitions>

            <StackPanel Name="Right" Grid.Column="0"/>
            <ScrollBar Name="RightScroll" Grid.Column="1"/>
        </Grid>
        <Grid Grid.Column="0" Grid.Row="1">
            <Button Content="Add Row" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top" Width="75"/>
            <TextBox HorizontalAlignment="Left" Height="23" Margin="10,72,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="75"/>
            <Button Content="Set Height" HorizontalAlignment="Left" Margin="90,72,0,0" VerticalAlignment="Top" Width="75"/>

        </Grid>
        <Grid Grid.Column="1" Grid.Row="1">
            <Button Content="Add Row" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top" Width="75"/>
            <TextBox Name="IndexOf" HorizontalAlignment="Left" Height="23" Margin="10,72,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="75"/>
            <TextBox Name="Height" HorizontalAlignment="Left" Height="23" Margin="90,72,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="75"/>
            <Button Name="SetHeight" Content="Set Height" HorizontalAlignment="Left" Margin="170,72,0,0" VerticalAlignment="Top" Width="75"/>

        </Grid>
    </Grid>
</Window>

C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApp23
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private List<Row> Rows = new List<Row>();
        private Rows rows = new Rows();
        public MainWindow()
        {
            InitializeComponent();
            Rows = rows.CreateRows(1);
            System.Console.WriteLine("Rows.Count: " + Rows.Count);

            RightScroll.Minimum = 0;
            RightScroll.Maximum = rows.TotalHeight;
            RightScroll.SmallChange = 10;
            RightScroll.LargeChange = 30;
            Event();
        }
        
        private double Top = 0.0;
        private int StartRow = 0;
        private int EndRow = 0;
        private void Event()
        {
            RightScroll.Scroll += (sender, e) => {
                try
                {
                    System.Console.WriteLine(RightScroll.Value);
                    System.Console.WriteLine(RightScroll.Minimum);
                    System.Console.WriteLine(RightScroll.Maximum);
                    System.Console.WriteLine(RightScroll.SmallChange);
                    System.Console.WriteLine(RightScroll.LargeChange);

                    Top = 0.0;
                    StartRow = 0;
                    EndRow = 0;

                    double Value = RightScroll.Value;
                    double TotalHeight = 0.0;
                    int Index = 0;

                    while(TotalHeight <= Value)
                    {
                        if (Rows.Count > Index)
                        {
                            TotalHeight += Rows[Index].Height;
                            Index++;
                        }
                        else
                        {
                            break;
                        }
                    }
                    Index -= 1;
                    StartRow = Index;
                    Top = -(Rows[StartRow].Height - (TotalHeight - Value));

                    TotalHeight = TotalHeight - Value;
                    while (TotalHeight <= Right.ActualHeight)
                    {
                        if (Rows.Count > Index)
                        {
                            TotalHeight += Rows[Index].Height;
                            Index++;
                        }
                        else
                        {
                            break;
                        }
                    }
                    // One More Time
                    if (Rows.Count > Index)
                    {
                        TotalHeight += Rows[Index].Height;
                        Index++;
                    }
                    EndRow = Index - 1;

                    System.Console.WriteLine("Top: " + Top);
                    System.Console.WriteLine("Value: " + RightScroll.Value);
                    System.Console.WriteLine("StartRow: " + StartRow);
                    System.Console.WriteLine("EndRow: " + EndRow);

                    Right.Children.Clear();
                    for (int i = StartRow; i <= EndRow; i++)
                    {
                        if(i != StartRow)
                        {
                            Top = 0;
                        }
                        RowModel Model = new RowModel();
                        Model.Row = Rows[i];
                        Model.Index = Rows[i].Index;
                        Model.Text = Rows[i].Text;
                        Model.Margin = new Thickness(0, Top, 0, 0);
                        Model.Width = Rows[i].Width;
                        Model.Height = Rows[i].Height;
                        Model.Background = new SolidColorBrush(Rows[i].Color);
                        Right.Children.Add(Model);

                        Top += Rows[i].Height;
                    }
                }
                catch(Exception Ex) {
                    System.Console.WriteLine("Exception: " + Ex);
                }
            };
            SetHeight.Click += (sender, e) =>
            {
                int i = Int32.Parse(IndexOf.Text);
                double d = Double.Parse(Height.Text);
                Rows[i].Height = d;

                double Total = 0.0;
                for(int loop=0; loop<Rows.Count; loop++)
                {
                    Total += Rows[loop].Height;
                }

                rows.TotalHeight = Total;
                RightScroll.Maximum = rows.TotalHeight;
            };
        }
    }

    public class Row
    {
        public int Index { set; get; }
        public string Text { set; get; }
        public double Width { set; get; }
        public double Height { set; get; }
        public Color Color { set; get; }
    }
    public class Rows
    {
        private List<Row> rows = new List<Row>();
        public double TotalHeight = 0.0;
        public List<Row> CreateRows(int n)
        {
            for (int i = 0; i < n; i++)
            {
                Row Row = new Row();
                Row.Index = i;
                Row.Text = "Text-" + i;
                Row.Width = 1000;
                Row.Height = 100;
                TotalHeight += 100;
                if (i % 2 == 0)
                {
                    Row.Color = Color.FromRgb(20, 20, 20);
                }
                else
                {
                    Row.Color = Color.FromRgb(40, 40, 40);
                }

                rows.Add(Row);
            }

            return rows;
        }
    }
    public class RowModel : Grid
    {
        public Row Row { set; get; }
        public int Index { set; get; }
        private string text;
        public string Text
        {
            set
            {
                text = value;
                TB.Text = text;
            }
            get
            {
                return Text;
            }
        }

        private TextBlock TB = new TextBlock();
        public RowModel()
        {
            this.HorizontalAlignment = HorizontalAlignment.Left;
            this.VerticalAlignment = VerticalAlignment.Top;

            TB.HorizontalAlignment = HorizontalAlignment.Left;
            TB.VerticalAlignment = VerticalAlignment.Top;
            TB.Margin = new Thickness(20, 20, 0, 0);
            TB.Width = 100;
            TB.Height = 25;
            TB.Foreground = new SolidColorBrush(Color.FromRgb(255, 255, 255));
            this.Children.Add(TB);
        }
    }

}

It is work properly with high memory management.