Projektdateien hinzufügen.

WindowsFormsApp1.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.2.32616.157
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WindowsFormsApp1", "WindowsFormsApp1\WindowsFormsApp1.csproj", "{79AF4BD6-6931-4E8C-81D1-6464F70C480D}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{79AF4BD6-6931-4E8C-81D1-6464F70C480D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{79AF4BD6-6931-4E8C-81D1-6464F70C480D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{79AF4BD6-6931-4E8C-81D1-6464F70C480D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{79AF4BD6-6931-4E8C-81D1-6464F70C480D}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {A9D8D780-7933-4C17-A237-4CA5415FEBA1}
+	EndGlobalSection
+EndGlobal

WindowsFormsApp1/App.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
+    </startup>
+</configuration>

WindowsFormsApp1/ClassDiagram1.cd

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ClassDiagram MajorVersion="1" MinorVersion="1">
+  <Font Name="Segoe UI" Size="9" />
+</ClassDiagram>

WindowsFormsApp1/Form1.Designer.cs

@@ -0,0 +1,98 @@
+namespace WindowsFormsApp1
+{
+    partial class Form1
+    {
+        /// <summary>
+        /// Erforderliche Designervariable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Verwendete Ressourcen bereinigen.
+        /// </summary>
+        /// <param name="disposing">True, wenn verwaltete Ressourcen gelöscht werden sollen; andernfalls False.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Vom Windows Form-Designer generierter Code
+
+        /// <summary>
+        /// Erforderliche Methode für die Designerunterstützung.
+        /// Der Inhalt der Methode darf nicht mit dem Code-Editor geändert werden.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.button1 = new System.Windows.Forms.Button();
+            this.button2 = new System.Windows.Forms.Button();
+            this.extendedTB1 = new WindowsFormsApp1.Test.ExtendedTB();
+            this.baseTextBox1 = new WindowsFormsApp1.Test.BaseTextBox();
+            this.SuspendLayout();
+            // 
+            // button1
+            // 
+            this.button1.Location = new System.Drawing.Point(227, 125);
+            this.button1.Name = "button1";
+            this.button1.Size = new System.Drawing.Size(75, 23);
+            this.button1.TabIndex = 2;
+            this.button1.Text = "button1";
+            this.button1.UseVisualStyleBackColor = true;
+            this.button1.Click += new System.EventHandler(this.button1_Click);
+            // 
+            // button2
+            // 
+            this.button2.Location = new System.Drawing.Point(227, 200);
+            this.button2.Name = "button2";
+            this.button2.Size = new System.Drawing.Size(75, 27);
+            this.button2.TabIndex = 3;
+            this.button2.Text = "button2";
+            this.button2.UseVisualStyleBackColor = true;
+            this.button2.Click += new System.EventHandler(this.button2_Click);
+            // 
+            // extendedTB1
+            // 
+            this.extendedTB1.ForeColor = System.Drawing.Color.White;
+            this.extendedTB1.Location = new System.Drawing.Point(216, 174);
+            this.extendedTB1.Name = "extendedTB1";
+            this.extendedTB1.Size = new System.Drawing.Size(100, 20);
+            this.extendedTB1.TabIndex = 1;
+            // 
+            // baseTextBox1
+            // 
+            this.baseTextBox1.BackColor = System.Drawing.Color.DarkOrange;
+            this.baseTextBox1.Location = new System.Drawing.Point(216, 99);
+            this.baseTextBox1.Name = "baseTextBox1";
+            this.baseTextBox1.Size = new System.Drawing.Size(100, 20);
+            this.baseTextBox1.TabIndex = 0;
+            this.baseTextBox1.TextChanged += new System.EventHandler(this.baseTextBox1_TextChanged);
+            // 
+            // Form1
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(1222, 710);
+            this.Controls.Add(this.button2);
+            this.Controls.Add(this.button1);
+            this.Controls.Add(this.extendedTB1);
+            this.Controls.Add(this.baseTextBox1);
+            this.Name = "Form1";
+            this.Text = "Form1";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Test.BaseTextBox baseTextBox1;
+        private Test.ExtendedTB extendedTB1;
+        private System.Windows.Forms.Button button1;
+        private System.Windows.Forms.Button button2;
+    }
+}
+

WindowsFormsApp1/Form1.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using WindowsFormsApp1.OP;
+
+namespace WindowsFormsApp1
+{
+    public partial class Form1 : Form
+    {
+        Subject<string> Subject = new Subject<string>();
+
+        public Form1()
+        {
+            InitializeComponent();
+            Subject.Subscribe(new ClassObserver());
+            Subject.Subscribe(new PropertyObserver()); 
+        }
+
+        private void baseTextBox1_TextChanged(object sender, EventArgs e)
+        {
+            Subject.SetState(baseTextBox1.Text);
+        }
+
+        private void button1_Click(object sender, EventArgs e)
+        {
+            baseTextBox1.Reset();
+        }
+
+        private void button2_Click(object sender, EventArgs e)
+        {
+            extendedTB1.Reset();
+        }
+    }
+}

WindowsFormsApp1/Form1.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

WindowsFormsApp1/OP/ClassObserver.cs

@@ -0,0 +1,12 @@
+using System.Windows.Forms;
+
+namespace WindowsFormsApp1.OP
+{
+    public class ClassObserver: IObserver<int>
+    {
+        public void Update(ISubject<int> subject)
+        {
+            MessageBox.Show(subject.GetState().ToString());
+        }
+    }
+}

WindowsFormsApp1/OP/IObserver.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace WindowsFormsApp1.OP
+{
+    public interface IObserver<T>
+    {
+        /// <summary>
+        /// Receive update from subject
+        /// </summary>
+        void Update(ISubject<T> subject);
+    }
+}

WindowsFormsApp1/OP/ISubject.cs

@@ -0,0 +1,23 @@
+namespace WindowsFormsApp1.OP
+{
+    public interface ISubject<T>
+    {
+        /// <summary>
+        /// Attach an observer to the object.
+        /// </summary>
+        /// <param name="observer">Your Observer.</param>
+        void Subscribe(IObserver<T> observer);
+        /// <summary>
+        /// Detach an observer from an object.
+        /// </summary>
+        /// <param name="observer">Your observer.</param>
+        void Unsubscribe(IObserver<T> observer);
+        /// <summary>
+        /// Notify all observers about an event.
+        /// </summary>
+        void Notify();
+
+        void SetState(T state);
+        T GetState();
+    }
+}

WindowsFormsApp1/OP/PropertyObserver.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WindowsFormsApp1.OP
+{
+    public class PropertyObserver : IObserver<string>
+    {
+        public PropertyObserver()
+        { }
+
+        public void Update(ISubject<string> subject)
+        {
+            MessageBox.Show(subject.GetState());
+        }
+    }
+}

WindowsFormsApp1/OP/Subject.cs

@@ -0,0 +1,43 @@
+using System.Collections.Generic;
+
+namespace WindowsFormsApp1.OP
+{
+    /// <summary>
+    /// Owns some important state and notifies observers when the state changes.
+    /// </summary>
+    public class Subject<T> : ISubject<T>
+    { 
+        private protected List<IObserver<T>> _observers = null;
+        private object state { get;set; }
+
+        public Subject()
+        {
+            _observers = new List<IObserver<T>>();
+        }
+
+        public virtual void Subscribe(IObserver<T> observer)
+        {
+            _observers.Add(observer);
+        }
+        public virtual void Unsubscribe(IObserver<T> observer)
+        {
+            _observers.Remove(observer);
+        }
+        public void Notify()
+        {
+            foreach (IObserver<T> observer in _observers)
+            {
+                observer.Update(this);
+            }
+        }
+        public virtual void SetState(T state)
+        {
+            this.state = state;
+            Notify();
+        }
+        public virtual T GetState()
+        {
+            return (T)state;
+        }
+    }
+}

WindowsFormsApp1/Program.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WindowsFormsApp1
+{
+    internal static class Program
+    {
+        /// <summary>
+        /// Der Haupteinstiegspunkt für die Anwendung.
+        /// </summary>
+        [STAThread]
+        static void Main()
+        {
+            Application.EnableVisualStyles();
+            Application.SetCompatibleTextRenderingDefault(false);
+            Application.Run(new Form1());
+        }
+    }
+}

WindowsFormsApp1/Properties/AssemblyInfo.cs

@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// Allgemeine Informationen über eine Assembly werden über die folgenden
+// Attribute gesteuert. Ändern Sie diese Attributwerte, um die Informationen zu ändern,
+// die einer Assembly zugeordnet sind.
+[assembly: AssemblyTitle("WindowsFormsApp1")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("WindowsFormsApp1")]
+[assembly: AssemblyCopyright("Copyright ©  2022")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Durch Festlegen von ComVisible auf FALSE werden die Typen in dieser Assembly
+// für COM-Komponenten unsichtbar.  Wenn Sie auf einen Typ in dieser Assembly von
+// COM aus zugreifen müssen, sollten Sie das ComVisible-Attribut für diesen Typ auf "True" festlegen.
+[assembly: ComVisible(false)]
+
+// Die folgende GUID bestimmt die ID der Typbibliothek, wenn dieses Projekt für COM verfügbar gemacht wird
+[assembly: Guid("79af4bd6-6931-4e8c-81d1-6464f70c480d")]
+
+// Versionsinformationen für eine Assembly bestehen aus den folgenden vier Werten:
+//
+//      Hauptversion
+//      Nebenversion
+//      Buildnummer
+//      Revision
+//
+// Sie können alle Werte angeben oder Standardwerte für die Build- und Revisionsnummern verwenden,
+// indem Sie "*" wie unten gezeigt eingeben:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

WindowsFormsApp1/Properties/Resources.Designer.cs

@@ -0,0 +1,71 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     Dieser Code wurde von einem Tool generiert.
+//     Laufzeitversion: 4.0.30319.42000
+//
+//     Änderungen an dieser Datei können fehlerhaftes Verhalten verursachen und gehen verloren, wenn
+//     der Code neu generiert wird.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+namespace WindowsFormsApp1.Properties
+{
+
+
+    /// <summary>
+    ///   Eine stark typisierte Ressourcenklasse zum Suchen von lokalisierten Zeichenfolgen usw.
+    /// </summary>
+    // Diese Klasse wurde von der StronglyTypedResourceBuilder-Klasse
+    // über ein Tool wie ResGen oder Visual Studio automatisch generiert.
+    // Um einen Member hinzuzufügen oder zu entfernen, bearbeiten Sie die .ResX-Datei und führen dann ResGen
+    // mit der Option /str erneut aus, oder erstellen Sie Ihr VS-Projekt neu.
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "4.0.0.0")]
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
+    internal class Resources
+    {
+
+        private static global::System.Resources.ResourceManager resourceMan;
+
+        private static global::System.Globalization.CultureInfo resourceCulture;
+
+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
+        internal Resources()
+        {
+        }
+
+        /// <summary>
+        ///   Gibt die zwischengespeicherte ResourceManager-Instanz zurück, die von dieser Klasse verwendet wird.
+        /// </summary>
+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
+        internal static global::System.Resources.ResourceManager ResourceManager
+        {
+            get
+            {
+                if ((resourceMan == null))
+                {
+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("WindowsFormsApp1.Properties.Resources", typeof(Resources).Assembly);
+                    resourceMan = temp;
+                }
+                return resourceMan;
+            }
+        }
+
+        /// <summary>
+        ///   Überschreibt die CurrentUICulture-Eigenschaft des aktuellen Threads für alle
+        ///   Ressourcenlookups, die diese stark typisierte Ressourcenklasse verwenden.
+        /// </summary>
+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
+        internal static global::System.Globalization.CultureInfo Culture
+        {
+            get
+            {
+                return resourceCulture;
+            }
+            set
+            {
+                resourceCulture = value;
+            }
+        }
+    }
+}

WindowsFormsApp1/Properties/Resources.resx

@@ -0,0 +1,117 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

WindowsFormsApp1/Properties/Settings.Designer.cs

@@ -0,0 +1,30 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by a tool.
+//     Runtime Version:4.0.30319.42000
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+namespace WindowsFormsApp1.Properties
+{
+
+
+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "11.0.0.0")]
+    internal sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase
+    {
+
+        private static Settings defaultInstance = ((Settings)(global::System.Configuration.ApplicationSettingsBase.Synchronized(new Settings())));
+
+        public static Settings Default
+        {
+            get
+            {
+                return defaultInstance;
+            }
+        }
+    }
+}

WindowsFormsApp1/Properties/Settings.settings

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='utf-8'?>
+<SettingsFile xmlns="http://schemas.microsoft.com/VisualStudio/2004/01/settings" CurrentProfile="(Default)">
+  <Profiles>
+    <Profile Name="(Default)" />
+  </Profiles>
+  <Settings />
+</SettingsFile>

WindowsFormsApp1/Test/BaseTextBox.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using WindowsFormsApp1.classes;
+using WindowsFormsApp1.OP;
+
+namespace WindowsFormsApp1.Test
+{
+    public class BaseTextBox : ABaseTexBox, OP.IObserver<string>
+    {
+        public BaseTextBox() : base()
+        {
+            ForeColor = Color.White;
+            BackColor = Color.DarkOrange;
+        }
+
+        public override string Description { get; set; }
+
+        public void Update(ISubject<string> subject)
+        {
+
+            MessageBox.Show(subject.GetState());
+        }
+    }
+}

WindowsFormsApp1/Test/ExtendedTB.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.ComponentModel;
+
+namespace WindowsFormsApp1.Test
+{
+    public class ExtendedTB : BaseTextBox
+    {
+        public ExtendedTB() : base()
+        {
+            ForeColor = Color.White;
+            BackColor = Color.Red;
+        }
+
+        public override void Reset()
+        {
+            base.Reset();
+            Text = "Resetted!";
+        }
+
+        [DefaultValue(typeof(Color), "Red")]
+        public Color BackColor
+        {
+            get { return base.BackColor; }
+            set { base.BackColor = value; }
+        }
+
+        public override string Description { get => base.Description; set => base.Description = value; }
+    }
+}

WindowsFormsApp1/WindowsFormsApp1.csproj

@@ -0,0 +1,98 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{79AF4BD6-6931-4E8C-81D1-6464F70C480D}</ProjectGuid>
+    <OutputType>WinExe</OutputType>
+    <RootNamespace>WindowsFormsApp1</RootNamespace>
+    <AssemblyName>WindowsFormsApp1</AssemblyName>
+    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Deployment" />
+    <Reference Include="System.Drawing" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Windows.Forms" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="classes\ATextBox.cs">
+      <SubType>Component</SubType>
+    </Compile>
+    <Compile Include="Form1.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="Form1.Designer.cs">
+      <DependentUpon>Form1.cs</DependentUpon>
+    </Compile>
+    <Compile Include="OP\ClassObserver.cs" />
+    <Compile Include="OP\IObserver.cs" />
+    <Compile Include="OP\ISubject.cs" />
+    <Compile Include="OP\PropertyObserver.cs" />
+    <Compile Include="OP\Subject.cs" />
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Test\BaseTextBox.cs">
+      <SubType>Component</SubType>
+    </Compile>
+    <Compile Include="Test\ExtendedTB.cs">
+      <SubType>Component</SubType>
+    </Compile>
+    <EmbeddedResource Include="Form1.resx">
+      <DependentUpon>Form1.cs</DependentUpon>
+    </EmbeddedResource>
+    <EmbeddedResource Include="Properties\Resources.resx">
+      <Generator>ResXFileCodeGenerator</Generator>
+      <LastGenOutput>Resources.Designer.cs</LastGenOutput>
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
+    <Compile Include="Properties\Resources.Designer.cs">
+      <AutoGen>True</AutoGen>
+      <DependentUpon>Resources.resx</DependentUpon>
+    </Compile>
+    <None Include="ClassDiagram1.cd" />
+    <None Include="Properties\Settings.settings">
+      <Generator>SettingsSingleFileGenerator</Generator>
+      <LastGenOutput>Settings.Designer.cs</LastGenOutput>
+    </None>
+    <Compile Include="Properties\Settings.Designer.cs">
+      <AutoGen>True</AutoGen>
+      <DependentUpon>Settings.settings</DependentUpon>
+      <DesignTimeSharedInput>True</DesignTimeSharedInput>
+    </Compile>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="App.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>

WindowsFormsApp1/classes/ATextBox.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using WindowsFormsApp1.Test;
+
+namespace WindowsFormsApp1.classes
+{
+    public abstract class ABaseTexBox : TextBox
+    {
+        public virtual void Reset() => Text = string.Empty;
+
+        private protected void ResetProperties()
+        {
+            Name = string.Empty;
+            Description = string.Empty;
+        }
+
+        abstract public string Description { get; set; }
+    }
+}