diff --git a/CommonControls/FileIoHandler.cs b/CommonControls/FileIoHandler.cs
index 9fc84df2..45215180 100644
--- a/CommonControls/FileIoHandler.cs
+++ b/CommonControls/FileIoHandler.cs
@@ -38,6 +38,19 @@ public static string ShowFolder(string folder)
             return browser.Root;
         }
 
+        /// <summary>
+        /// Shows the login screen.
+        /// </summary>
+        /// <returns>Connection String</returns>
+        public static string ShowLoginScreen()
+        {
+            var login = new SqlLogin();
+            _ = login.ShowDialog();
+
+            return login.View.ConnectionString;
+        }
+
+
         /// <summary>
         ///     Looks up a file
         ///     Returns the PathObject
diff --git a/CommonControls/SqlLogin.xaml b/CommonControls/SqlLogin.xaml
index 2c030bd2..b3ba12ff 100644
--- a/CommonControls/SqlLogin.xaml
+++ b/CommonControls/SqlLogin.xaml
@@ -8,7 +8,7 @@
         mc:Ignorable="d"
         Title="Connect to Server" Height="450" Width="450">
     <Window.DataContext>
-        <local:SqlView x:Name="View" />
+        <local:SqlView x:Name="View" x:FieldModifier="public" />
     </Window.DataContext>
     <Grid>
         <Grid.RowDefinitions>
@@ -38,7 +38,7 @@
         <TextBox  Grid.ColumnSpan="2" Grid.Column="2" Grid.Row="1" TextWrapping="Wrap" Text="{Binding Path=Server, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
         <TextBox  Grid.ColumnSpan="2" Grid.Column="2" Grid.Row="3" TextWrapping="Wrap" Text="{Binding Path=Database, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
         <Button  Content="Connect" Grid.Column="2" HorizontalAlignment="Left"  Grid.Row="7" VerticalAlignment="Top"  Command="{Binding ConnectCommand}"/>
-        <Button  Content="Close" Grid.Column="3" HorizontalAlignment="Left"  Grid.Row="7" VerticalAlignment="Top" Click="Button_Click"/>
+        <Button  Content="Close" Grid.Column="3" HorizontalAlignment="Left"  Grid.Row="7" VerticalAlignment="Top" Command="{Binding CloseCommand}"/>
         <TextBox Grid.ColumnSpan="2" Grid.Column="2" HorizontalAlignment="Stretch" Grid.Row="9" TextWrapping="Wrap" VerticalAlignment="Stretch" Text="{Binding Path=Log, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" IsEnabled="False"/>
     </Grid>
 </Window>
diff --git a/CommonControls/SqlLogin.xaml.cs b/CommonControls/SqlLogin.xaml.cs
index c4211398..8d416db8 100644
--- a/CommonControls/SqlLogin.xaml.cs
+++ b/CommonControls/SqlLogin.xaml.cs
@@ -29,15 +29,5 @@ public SqlLogin()
         {
             InitializeComponent();
         }
-
-        /// <summary>
-        /// Handles the Click event of the Button control.
-        /// </summary>
-        /// <param name="sender">The source of the event.</param>
-        /// <param name="e">The <see cref="RoutedEventArgs"/> instance containing the event data.</param>
-        private void Button_Click(object sender, RoutedEventArgs e)
-        {
-            Close();
-        }
     }
 }
diff --git a/CommonControls/SqlView.cs b/CommonControls/SqlView.cs
index 255fc885..951b887a 100644
--- a/CommonControls/SqlView.cs
+++ b/CommonControls/SqlView.cs
@@ -11,6 +11,7 @@
 // ReSharper disable MemberCanBePrivate.Global
 
 using System.ComponentModel;
+using System.Windows;
 using System.Windows.Input;
 using ViewModel;
 
@@ -28,6 +29,11 @@ public sealed class SqlView : INotifyPropertyChanged
         /// </summary>
         private ICommand _connectCommand;
 
+        /// <summary>
+        /// The close command
+        /// </summary>
+        private ICommand _closeCommand;
+
         /// <summary>
         ///     The data base
         /// </summary>
@@ -136,6 +142,15 @@ public string Log
         public ICommand ConnectCommand =>
             _connectCommand ??= new DelegateCommand<object>(ConnectAction, CanExecute);
 
+        /// <summary>
+        /// Gets the close command.
+        /// </summary>
+        /// <value>
+        /// The close command.
+        /// </value>
+        public ICommand CloseCommand =>
+            _closeCommand ??= new DelegateCommand<object>(CloseAction, CanExecute);
+
         /// <summary>
         ///     Gets the connection string.
         /// </summary>
@@ -153,7 +168,6 @@ public string Log
         /// </value>
         public string AddLog { get; set; }
 
-
         /// <inheritdoc />
         /// <summary>
         ///     Triggers if an Attribute gets changed
@@ -194,5 +208,14 @@ private void ConnectAction(object obj)
             var connect = new SqlConnect(Database, Server, IsActive);
             ConnectionString = connect.GetConnectionString();
         }
+
+        /// <summary>
+        ///     Closes the app
+        /// </summary>
+        /// <param name="obj">The object.</param>
+        private void CloseAction(object obj)
+        {
+            Application.Current.Shutdown();
+        }
     }
 }
diff --git a/CommonLibraryGuiTests/CommonCtrl.cs b/CommonLibraryGuiTests/CommonCtrl.cs
index c65ee95d..ac5d7800 100644
--- a/CommonLibraryGuiTests/CommonCtrl.cs
+++ b/CommonLibraryGuiTests/CommonCtrl.cs
@@ -6,6 +6,7 @@
  * PROGRAMER:   Peter Geinitz (Wayfarer)
  */
 
+using System;
 using System.Collections.Generic;
 using System.Threading;
 using CommonControls;
@@ -113,5 +114,24 @@ public void Win32Api()
             //TODO Test in Live environment
             Assert.AreNotEqual(512, Win32Enums.MouseEvents.WmMousemove, "checked out");
         }
+
+        /// <summary>
+        /// Test of the ConnectionString Dialog.
+        /// </summary>
+        [Test]
+        [Apartment(ApartmentState.STA)]
+        public void ConnectionString()
+        {
+            var login = new SqlLogin();
+            login.Show();
+            login.View.Server = "SqlServer";
+            login.View.Database = @"MyDB\Hello";
+            login.View.ConnectCommand.Execute(null);
+            var result = login.View.ConnectionString;
+            login.Close();
+
+            Assert.IsTrue(result.Equals(@"PersistSecurity Info= False;TrustServerCertificate=False;Integrated Security=True;SqlServer;MyDB\Hello", StringComparison.Ordinal),
+                string.Concat("Wrong Connection string: ", result));
+        }
     }
 }
diff --git a/CommonLibraryTests/CommonLibraryTests.csproj b/CommonLibraryTests/CommonLibraryTests.csproj
index 96ac61c6..d61ecfad 100644
--- a/CommonLibraryTests/CommonLibraryTests.csproj
+++ b/CommonLibraryTests/CommonLibraryTests.csproj
@@ -49,6 +49,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\CommonControls\CommonControls.csproj" />
+    <ProjectReference Include="..\Communication\Communication.csproj" />
     <ProjectReference Include="..\ExtendedSystemObjects\ExtendedSystemObjects.csproj" />
     <ProjectReference Include="..\FileHandler\FileHandler.csproj" />
     <ProjectReference Include="..\ImageCompare\ImageCompare.csproj" />
diff --git a/CommonLibraryTestsCommunication/Communication.cs b/CommonLibraryTests/Communication.cs
similarity index 79%
rename from CommonLibraryTestsCommunication/Communication.cs
rename to CommonLibraryTests/Communication.cs
index 1ed1f9c3..e83dc5b8 100644
--- a/CommonLibraryTestsCommunication/Communication.cs
+++ b/CommonLibraryTests/Communication.cs
@@ -1,6 +1,6 @@
 /*
  * COPYRIGHT:   See COPYING in the top level directory
- * PROJECT:     CommonLibraryTestsCommunication
+ * PROJECT:     CommonLibraryTests
  * FILE:        Communication.cs
  * PURPOSE:     Test for our communication
  * PROGRAMER:   Peter Geinitz (Wayfarer)
@@ -10,13 +10,19 @@
 using Communication;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace CommonLibraryTestsCommunication
+namespace CommonLibraryTests
 {
     [TestClass]
     public class Communication
     {
+        /// <summary>
+        /// The path
+        /// </summary>
         private readonly string _path = Path.Combine(Directory.GetCurrentDirectory(), nameof(Communication));
 
+        /// <summary>
+        /// Communicationses this instance.
+        /// </summary>
         [TestMethod]
         public void Communications()
         {
diff --git a/CommonLibraryTestsCommunication/CommonLibraryTestsCommunication.csproj b/CommonLibraryTestsCommunication/CommonLibraryTestsCommunication.csproj
deleted file mode 100644
index dbe8431a..00000000
--- a/CommonLibraryTestsCommunication/CommonLibraryTestsCommunication.csproj
+++ /dev/null
@@ -1,20 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-  <PropertyGroup>
-    <TargetFramework>net5.0</TargetFramework>
-
-    <IsPackable>false</IsPackable>
-  </PropertyGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.4" />
-    <PackageReference Include="MSTest.TestAdapter" Version="2.2.3" />
-    <PackageReference Include="MSTest.TestFramework" Version="2.2.3" />
-    <PackageReference Include="coverlet.collector" Version="3.0.2" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <ProjectReference Include="..\Communication\Communication.csproj" />
-  </ItemGroup>
-
-</Project>
diff --git a/CoreLibrary.sln b/CoreLibrary.sln
index 586eeab6..89523e4e 100644
--- a/CoreLibrary.sln
+++ b/CoreLibrary.sln
@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.8.34330.188
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.34301.259
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ViewModel", "ViewModel\ViewModel.csproj", "{9B2741D2-443A-4136-B9A4-1191686DA4AD}"
 EndProject
@@ -51,8 +51,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Communication", "Communicat
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LightVector", "LightVector\LightVector.csproj", "{8DD286ED-2358-47E1-BD4D-B4DCB550681E}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "CommonLibraryTestsCommunication", "CommonLibraryTestsCommunication\CommonLibraryTestsCommunication.csproj", "{B98A7BCE-4188-4E1E-B733-A89906049BEC}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Mathematics", "Mathematics\Mathematics.csproj", "{03B1DB00-54D5-4095-BE71-B26CFA923420}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Imaging", "Imaging\Imaging.csproj", "{810F6A32-3C86-4DB8-B3C3-F9CF438A1D47}"
@@ -143,10 +141,6 @@ Global
 		{8DD286ED-2358-47E1-BD4D-B4DCB550681E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{8DD286ED-2358-47E1-BD4D-B4DCB550681E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{8DD286ED-2358-47E1-BD4D-B4DCB550681E}.Release|Any CPU.Build.0 = Release|Any CPU
-		{B98A7BCE-4188-4E1E-B733-A89906049BEC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{B98A7BCE-4188-4E1E-B733-A89906049BEC}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{B98A7BCE-4188-4E1E-B733-A89906049BEC}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{B98A7BCE-4188-4E1E-B733-A89906049BEC}.Release|Any CPU.Build.0 = Release|Any CPU
 		{03B1DB00-54D5-4095-BE71-B26CFA923420}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{03B1DB00-54D5-4095-BE71-B26CFA923420}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{03B1DB00-54D5-4095-BE71-B26CFA923420}.Release|Any CPU.ActiveCfg = Release|Any CPU