disable button instead of hiding, remove empty values before saving, update dialog result handling

Controls.LookupGrid/LookupControl.vbproj

@@ -151,6 +151,9 @@
     <EmbeddedResource Include="LookupControl.resx">
       <DependentUpon>LookupControl.vb</DependentUpon>
     </EmbeddedResource>
+    <EmbeddedResource Include="LookupControl2.resx">
+      <DependentUpon>LookupControl2.vb</DependentUpon>
+    </EmbeddedResource>
     <EmbeddedResource Include="My Project\licenses.licx" />
     <EmbeddedResource Include="My Project\Resources.resx">
       <Generator>VbMyResourcesResXFileCodeGenerator</Generator>

Controls.LookupGrid/LookupControl2.resx

@@ -0,0 +1,123 @@
+<?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>
+  <metadata name="$this.TrayLargeIcon" type="System.Boolean, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
+    <value>False</value>
+  </metadata>
+</root>

Controls.LookupGrid/LookupControl2.vb

@@ -22,7 +22,6 @@ Public Class LookupControl2
             Return _SelectedValues
         End Get
         Set(value As List(Of String))
-            _SelectedValues = value
             UpdateSelectedValues(value)
         End Set
     End Property
@@ -31,19 +30,20 @@ Public Class LookupControl2
             Return _ReadOnly
         End Get
         Set(value As Boolean)
-            SetButtonVisibility(Not value)
+            SetFormButtonEnabled(Not value)
             _ReadOnly = value
         End Set
     End Property
 
     Private ReadOnly _LookupFormButton As EditorButton
 
+    Private Const TAG_DROPDOWN = "openDropdown"
     Private Const TAG_BUTTON_LOOKUP_FORM = "openLookupForm"
     Private Const TEXT_NO_RECORDS = "Keine Datensätze ausgewählt"
     Private Const TEXT_ONE_RECORD = "Ein Datensatz ausgewählt"
     Private Const TEXT_N_RECORDS = "{0} Datensätze ausgewählt"
 
-    Private _SelectedValues As List(Of String)
+    Private _SelectedValues As New List(Of String)
     Private _ReadOnly As Boolean = False
 
     Shared Sub New()
@@ -60,6 +60,7 @@ Public Class LookupControl2
             .Tag = TAG_BUTTON_LOOKUP_FORM
         }
 
+        Properties.Buttons.Item(0).Tag = TAG_DROPDOWN
         Properties.Buttons.AddRange({_LookupFormButton})
 
         AddHandler ButtonClick, AddressOf HandleButtonClick
@@ -67,13 +68,23 @@ Public Class LookupControl2
         AddHandler QueryPopUp, AddressOf HandleQueryPopup
     End Sub
 
-    Private Sub SetButtonVisibility(Visible As Boolean)
+    Private Sub SetFormButtonEnabled(Enabled As Boolean)
         Dim oButton As EditorButton = Properties.Buttons.
             Where(Function(b) b.Tag = TAG_BUTTON_LOOKUP_FORM).
             FirstOrDefault()
 
         If oButton IsNot Nothing Then
-            oButton.Visible = Visible
+            oButton.Enabled = Enabled
+        End If
+    End Sub
+
+    Private Sub SetDropdownButtonEnabled(Enabled As Boolean)
+        Dim oButton As EditorButton = Properties.Buttons.
+            Where(Function(b) b.Tag = TAG_DROPDOWN).
+            FirstOrDefault()
+
+        If oButton IsNot Nothing Then
+            oButton.Enabled = Enabled
         End If
     End Sub
 
@@ -106,14 +117,7 @@ Public Class LookupControl2
 
                     If oResult = Windows.Forms.DialogResult.OK Then
                         Dim oValues = oForm.SelectedValues
-
                         UpdateSelectedValues(oValues)
-                        SelectedValues = oValues
-                    ElseIf oResult = Windows.Forms.DialogResult.Cancel Then
-                        Dim oValues = New List(Of String)
-
-                        UpdateSelectedValues(oValues)
-                        SelectedValues = oValues
                     End If
                 End Using
         End Select
@@ -124,6 +128,8 @@ Public Class LookupControl2
             Exit Sub
         End If
 
+        Values.RemoveAll(Function(v) String.IsNullOrEmpty(v))
+
         If MultiSelect = True Then
             Properties.DataSource = Values
 
@@ -140,6 +146,8 @@ Public Class LookupControl2
             Text = Values.FirstOrDefault()
             EditValue = Nothing
         End If
+
+        _SelectedValues = Values
     End Sub
 
     Private Function GetLookupForm() As frmLookupGrid

Controls.LookupGrid/frmLookupGrid.Designer.vb

@@ -69,6 +69,7 @@ Partial Class frmLookupGrid
         'btnClear
         '
         Me.btnClear.Anchor = CType((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
+        Me.btnClear.DialogResult = System.Windows.Forms.DialogResult.OK
         Me.btnClear.Location = New System.Drawing.Point(236, 6)
         Me.btnClear.Name = "btnClear"
         Me.btnClear.Size = New System.Drawing.Size(136, 23)

Controls.LookupGrid/frmLookupGrid.vb

@@ -139,7 +139,7 @@ Public Class frmLookupGrid
     Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click
         SelectedValues = New List(Of String)
 
-        DialogResult = DialogResult.Cancel
+        DialogResult = DialogResult.OK
         Close()
     End Sub