Base: migrate functions from other modules, add new functions

Base/StringEx.vb

@@ -21,6 +21,11 @@ Public Class StringEx
             If Char.IsLetterOrDigit(oChar) Then
                 oBuilder.Append(Char.ToLower(oChar))
                 oWasHyphen = False
+
+            ElseIf oChar = "_"c Or oChar = "-"c Then
+                oBuilder.Append(oChar)
+                oWasHyphen = True
+
             ElseIf Char.IsWhiteSpace(oChar) AndAlso Not oWasHyphen Then
                 oBuilder.Append("-"c)
                 oWasHyphen = True
@@ -111,6 +116,22 @@ Public Class StringEx
         Return GetChecksum(pStringToCheck).Substring(0, 32)
     End Function
 
+    Public Shared Function GetDateString() As String
+        Return $"{Now:yyyy\\MM\\dd}"
+    End Function
+
+    Public Shared Function GetDateString(pDate As Date) As String
+        Return $"{pDate:yyyy\\MM\\dd}"
+    End Function
+
+    Public Shared Function GetDateTimeString() As String
+        Return $"{Now:yyyy-MM-dd_hh-mm-ffff}"
+    End Function
+
+    Public Shared Function GetDateTimeString(pDate As Date) As String
+        Return $"{pDate:yyyy-MM-dd_hh-mm-ffff}"
+    End Function
+
     Friend Class InvalidChars
         Public Shared Filenames As String = Regex.Escape(New String(IO.Path.GetInvalidFileNameChars()))
         Public Shared Paths As String = Regex.Escape(New String(IO.Path.GetInvalidPathChars()))