select case Type

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  • PJ6
    #1

    select case Type

    Select Case o.GetType
    Case = GetType(SomeRan domTypeName)
    '...
    End Select

    Why doesn't this work? Can I make it work or am I stuck with ElseIf for a
    long list?

    Paul


    Tags: gettype case
    • Jay B. Harlow [MVP - Outlook]
      #2
      Re: select case Type

      Paul,
      | Why doesn't this work?
      Case requires "elementary data type". Type is not a "elementary ", but rather
      it is a class.

      http://msdn2.microsoft.com/en-us/library/cy37t14y.aspx


      | Can I make it work or am I stuck with ElseIf for a
      | long list?
      When checking for specific types, I would use a ElseIf as it ensures that
      derived types are handled correctly.

      You can get a select case to work, by using the type names, however then you
      are limited to the type names & if you ever change the name of the type your
      select case will break.

      Something like:
      | Select Case o.GetType.ToStr ing
      | Case "SomeNameSpace. SomeRandomTypeN ame"
      | '...
      | End Select


      --
      Hope this helps
      Jay B. Harlow [MVP - Outlook]
      ..NET Application Architect, Enthusiast, & Evangelist
      T.S. Bradley - http://www.tsbradley.net


      "PJ6" <noone@nowhere. net> wrote in message
      news:ulePazmgGH A.1320@TK2MSFTN GP04.phx.gbl...
      | Select Case o.GetType
      | Case = GetType(SomeRan domTypeName)
      | '...
      | End Select
      |
      | Why doesn't this work? Can I make it work or am I stuck with ElseIf for a
      | long list?
      |
      | Paul
      |
      |


        Comment

        • PJ6
          #3
          Re: select case Type

          OK, but I don't see why they have that restriction, why the "Is" operator
          here cannot function the same as the "Is" operator elsewhere. It would seem
          to me an arbitrary and rather unnecessary break in convention.

          Paul

          "Jay B. Harlow [MVP - Outlook]" <Jay_Harlow_MVP @tsbradley.net> wrote in
          message news:uyRtuLngGH A.3456@TK2MSFTN GP05.phx.gbl...[color=blue]
          > Paul,
          > | Why doesn't this work?
          > Case requires "elementary data type". Type is not a "elementary ", but
          > rather
          > it is a class.
          >
          > http://msdn2.microsoft.com/en-us/library/cy37t14y.aspx
          >
          >
          > | Can I make it work or am I stuck with ElseIf for a
          > | long list?
          > When checking for specific types, I would use a ElseIf as it ensures that
          > derived types are handled correctly.
          >
          > You can get a select case to work, by using the type names, however then
          > you
          > are limited to the type names & if you ever change the name of the type
          > your
          > select case will break.
          >
          > Something like:
          > | Select Case o.GetType.ToStr ing
          > | Case "SomeNameSpace. SomeRandomTypeN ame"
          > | '...
          > | End Select
          >
          >
          > --
          > Hope this helps
          > Jay B. Harlow [MVP - Outlook]
          > .NET Application Architect, Enthusiast, & Evangelist
          > T.S. Bradley - http://www.tsbradley.net
          >
          >
          > "PJ6" <noone@nowhere. net> wrote in message
          > news:ulePazmgGH A.1320@TK2MSFTN GP04.phx.gbl...
          > | Select Case o.GetType
          > | Case = GetType(SomeRan domTypeName)
          > | '...
          > | End Select
          > |
          > | Why doesn't this work? Can I make it work or am I stuck with ElseIf for
          > a
          > | long list?
          > |
          > | Paul
          > |
          > |
          >
          >[/color]


            Comment

            • Jay B. Harlow [MVP - Outlook]
              #4
              Re: select case Type

              PJ6
              There is no "Is" operator in a Select Case per se!

              Notice that in a Select Case that "Is" is used to introduce a comparison
              operator, such as <, >, <=, >=, =, or <>. That is "[Is] comparisonopera tor".

              IMHO: using "Case Is < 10" reads better then "Case < 10", however that is
              largely personal preference.

              Its similar to the "Is" keyword in the "TypeOf Is" operator.
              --
              Hope this helps
              Jay B. Harlow [MVP - Outlook]
              ..NET Application Architect, Enthusiast, & Evangelist
              T.S. Bradley - http://www.tsbradley.net


              "PJ6" <noone@nowhere. net> wrote in message
              news:OhJm0kngGH A.1208@TK2MSFTN GP02.phx.gbl...
              | OK, but I don't see why they have that restriction, why the "Is" operator
              | here cannot function the same as the "Is" operator elsewhere. It would
              seem
              | to me an arbitrary and rather unnecessary break in convention.
              |
              | Paul
              |
              | "Jay B. Harlow [MVP - Outlook]" <Jay_Harlow_MVP @tsbradley.net> wrote in
              | message news:uyRtuLngGH A.3456@TK2MSFTN GP05.phx.gbl...
              | > Paul,
              | > | Why doesn't this work?
              | > Case requires "elementary data type". Type is not a "elementary ", but
              | > rather
              | > it is a class.
              | >
              | > http://msdn2.microsoft.com/en-us/library/cy37t14y.aspx
              | >
              | >
              | > | Can I make it work or am I stuck with ElseIf for a
              | > | long list?
              | > When checking for specific types, I would use a ElseIf as it ensures
              that
              | > derived types are handled correctly.
              | >
              | > You can get a select case to work, by using the type names, however then
              | > you
              | > are limited to the type names & if you ever change the name of the type
              | > your
              | > select case will break.
              | >
              | > Something like:
              | > | Select Case o.GetType.ToStr ing
              | > | Case "SomeNameSpace. SomeRandomTypeN ame"
              | > | '...
              | > | End Select
              | >
              | >
              | > --
              | > Hope this helps
              | > Jay B. Harlow [MVP - Outlook]
              | > .NET Application Architect, Enthusiast, & Evangelist
              | > T.S. Bradley - http://www.tsbradley.net
              | >
              | >
              | > "PJ6" <noone@nowhere. net> wrote in message
              | > news:ulePazmgGH A.1320@TK2MSFTN GP04.phx.gbl...
              | > | Select Case o.GetType
              | > | Case = GetType(SomeRan domTypeName)
              | > | '...
              | > | End Select
              | > |
              | > | Why doesn't this work? Can I make it work or am I stuck with ElseIf
              for
              | > a
              | > | long list?
              | > |
              | > | Paul
              | > |
              | > |
              | >
              | >
              |
              |


                Comment

                • Herfried K. Wagner [MVP]
                  #5
                  Re: select case Type

                  "PJ6" <noone@nowhere. net> schrieb:[color=blue]
                  > Select Case o.GetType
                  > Case = GetType(SomeRan domTypeName)
                  > '...
                  > End Select
                  >
                  > Why doesn't this work? Can I make it work or am I stuck with ElseIf for a
                  > long list?[/color]


                  \\\
                  Dim t As Type = o.GetType()
                  Select Case True
                  Case t Is GetType(SomeRan domTypeName)
                  ...
                  Case t Is GetType(...)
                  ...
                  ...
                  End Select
                  ///

                  - or -

                  \\\
                  Select Case True
                  Case TypeOf t Is SomeRandomType
                  ...
                  Case TypeOf t Is ...
                  ...
                  ...
                  End Select
                  ///

                  --
                  M S Herfried K. Wagner
                  M V P <URL:http://dotnet.mvps.org/>
                  V B <URL:http://classicvb.org/petition/>

                    Comment

                    • Roland
                      #6
                      Re: select case Type

                      I am using

                      Select case o.getType.name
                      Case (SomerandomType Name)
                      Case ...
                      End Select

                      works as a charm since it is "o.getType.name " is a string
                      Roland

                      "PJ6" <noone@nowhere. net> wrote in message
                      news:ulePazmgGH A.1320@TK2MSFTN GP04.phx.gbl...[color=blue]
                      > Select Case o.GetType
                      > Case = GetType(SomeRan domTypeName)
                      > '...
                      > End Select
                      >
                      > Why doesn't this work? Can I make it work or am I stuck with ElseIf for a
                      > long list?
                      >
                      > Paul
                      >[/color]


                        Comment

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