Delegates and AddressOf

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  • kaczmar2@hotmail.com
    #1

    Delegates and AddressOf

    I have a custom web control that is called from an aspx page. The
    custom control dynamically renders out buttons via a public method
    (AddButton). One of the attributes of the method is a delegate, so on
    the button click event I can invoke a method at the calling page
    level. Everything works great if the control is written in C#, but it
    needs to be written in VB.NET.

    In C#, in the control I can attach an event like so:

    NewButton.Click += new EventHandler(Me thod);

    where "Method" is the name of the delegate parameter in the AddButton
    function.


    In VB.NET, I try to attach an event like so:

    AddHandler NewButton.Click , AddressOf Method

    This throws the error: 'AddressOf' operand must be the name of a
    method (without parentheses).

    If I pass AddressOf a method declared at the page level, it works, but
    I need to pass it the delegate param that is passed in to the
    function. How can I do this in VB.NET? code is below. Thanks for
    your help!


    Here is the code on the aspx page:

    // Button_Click is a delegate, and is defined in the calling page:
    MyCustomControl 1.AddButton("bt nTest", "A Test", Button_Click);


    USER CONTROL CODE : C# -- this works...

    public delegate void MyDelegate(obje ct sender, EventArgs e);

    public void AddButton(strin g Id, string ButtonText, MyDelegate Method)
    {
    MyCoolButton NewButton = new Button();

    NewButton.ID = Id;
    NewButton.Text = ButtonText;

    //NewButton.Click += new EventHandler(Ev entHandler);
    NewButton.Click += new EventHandler(Me thod);
    Buttons.Add(New Button);
    }


    USER CONTROL CODE : VB.NET - this does not work...

    Public Delegate Sub MyDelegate(ByVa l sender As Object, ByVal e As
    EventArgs)

    Public Sub AddButton(ByVal Id As String, ByVal ButtonText As String,
    ByVal Method As MyDelegate)

    Dim NewButton As New Button

    NewButton.ID = Id
    NewButton.Text = ButtonText

    AddHandler NewButton.Click , AddressOf Method ' *** THIS IS THE LINE
    WITH THE ERROR

    Buttons.Add(New Button)

    End Sub

    Tags: None
    • =?Utf-8?B?RGF2aWQgQW50b24=?=
      #2
      RE: Delegates and AddressOf

      Get rid of the "AddressOf" . It would be needed if 'Method' was an actual
      method, but not for a delegate type instance.
      --
      David Anton
      Source Code Converters
      https://www.tangiblesoftwaresolutions.com
      Source code converters: Convert between C#, C++, Java, and VB with the most accurate and reliable source code converters

      Instant C#: VB to C# converter
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      "kaczmar2@hotma il.com" wrote:
      I have a custom web control that is called from an aspx page. The
      custom control dynamically renders out buttons via a public method
      (AddButton). One of the attributes of the method is a delegate, so on
      the button click event I can invoke a method at the calling page
      level. Everything works great if the control is written in C#, but it
      needs to be written in VB.NET.
      >
      In C#, in the control I can attach an event like so:
      >
      NewButton.Click += new EventHandler(Me thod);
      >
      where "Method" is the name of the delegate parameter in the AddButton
      function.
      >
      >
      In VB.NET, I try to attach an event like so:
      >
      AddHandler NewButton.Click , AddressOf Method
      >
      This throws the error: 'AddressOf' operand must be the name of a
      method (without parentheses).
      >
      If I pass AddressOf a method declared at the page level, it works, but
      I need to pass it the delegate param that is passed in to the
      function. How can I do this in VB.NET? code is below. Thanks for
      your help!
      >
      >
      Here is the code on the aspx page:
      >
      // Button_Click is a delegate, and is defined in the calling page:
      MyCustomControl 1.AddButton("bt nTest", "A Test", Button_Click);
      >
      >
      USER CONTROL CODE : C# -- this works...
      >
      public delegate void MyDelegate(obje ct sender, EventArgs e);
      >
      public void AddButton(strin g Id, string ButtonText, MyDelegate Method)
      {
      MyCoolButton NewButton = new Button();
      >
      NewButton.ID = Id;
      NewButton.Text = ButtonText;
      >
      //NewButton.Click += new EventHandler(Ev entHandler);
      NewButton.Click += new EventHandler(Me thod);
      Buttons.Add(New Button);
      }
      >
      >
      USER CONTROL CODE : VB.NET - this does not work...
      >
      Public Delegate Sub MyDelegate(ByVa l sender As Object, ByVal e As
      EventArgs)
      >
      Public Sub AddButton(ByVal Id As String, ByVal ButtonText As String,
      ByVal Method As MyDelegate)
      >
      Dim NewButton As New Button
      >
      NewButton.ID = Id
      NewButton.Text = ButtonText
      >
      AddHandler NewButton.Click , AddressOf Method ' *** THIS IS THE LINE
      WITH THE ERROR
      >
      Buttons.Add(New Button)
      >
      End Sub
      >
      >

        Comment

        • kaczmar2@hotmail.com
          #3
          Re: Delegates and AddressOf

          I have tried that as well. If I change the erroneous line to:

          AddHandler NewButton.Click , Method

          I get thiis compiler-time error:

          Value of type 'TestWebCustomC ontrol.MyCustom Control.MyDeleg ate' cannot
          be converted to 'System.EventHa ndler'.


          Any other suggestions? I have been going crazy!

          On May 4, 8:04 pm, David Anton <DavidAn...@dis cussions.micros oft.com>
          wrote:
          Get rid of the "AddressOf" . It would be needed if 'Method' was an actual
          method, but not for a delegate type instance.
          --
          David Antonwww.tangib lesoftwaresolut ions.com
          Instant C#: VB to C# converter
          Instant VB: C# to VB converter
          C++ to C# Converter: converts C++ to C#
          Instant C++: converts C# or VB to C++/CLI
          >
          >
          >
          "kaczm...@hotma il.com" wrote:
          I have a custom web control that is called from an aspx page. The
          custom control dynamically renders out buttons via a public method
          (AddButton). One of the attributes of the method is a delegate, so on
          the button click event I can invoke a method at the calling page
          level. Everything works great if the control is written in C#, but it
          needs to be written in VB.NET.
          >
          In C#, in the control I can attach an event like so:
          >
          NewButton.Click += new EventHandler(Me thod);
          >
          where "Method" is the name of the delegate parameter in the AddButton
          function.
          >
          In VB.NET, I try to attach an event like so:
          >
          AddHandler NewButton.Click , AddressOf Method
          >
          This throws the error: 'AddressOf' operand must be the name of a
          method (without parentheses).
          >
          If I pass AddressOf a method declared at the page level, it works, but
          I need to pass it the delegate param that is passed in to the
          function. How can I do this in VB.NET? code is below. Thanks for
          your help!
          >
          Here is the code on the aspx page:
          >
          // Button_Click is a delegate, and is defined in the calling page:
          MyCustomControl 1.AddButton("bt nTest", "A Test", Button_Click);
          >
          USER CONTROL CODE : C# -- this works...
          >
          public delegate void MyDelegate(obje ct sender, EventArgs e);
          >
          public void AddButton(strin g Id, string ButtonText, MyDelegate Method)
          {
          MyCoolButton NewButton = new Button();
          >
          NewButton.ID = Id;
          NewButton.Text = ButtonText;
          >
          //NewButton.Click += new EventHandler(Ev entHandler);
          NewButton.Click += new EventHandler(Me thod);
          Buttons.Add(New Button);
          }
          >
          USER CONTROL CODE : VB.NET - this does not work...
          >
          Public Delegate Sub MyDelegate(ByVa l sender As Object, ByVal e As
          EventArgs)
          >
          Public Sub AddButton(ByVal Id As String, ByVal ButtonText As String,
          ByVal Method As MyDelegate)
          >
          Dim NewButton As New Button
          >
          NewButton.ID = Id
          NewButton.Text = ButtonText
          >
          AddHandler NewButton.Click , AddressOf Method ' *** THIS IS THE LINE
          WITH THE ERROR
          >
          Buttons.Add(New Button)
          >
          End Sub- Hide quoted text -
          >
          - Show quoted text -

            Comment

            • kaczmar2@hotmail.com
              #4
              Re: Delegates and AddressOf

              Also, I did try changing the signature of my Method to compensate for
              the above compile-time error:

              Public Sub AddButton(ByVal Id As String, ByVal ButtonText As String,
              ByVal Method As System.EventHan dler)
              ....
              AddHandler NewButton.Click , Method ' This will no longer throw a
              compile error...

              But then the event isn't raised when I click the button.


              On May 4, 8:04 pm, David Anton <DavidAn...@dis cussions.micros oft.com>
              wrote:
              Get rid of the "AddressOf" . It would be needed if 'Method' was an actual
              method, but not for a delegate type instance.
              --
              David Antonwww.tangib lesoftwaresolut ions.com
              Instant C#: VB to C# converter
              Instant VB: C# to VB converter
              C++ to C# Converter: converts C++ to C#
              Instant C++: converts C# or VB to C++/CLI
              >
              >
              >
              "kaczm...@hotma il.com" wrote:
              I have a custom web control that is called from an aspx page. The
              custom control dynamically renders out buttons via a public method
              (AddButton). One of the attributes of the method is a delegate, so on
              the button click event I can invoke a method at the calling page
              level. Everything works great if the control is written in C#, but it
              needs to be written in VB.NET.
              >
              In C#, in the control I can attach an event like so:
              >
              NewButton.Click += new EventHandler(Me thod);
              >
              where "Method" is the name of the delegate parameter in the AddButton
              function.
              >
              In VB.NET, I try to attach an event like so:
              >
              AddHandler NewButton.Click , AddressOf Method
              >
              This throws the error: 'AddressOf' operand must be the name of a
              method (without parentheses).
              >
              If I pass AddressOf a method declared at the page level, it works, but
              I need to pass it the delegate param that is passed in to the
              function. How can I do this in VB.NET? code is below. Thanks for
              your help!
              >
              Here is the code on the aspx page:
              >
              // Button_Click is a delegate, and is defined in the calling page:
              MyCustomControl 1.AddButton("bt nTest", "A Test", Button_Click);
              >
              USER CONTROL CODE : C# -- this works...
              >
              public delegate void MyDelegate(obje ct sender, EventArgs e);
              >
              public void AddButton(strin g Id, string ButtonText, MyDelegate Method)
              {
              MyCoolButton NewButton = new Button();
              >
              NewButton.ID = Id;
              NewButton.Text = ButtonText;
              >
              //NewButton.Click += new EventHandler(Ev entHandler);
              NewButton.Click += new EventHandler(Me thod);
              Buttons.Add(New Button);
              }
              >
              USER CONTROL CODE : VB.NET - this does not work...
              >
              Public Delegate Sub MyDelegate(ByVa l sender As Object, ByVal e As
              EventArgs)
              >
              Public Sub AddButton(ByVal Id As String, ByVal ButtonText As String,
              ByVal Method As MyDelegate)
              >
              Dim NewButton As New Button
              >
              NewButton.ID = Id
              NewButton.Text = ButtonText
              >
              AddHandler NewButton.Click , AddressOf Method ' *** THIS IS THE LINE
              WITH THE ERROR
              >
              Buttons.Add(New Button)
              >
              End Sub- Hide quoted text -
              >
              - Show quoted text -

                Comment

                • kaczmar2@hotmail.com
                  #5
                  Re: Delegates and AddressOf

                  Igonre that last post. The event did fire! I forgot to properly
                  register the envent handler in my page. It now works after I changed
                  the signature of my method to accept an EventArgs delegate instead of
                  my custom delegate type.

                  Thanks for your help.


                  On May 4, 10:01 pm, kaczm...@hotmai l.com wrote:
                  Also, I did try changing the signature of my Method to compensate for
                  the above compile-time error:
                  >
                  Public Sub AddButton(ByVal Id As String, ByVal ButtonText As String,
                  ByVal Method As System.EventHan dler)
                  ...
                  AddHandler NewButton.Click , Method ' This will no longer throw a
                  compile error...
                  >
                  But then the event isn't raised when I click the button.
                  >
                  On May 4, 8:04 pm, David Anton <DavidAn...@dis cussions.micros oft.com>
                  wrote:
                  >
                  >
                  >
                  Get rid of the "AddressOf" . It would be needed if 'Method' was an actual
                  method, but not for a delegate type instance.
                  --
                  David Antonwww.tangib lesoftwaresolut ions.com
                  Instant C#: VB to C# converter
                  Instant VB: C# to VB converter
                  C++ to C# Converter: converts C++ to C#
                  Instant C++: converts C# or VB to C++/CLI
                  >
                  "kaczm...@hotma il.com" wrote:
                  I have a custom web control that is called from an aspx page. The
                  custom control dynamically renders out buttons via a public method
                  (AddButton). One of the attributes of the method is a delegate, so on
                  the button click event I can invoke a method at the calling page
                  level. Everything works great if the control is written in C#, but it
                  needs to be written in VB.NET.
                  >
                  In C#, in the control I can attach an event like so:
                  >
                  NewButton.Click += new EventHandler(Me thod);
                  >
                  where "Method" is the name of the delegate parameter in the AddButton
                  function.
                  >
                  In VB.NET, I try to attach an event like so:
                  >
                  AddHandler NewButton.Click , AddressOf Method
                  >
                  This throws the error: 'AddressOf' operand must be the name of a
                  method (without parentheses).
                  >
                  If I pass AddressOf a method declared at the page level, it works, but
                  I need to pass it the delegate param that is passed in to the
                  function. How can I do this in VB.NET? code is below. Thanks for
                  your help!
                  >
                  Here is the code on the aspx page:
                  >
                  // Button_Click is a delegate, and is defined in the calling page:
                  MyCustomControl 1.AddButton("bt nTest", "A Test", Button_Click);
                  >
                  USER CONTROL CODE : C# -- this works...
                  >
                  public delegate void MyDelegate(obje ct sender, EventArgs e);
                  >
                  public void AddButton(strin g Id, string ButtonText, MyDelegate Method)
                  {
                  MyCoolButton NewButton = new Button();
                  >
                  NewButton.ID = Id;
                  NewButton.Text = ButtonText;
                  >
                  //NewButton.Click += new EventHandler(Ev entHandler);
                  NewButton.Click += new EventHandler(Me thod);
                  Buttons.Add(New Button);
                  }
                  >
                  USER CONTROL CODE : VB.NET - this does not work...
                  >
                  Public Delegate Sub MyDelegate(ByVa l sender As Object, ByVal e As
                  EventArgs)
                  >
                  Public Sub AddButton(ByVal Id As String, ByVal ButtonText As String,
                  ByVal Method As MyDelegate)
                  >
                  Dim NewButton As New Button
                  >
                  NewButton.ID = Id
                  NewButton.Text = ButtonText
                  >
                  AddHandler NewButton.Click , AddressOf Method ' *** THIS IS THE LINE
                  WITH THE ERROR
                  >
                  Buttons.Add(New Button)
                  >
                  End Sub- Hide quoted text -
                  >
                  - Show quoted text -- Hide quoted text -
                  >
                  - Show quoted text -

                    Comment

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