DataGrid ButtonColumn/BoundColumn problem

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  • John
    #1

    DataGrid ButtonColumn/BoundColumn problem

    The ItemCommand event not getting fired when I add both a BoundColumn and a
    ButtonColumn to a datagrid. When I add a ButtonColumn by itself, everything
    works fine, but as soon as I add a BoundColumn, the ItemCommand event
    doesn't seem to get called.

    I've been struggling with this for too long now, I'm certain there's
    something I'm not getting. Here's the relevant code. Thanks in advance!

    // As is, this code does not correctly call the ItemCommand event handler.
    // Comment out AddIDColumn however and the ItemCommand event handler
    // is called when expected.
    private void Page_Load(objec t sender, System.EventArg s e) {
    AddIDColumn();
    AddButtonColumn ();
    dg.DataSource = GetDataSource() ;
    dg.DataKeyField = "employeeid ";
    if ( !IsPostBack )
    dg.DataBind();
    }

    private void AddIDColumn() {
    BoundColumn bound = new BoundColumn();
    bound.DataField = "EmployeeID ";
    bound.HeaderTex t = "EmployeeID ";
    dg.Columns.Add( bound );
    }

    private void AddButtonColumn () {
    ButtonColumn button = new ButtonColumn();
    button.ButtonTy pe = ButtonColumnTyp e.LinkButton;
    button.Text = "Click Me";
    button.CommandN ame = "whatever";
    dg.Columns.Add( button );
    }

    private void dg_ItemCommand( object source,
    System.Web.UI.W ebControls.Data GridCommandEven tArgs e) {
    dg.DataBind();
    }


    Tags: None
    • Giorgio Parmeggiani
      #2
      Re: DataGrid ButtonColumn/BoundColumn problem

      Hi

      If you add some column at runtime, these have to be loaded at the
      initialization of the page (OnInit method) not in Page_load otherwise the
      page doesn't succeed to load the relative viewstate.

      If you move AddIDColumn(); and AddButtonColumn ();
      into the OnInit method your example it will work

      Ciao
      Giorgio

      "John" <fuzzy333@hotma il.com> ha scritto nel messaggio
      news:1Hhpb.884$ mB5.149626@news 20.bellglobal.c om...[color=blue]
      > The ItemCommand event not getting fired when I add both a BoundColumn and[/color]
      a[color=blue]
      > ButtonColumn to a datagrid. When I add a ButtonColumn by itself,[/color]
      everything[color=blue]
      > works fine, but as soon as I add a BoundColumn, the ItemCommand event
      > doesn't seem to get called.
      >
      > I've been struggling with this for too long now, I'm certain there's
      > something I'm not getting. Here's the relevant code. Thanks in advance!
      >[/color]


        Comment

        • John
          #3
          Re: DataGrid ButtonColumn/BoundColumn problem

          Thanks for your response, you're right this does work. But this brings upon
          more questions! Why do these need to be set in the Init exactly? Also, I
          want to allow the user to show or hide the ButtonColumn, so I store a flag
          in the ViewState to control this. I believe the ViewState is only loaded
          after Init is called. How can I decide to show or hide the ButtonColumn
          then? What's the solution to this problem?

          "Giorgio Parmeggiani" <gipasoft@gipad otnet.com> wrote in message
          news:eAtWc2aoDH A.2592@TK2MSFTN GP10.phx.gbl...[color=blue]
          > Hi
          >
          > If you add some column at runtime, these have to be loaded at the
          > initialization of the page (OnInit method) not in Page_load otherwise the
          > page doesn't succeed to load the relative viewstate.
          >
          > If you move AddIDColumn(); and AddButtonColumn ();
          > into the OnInit method your example it will work
          >
          > Ciao
          > Giorgio
          >
          > "John" <fuzzy333@hotma il.com> ha scritto nel messaggio
          > news:1Hhpb.884$ mB5.149626@news 20.bellglobal.c om...[color=green]
          > > The ItemCommand event not getting fired when I add both a BoundColumn[/color][/color]
          and[color=blue]
          > a[color=green]
          > > ButtonColumn to a datagrid. When I add a ButtonColumn by itself,[/color]
          > everything[color=green]
          > > works fine, but as soon as I add a BoundColumn, the ItemCommand event
          > > doesn't seem to get called.
          > >
          > > I've been struggling with this for too long now, I'm certain there's
          > > something I'm not getting. Here's the relevant code. Thanks in[/color][/color]
          advance![color=blue][color=green]
          > >[/color]
          >
          >[/color]


            Comment

            • Giorgio Parmeggiani
              #4
              Re: DataGrid ButtonColumn/BoundColumn problem

              Hi
              [color=blue]
              > Why do these need to be set in the Init exactly? Also, I
              > want to allow the user to show or hide the ButtonColumn, so I store a flag
              > in the ViewState to control this. I believe the ViewState is only loaded
              > after Init is called. How can I decide to show or hide the ButtonColumn
              > then? What's the solution to this problem?[/color]

              Asp.NET has a well defined Control Life Cycle
              (http://www.15seconds.com/issue/020102.htm)
              so new controls added at runtime at the control collection must be added in
              the OnInit.
              but it is enough that is initialized in the OnInit! you can modify it in
              other methods (for example in the Page_Load)
              For your problem you can:
              1 - Add the datagrdi column on the OnInit
              2 - Hide the column in the Page_load event: datagrid.Column s[0].Visible =
              false.

              Ciao
              Giorgio


                Comment

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