Control.Controls bug? Control's child controls missing at the run time.

7 Dec 2005 9:56 PM

sinelnikov.andrei

Hello,

..NET 1.1/VB.NET:

I have a custom web control

    Public Class DatePicker
    Inherits Control
    Implements INamingContainer

In the CreateChildControls I adding some controls to it:

    Protected Overrides Sub CreateChildControls()
        placeJavascript()
        MyBase.Controls.Add(New LiteralControl("<table
class='Calendar'><tr><td>"))
        Dim txtTextBox As New System.Web.UI.WebControls.TextBox

        With txtTextBox
            If Len(m_ControlCssClass) > 0 Then
                .CssClass = m_ControlCssClass
            End If
            If Not (m_text = "") Then
                .Text = m_text
            End If
            If Not (m_Css = "") Then
                .CssClass = m_Css
            End If
            .ID = "foo"
            .Width = Unit.Pixel(80)
            .MaxLength = Me.DateType.Length
        End With

        MyBase.Controls.Add(txtTextBox)
        MyBase.Controls.Add(New LiteralControl( _
            "<img border='0' class='ImgNoSpace' alt='Calendar' " & _
                "src='" & imgDirectory + m_calendar & "' " & _
                "onclick=""javascript:popUpCalendar(document.all." &
Me.ClientID & "_foo,document.all." & _
                Me.ClientID & "_foo, '" & m_DateType & "');"">"))
        MyBase.Controls.Add(New LiteralControl("</td></tr></table>"))
    End Sub

Now, then I trying to do For Each ctl As Control In myControl.Controls
on my page:

    Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
        ' Call base load before we do any work at this level
        MyBase.OnLoad(e)

        dpFrom.ValidatingControlClientID = btnSearch.ClientID
        dpThrough.ValidatingControlClientID = btnSearch.ClientID

        For Each ctl As Control In dpFrom.Controls
            If TypeOf ctl Is TextBox Then
                dpThrough.SecondDateControlClientID = ctl.ClientID
            End If
        Next

        For Each ctl As Control In dpThrough.Controls
            If TypeOf ctl Is TextBox Then
                dpFrom.SecondDateControlClientID = ctl.ClientID
            End If
        Next

    End Sub

I am getting nothing...

So, if I set the breakpoint on the For Each ctl As Control In
dpFrom.Controls and QuickWatch (or just Watch) dpFrom.Controls - I will

see Count = 0.

Now - interesting part: If I QuickWatch (or just Watch) just dpFrom and

will expand Controls property - I will see Count = 4.

And after that - if I QuickWatch (or just Watch) dpFrom.Controls - I
will see Count = 4.

I beleive that that is a bug.

So, how I can get my control's child controls on the page? Should I do
something differently then I adding child controls in my web control?

Help! :-)

8 Dec 2005 6:46 AM

Teemu Keiski

Hi,

CreateChildControls will not be called unless something in your control
invokes either FindControl (normally on postbacking control this is
initiated on postback) or your control passes to PreRender phase, where
controls are created automatically. E.g something should signal creating
them.

You can get accessing the Controls collection to cause EnsureChildControls
to be called if youy override Controls property

Public Overrides Controls As ControlsCollection
    Get
        EnsureChildControls()
        Return MyBAse.Controls
    End Get
End Property

With this approach child controls will be created when you loop though the
collection.

--
Teemu Keiski
ASP.NET MVP, AspInsider
Finland, EU
http://blogs.aspadvice.com/joteke

<sinelnikov.and***@gmail.com> wrote in message

Show quoteHide quote

news:1133992573.197913.301030@f14g2000cwb.googlegroups.com...
> Hello,
>
>
> .NET 1.1/VB.NET:
>
>
> I have a custom web control
>
>
>    Public Class DatePicker
>    Inherits Control
>    Implements INamingContainer
>
>
> In the CreateChildControls I adding some controls to it:
>
>
>    Protected Overrides Sub CreateChildControls()
>        placeJavascript()
>        MyBase.Controls.Add(New LiteralControl("<table
> class='Calendar'><tr><td>"))
>        Dim txtTextBox As New System.Web.UI.WebControls.TextBox
>
>
>        With txtTextBox
>            If Len(m_ControlCssClass) > 0 Then
>                .CssClass = m_ControlCssClass
>            End If
>            If Not (m_text = "") Then
>                .Text = m_text
>            End If
>            If Not (m_Css = "") Then
>                .CssClass = m_Css
>            End If
>            .ID = "foo"
>            .Width = Unit.Pixel(80)
>            .MaxLength = Me.DateType.Length
>        End With
>
>
>        MyBase.Controls.Add(txtTextBox)
>        MyBase.Controls.Add(New LiteralControl( _
>            "<img border='0' class='ImgNoSpace' alt='Calendar' " & _
>                "src='" & imgDirectory + m_calendar & "' " & _
>                "onclick=""javascript:popUpCalendar(document.all." &
> Me.ClientID & "_foo,document.all." & _
>                Me.ClientID & "_foo, '" & m_DateType & "');"">"))
>        MyBase.Controls.Add(New LiteralControl("</td></tr></table>"))
>    End Sub
>
>
> Now, then I trying to do For Each ctl As Control In myControl.Controls
> on my page:
>
>
>    Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
>        ' Call base load before we do any work at this level
>        MyBase.OnLoad(e)
>
>
>        dpFrom.ValidatingControlClientID = btnSearch.ClientID
>        dpThrough.ValidatingControlClientID = btnSearch.ClientID
>
>
>        For Each ctl As Control In dpFrom.Controls
>            If TypeOf ctl Is TextBox Then
>                dpThrough.SecondDateControlClientID = ctl.ClientID
>            End If
>        Next
>
>
>        For Each ctl As Control In dpThrough.Controls
>            If TypeOf ctl Is TextBox Then
>                dpFrom.SecondDateControlClientID = ctl.ClientID
>            End If
>        Next
>
>
>    End Sub
>
>
> I am getting nothing...
>
>
> So, if I set the breakpoint on the For Each ctl As Control In
> dpFrom.Controls and QuickWatch (or just Watch) dpFrom.Controls - I will
>
> see Count = 0.
>
>
> Now - interesting part: If I QuickWatch (or just Watch) just dpFrom and
>
> will expand Controls property - I will see Count = 4.
>
>
> And after that - if I QuickWatch (or just Watch) dpFrom.Controls - I
> will see Count = 4.
>
>
> I beleive that that is a bug.
>
>
> So, how I can get my control's child controls on the page? Should I do
> something differently then I adding child controls in my web control?
>
>
> Help! :-)
>