Question

I have asp:panel with some controls, the mark-up as below

<asp:panel id="panel1" runat="server">
    <asp:Label runat="server" Text="aaaa"></asp:Label>
    <asp:Label runat="server" Text="bbbb"></asp:Label>
    <asp:Label runat="server" Text="cccc"></asp:Label>
    <asp:TextBox runat="server" ID="txt1"></asp:TextBox>
    <asp:TextBox runat="server" ID="txt2"></asp:TextBox>
    <asp:ImageButton ID="ibtn1" runat="server"/>
    <asp:ImageButton ID="ibtn2" runat="server"/>
</asp:panel>

Now I want to disable all the controls, but enabling ibtn1 and ibtn2

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
    panel1.Enabled = False
End Sub

Protected Sub Page_PreRender(sender As Object, e As System.EventArgs) Handles Me.PreRender
    ibtn1.Enabled = True
    ibtn2.Enabled = True
End Sub

All of the controls are disabled, that’s great, but not for ibtn1 and ibtn 2.

Then, I have tried this method instead

Public Sub lDisableAllChildControls(ByRef p As WebControl)
    For Each c As System.Web.UI.WebControls.WebControl In p.Controls
        c.Enabled = False
        'recurse
        lDisableAllChildControls(c)
    Next
End Sub

but it gave me this error:

Unable to cast object of type ‘System.Web.UI.LiteralControl’ to type
‘System.Web.UI.WebControls.WebControl’

Does anyone has any idea to make this work? Thanks!

Answer 1

you replace with Control, because your label is litteral

 For Each c As System.Web.UI.Control.Control In p.Controls

 Next