Custom servercontrol with control-type property. Visibility problem.

Question

User247235378 posted

Hi,

I made own control via inheriting it from TextBox-control. I also made new Label-type property.

Everything seems to go ok but when I try modify referenced Label-control nothing happens.

Example:

Imports System.Web
Imports System.Web.UI
Imports System.ComponentModel
Imports System.Web.UI.WebControls


    <ToolboxData("<{0}:OwnTextbox runat=server></{0}:OwnTextbox>")> _
    <ParseChildren(True)> _
    <PersistChildren(False)> _
    Public Class OwnTextBox
        Inherits TextBox
       

        Private _TitleLabel As Label

        <Category("OwnPropertys")> _
        <PersistenceMode(PersistenceMode.InnerProperty)> _
        Public Property TitleLabel As Label
            Get
                Return _TitleLabel 
            End Get
            Set(ByVal value As Label)
                _TitleLabel = value
            End Set
        End Property
    End Class

End Class

I can select Label-type control on OwnTexbox-property dialog. But when I try modify label text like 

OwnTextBox1.TitleLabel.Text = "yeah"

nothing happens.

I can control it like 

CType(FindControl(OwnTextBox1.TitleLabel.ClientID), Label).Text = "yeah"

and it works but I think this is not best way.

Answer 1

User3866881 posted

Hello OP：）

In my mind I think because everytime when you click something like submit to render the whole page, the label will be automatically crreated again.

I think you can have a try like this——

Imports System.Web
Imports System.Web.UI
Imports System.ComponentModel
Imports System.Web.UI.WebControls


    <ToolboxData("<{0}:OwnTextbox runat=server></{0}:OwnTextbox>")> _
    <ParseChildren(True)> _
    <PersistChildren(False)> _
    Public Class OwnTextBox
        Inherits TextBox 
       

        Private _TitleLabel As Label= New Label

        Public Sub New()

             _TitleLabel.Text = IIf(ViewState("txt")==Nothing,String.Empty,ViewState["txt"].ToString())

        End Sub

       Public Property LabelText As String
       Get
             Return ViewState("txt")
       End Get
        Set(ByVal value As String) 
             ViewState("txt") = value
       End Set
      End Property

             
        <Category("OwnPropertys")> _
        <PersistenceMode(PersistenceMode.InnerProperty)> _
        Public ReadOnly Property TitleLabel As Label
            Get
                Return _TitleLabel 
            End Get 
        End Property
    End Class

Answer 2

User247235378 posted

I think it same use findcontrol then. Meaning is make property which point to Label-control. When textbox raises some error or something it automatically change label's text.

 

Answer 3

User-16411453 posted

You have to assign a ID value to the control, in order to access it. If you don't assign an id, then asp.net will assign an id for it. What you name the control is only reference inside the server control on the server side. ID's are required for javascript to find the control.

I use .ID = [ID] & "_label_control" where the [ID] is the name of the control, for multiple control use.

Then in jquery $('[id*="_label_control"]').text = "Some text";