Validating dynamically created textboxes

I am dynamically creating textboxes and for each textbox a custom validator control.
How do I link the validator control to the textbox so it can be Validated.

Thanks

Each Validator has a ControlToValidate property, doesn't it?

It does but with the custom validator control you cannot reference it in code as it is not a physical control on the webform.
I have also not managed to linke any dynamically created validation control to a dynamically created textbox. For me it just doesn't work, so I am hoping others have had better success and can tell me how.

I'll look into this when I get into work, can you show all the relevant code you have so far?

Example:

VB Code:

Public myTextBox As TextBox
Public myValidator As CustomValidator
 
myTextBox = New TextBox
 
myValidator = New CustomValidator
myValidator.ControlToValidate = myTextBox.ID

A dynamically created textbox does not have an ID until it is added to its container.

An easily missed clarification is - you have to set the ControlToValidate property only after the control you want to validate has been added to its container - otherwise it does have an ID, and you will get the infamous 'ControlToValidate cannot be set to nothing' error.

VB Code:

Public myTextBox As TextBox
Public myValidator As CustomValidator
 
myTextBox = New TextBox
 
myValidator = New CustomValidator
'TEXTBOX must be added to its container first
Controls.Add(myTextBox)
myValidator.ControlToValidate = myTextBox.ID

I am not at work at the moment but the way I am doing it is this.
This code is done from memory so there may be minor syntactic errors.

VB Code:

dim tr as new tablerow
        dim tc as new tablecell
 
        dim tb as new textbox
        tb.id = "txt1"
        tc.contols.add(tb)
        tr.cells.add(tc)
 
        tc=new tablecell
 
        dim cv as new customvalidator
        cv.controltovalidate = "txt1"
        tc.controls.add (cv)
 
        tr.cells.add(tc)
 
        table1.rows.add(tr)

As you can see I am creating an new textbox, giving it an ID then adding it to the table web control.

I wonder if the textbox retains the id I specify? I am presuming it does but it would be good to check that out.

Do you think the fact the controls are contained within a table makes any difference? I wouldn't have thought so.

Specificying an id probably won't make a difference. The framework normally appends the name of the control, or increments from control collection.

For instance, if the control was added to a panel...

pnl0_txt1

would be the clientid seen on the client-side.

Anyway, you just have to be sure to set the controlToValidate property after the controls have been added to the parent container - without which, how could the framework possibly know how to identify the controls? The framework must use the parent_child naming scheme mentioned above for postback and viewstate, so you can only accurately assign it after it has been added to the container.

The below code is in C#, but I think you can convert it to VB easily enough since its mostly .Net methods except the declarations.

Code:

---

private void Page_Load(object sender, System.EventArgs e)
{
CustomValidator validator;
Table table;
TableRow tr;
TableCell tc;
TextBox textbox;

textbox = new TextBox();                       
validator = new CustomValidator();


tr = new TableRow();

tc = new TableCell();
tc.Controls.Add(textbox);
tr.Cells.Add(tc);

tc = new TableCell();
tc.Controls.Add(validator);
tr.Cells.Add(tc);

table = new Table();           
table.Rows.Add(tr);
//following line for this demonstration.. adds controls to the document.
Page.Controls[1].Controls.Add(table);

//now that the controls have been added to the parent
//container, you can properly assign the property. It is
//only after the controls have been added, can the framework
//distinguish the naming scheme.

validator.ControlToValidate = textbox.ClientID;
}

---

Thanks for all your help, I am getting closer now but there are a few things I need to iron out.

I have a web form with a table and a button (web controls).
This is the code on the form.

VB Code:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
 
 
        '****************************************************************
        '*
        '
        Dim tr As New TableRow
        Dim cell As New TableCell
 
        Dim t As New TextBox
 
        cell.Controls.Add(t)
        tr.Cells.Add(cell)
 
        cell = New TableCell
        cell.Text = "hello?"
        tr.Cells.Add(cell)
 
        cell = New TableCell
        Dim p As New CustomValidator
        cell.Controls.Add(p)
        tr.Cells.Add(cell)
 
        Table1.Rows.Add(tr)
 
        Table1.GridLines = GridLines.Both
 
        p.ControlToValidate = t.ClientID
 
        Response.Write(t.ClientID)
        Response.Write(p.ControlToValidate)
        Response.Write(p.ClientID)
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        'Property does not exist
        'table1.Rows(0).Cells(2).Controls(0).isvalid
 
        'This does not work
        Dim c As New CustomValidator
        c = DirectCast(Table1.Rows(0).Cells(2).Controls(0), CustomValidator)
 
        Dim t As New TextBox
        t = DirectCast(Table1.Rows(0).Cells(0).Controls(0), TextBox)
 
        If t.Text <> "qwerty" Then
            c.IsValid = False
        Else
            c.IsValid = True
        End If
    End Sub

Now my problem is how to reference the custom validator so I can set the IsValid property to true/false. I can't do it this way

VB Code:

table1.Rows(0).Cells(2).Controls(0).isvalid

as the property does not exist, and trying it the other way above just does not work.

Another interesting thing is (Which is OK for me because I want a CustomValidator control) if you change the validator control to a requiredfieldvalidator control the page will not postback when you click the button. At least that is what happened to me.

So the question remains:
How can I set the IsValid property of a customValidator control created dynamically when a button is pressed?

I have attached the webform to save you copying and pasting code.