Value of TextBox from a UserControl

[steverbs]

Hi all.

Having a lttle trouble with UserControls. I am wanting to use UserControls to create reusable form elements, such as an address-entry set of TextFields etc. The only trouble is that I have no idea how to access them from a page that contains the control.

For example, if I have a WebForm called UserDetails, which contains an AddressDetails UserControl that is comprised of several text boxes, when the form is submitted, how do I access the values of the text boxes in the AddressDetails control?

Regards.

Stephen.

 

[jen89]

You should have something like this in your declarations on your main page:

Protected WithEvents ctrlpanel As ctrlpanel

In your control panel, try exposing some properties like this:

 Public nName As System.Web.UI.WebControls.TextBox
 Public nAddress As System.Web.UI.WebControls.TextBox

Then in your page load, you can put

nName = txtName
nAddress = txtAddress

On your main page, access the property as

ctrlPanel.nName.text
or
ctrlPanel.nAddress.text

This may not be exact syntax - I usually go the other way around making properties from the main page accessable to the control, so I am winging it here a little. But this hopefully will give you a direction, and intellisense should help out too. And I'll try to answer any questions you might have about this method.

 

[steverbs]

Cheers for the reply.

I think I know where your coming from. I should have also pointed out that I am not adding the UserControls directly; they are being added to the page using placeholders, so that I code it like:

Dim objAddressForm As AddressDetails = LoadControl("AddressDetails.ascx")

Me.phAdminDetails.Controls.Add(objAdminForm)

Now, whenever I try to access the Public properties of the control within the placeholder, I get the error:

'PropertyName is not a member of 'PlaceHolder'.

I have tried accessing the property using:

Dim uclAdminForm As AddressDetails

uclAddressForm = Me.phDetails.FindControl("AddressDetails")

Is there a way to do this using PlaceHolders? I'll have a crack at just adding the UserControl directly to see if I can get away without the PlaceHolder.

Cheers.

Stephen.

 

[steverbs]

OK. Thank you for your solution, it works a treat. I've also just realised that the whole placeholder thing won't work anyways.

Thanks again!

Steve.

 

[jen89]

Great, glad it helped!

 

[steverbs]

One more thing now, if you don't mind. How do I set the properties of the UserControl from the WebForm so that when the UserControl loads, it can populate its text fields with data. I was trying something along the lines of:

(In the WebForm)

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
If (Not Me.IsPostBack) Then
Me.uclAddressDetails.myAddress = Address.firstInstance()

But all I get is a Null Object Reference for the last line, as the control obviously hasn't been instantiated yet. However, whenever I try to instantiate the control using the New satement or LoadControl method, the property doesn't seem to get set.

What am I missing here?

Steve.

 

[jen89]

basically, make any properties that you want to change public in your user control. Then, in the web form, assign those properties a value. For example, if you have

Public nName As System.Web.UI.WebControls.TextBox

in your user control, you can access it through the web form like this:

ctrlPanel.nName

just as if it were any other text box.

So ctrlPanel.nName.text = "John Doe" will put "John Doe" in
your textbox.

"ctrlPanel.nName.visible = false" will hide your text box. ctrlPanel is declared like I did in my previous example. Does this make sense? If it didn't answer your previous question, please rephrase it and I'll try again.

 

[steverbs]

Cheers for the reply.

I've just found out what the problem was. I had been trying as you suggested, to just change the properties via ctrlPanel.property, but it kept coming up with a null reference error. I found that it was because I needed to declare ctrlPanel as Protected instead of Private in the WebForm. Don't quite get why this should've changed anything as I was only acessing ctrlPanel from inside the WebForm anyways.

Thanks again.

Steve.