Custom Control needs ControlToValidate

[Steven Nagy]

Hi all,

I have a custom user control in an ASP.NET app (.NET 2.0).
This control needs a public property called "ControlToValidate" which
accepts strings.
I need to be able to declare it much as you would with a validator
control, like this:


What is important is that my custom control is able to get the
ClientID of the control passed in.
The above code would only pass "myTextbox" as a string, not the actual
textbox control.

I am curious how to do this. If I were to user a
RequiredFieldValidator, I could set ControlToValidate as per my above
usage. So its this behaviour I want to replicate.

I used reflector to view the RequiredFieldValidator's implementation
of ControlToValidate and it simply inherits from BaseValidator. I
tried using this inheritance also, but kept getting compile errors
because BaseValidator ultimately inherits from Control, not
UserControl (sif that should matter).

Googling brought me no love. I suspect there is an attribute I need to
use, possibly a TypeConverter somewhere, just not sure how.

Any help would be greatly appreciated.

Cheers,
Steven

 

[MasterGaurav \(www.edujini-labs.com\)]

What is important is that my custom control is able to get the

ClientID of the control passed in.
The above code would only pass "myTextbox" as a string, not the actual
textbox control.

Control ctrl = base.NamingContainer.FindControl(this.ControlToValidate);
if(ctrl != null)
{
TextBox box = ctrl as TextBox;
if(box != null)
{
string value = box.Text;
}
}


HTH

--
Happy Hacking,
Gaurav Vaish | www.mastergaurav.com
www.edujini-labs.com
http://eduzine.edujini-labs.com
-----------------------------------------

 

[Steven Nagy]

Control ctrl = base.NamingContainer.FindControl(this.ControlToValidate);
if(ctrl != null)
{
TextBox box = ctrl as TextBox;
if(box != null)
{
string value = box.Text;
}

}

HTH

Ok so in your example, the string that gets passed is something like
"txtUserName".
However, at runtime the textbox id is actually
"MainForm_SomeSubConrol_txtUserName".
Will this code still work 100% if the form has two "txtUserName"
textboxes?
I haven't used "base.NamingContainer" before; is this the container
that is holding the current control?
How would your example work in this case:

<aspanel id="pnlSomeStuff" runat="server">
<asp:Textbox id="txtUserName" runat="server" />

.... because the textbox is not in the same scope as the custom
control.

I appreciate your help,
Steven Nagy

 

[Steven Nagy]

Anyone?

 

[MasterGaurav \(www.edujini-labs.com\)]

Ok so in your example, the string that gets passed is something like

"txtUserName".
However, at runtime the textbox id is actually
"MainForm_SomeSubConrol_txtUserName".
Will this code still work 100% if the form has two "txtUserName"
textboxes?

I missed out your "Anyone?" posting...

The textbox-ID is never "MainForm_SomeSubControl_txtUserName". It is the
value of "ClientID".

I haven't used "base.NamingContainer" before; is this the container
that is holding the current control?

Yes, NamingContainer is the container holding the current control.

How would your example work in this case:

<aspanel id="pnlSomeStuff" runat="server">
<asp:Textbox id="txtUserName" runat="server" />


... because the textbox is not in the same scope as the custom
control.

In this case, you can use (from inside uc1:MyControl):

this.Page.FindControl("txtUserName")

Note that UserControl also implements INamingContainer. So, for the
uc1-control, the lookup would be within MyControl since that's the
NamingContainer for the control.

Btw, for all these complex-resolving issues, I would recommend that you
design a WebControl rather than UserControl (because UserControl becomes the
naming container).

Anyway, Page.FindControl("...") should give you the expected results.


--
Happy Hacking,
Gaurav Vaish | www.mastergaurav.com
www.edujini-labs.com
http://eduzine.edujini-labs.com
-----------------------------------------