Custom Control needs ControlToValidate

  • Thread starter Thread starter Steven Nagy
  • Start date Start date
S

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
 
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.
Click to expand...


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

}

HTH
Click to expand...

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:

<asp:Panel 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
 
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?
Click to expand...

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?
Click to expand...

Yes, NamingContainer is the container holding the current control.
How would your example work in this case:

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


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

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
-----------------------------------------
 
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