VC, Subclassing controls

Scott Schaffne
#1 / 3

Subclassing controls

I have read some solutions that said you should subclass a control in order
to do certain things such as intercept messages. What I was wondering was
how to you do this.
For example I was told in order to stop a text box from highlighting the
text when it receives focus I should subclass it and intercept the
selection message. What is the syntax to subclass this text box, and how do
I intercept the messages sent to it?
Please be detailed and technical with the answer, I'm up to it.
Thank you very much,

Sat, 16 Oct 1999 03:00:00 GMT

Donald C. Ason
#2 / 3

Subclassing controls

: I have read some solutions that said you should subclass a control in order
: to do certain things such as intercept messages. What I was wondering was
: how to you do this.
: For example I was told in order to stop a text box from highlighting the
: text when it receives focus I should subclass it and intercept the
: selection message. What is the syntax to subclass this text box, and how do
: I intercept the messages sent to it?
: Please be detailed and technical with the answer, I'm up to it.

It's quite simple. If you have a control, i.e. an edit control,
then create a class derived from a CEdit (if using MFC). Then map
a handler for the message you want to intercept.

Now, here is how you subclass the control. Let's say you have a
control with id IDC_EDIT1. Then do this:

CMyEditClass m_edit1; // declared somewhere.

m_edit1.SubclassDlgItem(IDC_EDIT1, this); // this = parent window.

I told you it was trivial :).

: Thank you very much,

Good luck,
--
Donald
**************************************************************
* I got a Mantis in my Pantis. *
* Professor, pathology is limited, it's pathetic! *
* -- Mystery Science Theater 3000 *
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*Samples:ftp://ftp.hpc.uh.edu/pub/donald *
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Sat, 16 Oct 1999 03:00:00 GMT

Andy Y
#3 / 3

Subclassing controls

Quote:

>: I have read some solutions that said you should subclass a control in order
>: to do certain things such as intercept messages. What I was wondering was
>: how to you do this.
>: For example I was told in order to stop a text box from highlighting the
>: text when it receives focus I should subclass it and intercept the
>: selection message. What is the syntax to subclass this text box, and how do
>: I intercept the messages sent to it?
>: Please be detailed and technical with the answer, I'm up to it.

>It's quite simple. If you have a control, i.e. an edit control,
>then create a class derived from a CEdit (if using MFC). Then map
>a handler for the message you want to intercept.

>Now, here is how you subclass the control. Let's say you have a
>control with id IDC_EDIT1. Then do this:

> CMyEditClass m_edit1; // declared somewhere.

> m_edit1.SubclassDlgItem(IDC_EDIT1, this); // this = parent window.

>I told you it was trivial :).

Another way to do this is to use DDX_Control() in DoDataExchange(). This also
subclasses the control.

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Sat, 16 Oct 1999 03:00:00 GMT