Re: radiobutton BeforeStateChange ? - C# Discussion Boards

11-Jul-07 22:20

Hi all,

depending on an access level of my app's I want to suppress a statechange of a radiobutton field (without disabling the controls). On a checkbox control I can override the onclick event and use the BeforeStateChange event.
A radiobutton doesn't have such an event.

Who has an idea to do that ?

tnx Frank

fracalifa

Martin#11-Jul-07 22:32

11-Jul-07 22:32

Hello,

You could still override OnClick, and use MouseDown as for the functionality of BeforeStateChange.
Or fire your own event in the OnClick Method.

All the best,

Martin

Luc Pattyn11-Jul-07 23:48

Luc Pattyn

11-Jul-07 23:48

Hi,

dont know about BeforeStateChange event, it is not in my MSDN documentation.

Same MSDN documentation says one should not use RadioButton.OnClick

for RadioButtons you can set AutoCheck=false and do all the Checked logic
yourself.

I consider it bad practice to change the behavior of a standard Control:
a RadioButton (group) should either be enabled and you can operate it normally,
or disabled and you cant operate it at all. For me there is no way in between.

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

Martin#12-Jul-07 0:05

Re: radiobutton BeforeStateChange ? [modified]

12-Jul-07 0:05

Hello Luc,

Luc Pattyn wrote:
I consider it bad practice to change the behavior of a standard Control

I don't agree in this point, as I often manipulat standard Controls for my needs.
As "overriding" gives me the chance to change the behavior of controls in the way my "customer" is used to it from machines my company delivered years ago.
And I think the point is, as some people (including me) are not doing WEB Applications or standard Windows Application for PC's, your statement doesn't fit for all.

Smile | :)

All the best,

Martin

fracalifa12-Jul-07 0:32

12-Jul-07 0:32

Hi Luc,

you are right, sorry, I override the onclick event and created an own event called checkBeforeChange like this

protected override void OnClick(EventArgs e)    <br />
{       <br />
        if(this.BeforeStateChange != null)<br />
        {<br />
            this.BeforeStateChange(this, ref cancelStateChg);<br />
        }<br />
        if(this.cancelStateChg)<br />
        {           <br />
            this.Checked = !this.Checked;<br />
        }       <br />
        base.OnClick (e);<br />
}<br />

this code is working on a checkbox, but not on a radiobutton.

I would use enable=true/false but the bad is the color change to gray. If I could prevent the colorchange, everything would be fine.

Frank

-- modified at 6:37 Thursday 12th July, 2007

Luc Pattyn12-Jul-07 0:36

Luc Pattyn

12-Jul-07 0:36

I understand that, but the basic point is a Control that is disabled MUST
look different; if it did not, the user would manipulate it unknowingly,
and then complain it does not work as expected.

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

fracalifa12-Jul-07 0:40

12-Jul-07 0:40

Hi luc

a disabled control should look different, but in a way I can decide of, and not in the way MS do.

tnx

Luc Pattyn12-Jul-07 1:44

Luc Pattyn

12-Jul-07 1:44

Standards are fantastic. Everyone should have one.

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

ruanr12-Jul-07 0:23

ruanr

12-Jul-07 0:23

A simple solution is to intercept checkchanged, and set the button back to checked if it is not checked.

Not the most elegant though Smile | :)

Martin#12-Jul-07 0:39

12-Jul-07 0:39

Hello,

fracalifa wrote per e-mail:
Hi Martin,
tnx, that works, but how can I prevent the statechange of the radiobutton ? Is there a cancel option which I can use for?
Tnx Frank [confused]

I haven't even found "statechange", is it .NET>1.1?

P.S.: please respond in the forum, cause I'm not answering per e-mail!

All the best,

Martin

fracalifa12-Jul-07 1:07

12-Jul-07 1:07

Hi Martin,

other than a checkbox a radiobutton is a group of controls. With the checkbox I can do suppressing the toggle of the state, with the radiobutton(s) I can do not.My wish is to prevent the change of state from uncheched to checked when clicking on it, that's all (without enable = false).

tnx Frank

Martin#12-Jul-07 1:11

12-Jul-07 1:11

But haven't you allready told the solution with overriding the OnClick.
I tested it with an inherited (from RadioButton) control.

private bool _disable = false;
public bool Disable
{
    get
    {
        return _disable;
    }
    set
    {
        if(value!=_disable)
        {
            _disable = value;
        }
    }
}

protected override void OnClick(EventArgs e)
{
    if(!Disable)
        base.OnClick (e);
}

Works well for me.

All the best,

Martin

fracalifa12-Jul-07 1:18

12-Jul-07 1:18

Yes, that's it,

my fault was the calling of the base class even when it is disabled.

tnx

Martin#12-Jul-07 1:40

12-Jul-07 1:40

Glad I could help!
You are wellcome!

All the best,

Martin

creating a custom editor

KaleoDev11-Jul-07 21:38

KaleoDev

11-Jul-07 21:38

Hello there,

I have been asked to create a design surface where you can drag and drop controls onto this surface and it will automatically generate the XAML code , now the problem is i have never done this before, so if there is anyone who can help me with this it would be greatly appreciated.

thanks in advance

Bekjong12-Jul-07 0:03

Bekjong

12-Jul-07 0:03

How about buying Microsoft Expression Blend?

Standards are great! Everybody should have one!

KaleoDev12-Jul-07 1:52

KaleoDev

12-Jul-07 1:52

thanks for the reply,
im actually trying to create a custom IDE like VS that i can drag and drop controls onto a surface and the XAML code for those controls will be generated automatically,

Bekjong12-Jul-07 1:59

Bekjong

12-Jul-07 1:59

Well yes, that's what Expression Blend does. It'll probably be cheaper to buy it than putting in vast amounts of time and trouble to create something similar.

Standards are great! Everybody should have one!