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MFC, C++: Changing a CButton's icon to a custom icon

Hello,

I have an MFC CButton in an MFC dialog that I'd like to give an icon to, in order to have a proper alpha channel for anti-aliasing, which bitmaps don't seem to offer.

I've set the buttons style to icon in dialog editor (there doesn't seem to be a specific facility for selecting an icon, so I guess it's done in code).

I found this reference on MSDN: http://msdn2.microsoft.com/en-us/library/bd24s672(VS.80).aspx .

This cover's CButton's SetIcon() function.

The following example is given:

myButton.SetIcon( ::LoadIcon(NULL, IDI_QUESTION) );

This works for me - My CButton displays the system question mark icon. However, it does not work with my own icons that are imported into the project. I get the following compiler error:

error C2664: 'LoadIconA' : cannot convert parameter 2 from 'int' to 'LPCSTR'

A generic no conversion found error. Theres no point in doing an explicit typecast either.

What have I done wrong? What have I failed to appreciate?

Regards,
Sternocera

Jaime Olivares

please send the code portion where you load your icons

sternocera

ASKER

Jaime,

I don't load my icons - IDI_QUESTION refers to an icon created with the resource editor.

I don't know how to load icons.
Thanks,
Sternocera

Jaime Olivares

You said:
>>However, it does not work with my own icons that are imported into the project. I get the following compiler error: error C2664: 'LoadIconA' : cannot convert parameter 2 from 'int' to 'LPCSTR'
>>A generic no conversion found error. Theres no point in doing an explicit typecast either.

So I assumed you have tried to load the icon somewhere.

sternocera

ASKER

I've imported an icon(*.ico) into resource editor. I named it something like IDI_MY_ICON.

Thanks

Jaime Olivares

>>I've imported an icon(*.ico) into resource editor. I named it something like IDI_MY_ICON.
this operation doesn't cause the error you mentioned: error C2664: 'LoadIconA' : cannot convert parameter 2 from 'int' to 'LPCSTR'

So, again, please post the line which causes that error message.

sternocera

ASKER

I have!

myButton.SetIcon( ::LoadIcon(NULL, IDI_QUESTION) ); // myButton is a CButton

that's all there is to it.

Jaime Olivares

OK, there are some confusing stuff:
IDI_QUESTION is a system icon. To load it you need:
::LoadIcon(NULL, MAKEINTRESOURCE(IDI_QUESTION))

since LoadIcon expects a string pointer in second argument, MAKEINTRESOURCE convert the integer to the proper type.

Jaime Olivares

To load an icon from your application you will need:
::LoadIcon(::AfxGetResourceHandle(), MAKEINTRESOURCE(IDI_MY_ICON))

sternocera

ASKER

As I said in my original post, I can get it to work with the system icon IDI_QUESTION. This works:
myButton.SetIcon( ::LoadIcon(NULL, IDI_QUESTION) );

However, this does not work:

myButton.SetIcon( ::LoadIcon(NULL, IDI_MY_ICON_FROM_RESOURC_EDITOR) ); // This is the only place this icon appears in the code

It causes the following error message:

error C2664: 'LoadIconA' : cannot convert parameter 2 from 'int' to 'LPCSTR'

I apologise if I was unclear about that,
Regards,
Sternocera

sternocera

ASKER

Jaime,

I don't have access to my windows machine at the moment. I'll let you know how I get on with it tomorrow,

Thanks,
Sternocera

Jaime Olivares

Ok, finally we have the problematic line:
myButton.SetIcon( ::LoadIcon(NULL, IDI_MY_ICON_FROM_RESOURC_EDITOR) );

it should be:
myButton.SetIcon( ::LoadIcon(NULL, MAKEINTRESOURCE(IDI_MY_ICON_FROM_RESOURC_EDITOR)) );

sternocera

ASKER

Jaime,

That doesn't work - the program builds, but my button doesn't display the icon,
Regards,
Sternocera

ASKER CERTIFIED SOLUTION

Jaime Olivares

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sternocera

ASKER

Jaime,

Great, that works!

You talk about memory leaks. If this has caused something to be created on the heap, how can the memory be released?

How can I store in in a variable on the stack so it will be destroyed when it goes out of scope?

Thanks,
Sternocera

Jaime Olivares

You should store as a member in the dialog or window class you are using it.