How to set accented characters on a Button in MFC application

Question

How to set accented characters on a Button in MFC application

SG 35

Hi,
I'm developping a little MFC project to drive an Arduino board.
I try to change caption in a Button but accented characters (french) are displayed as garbage.

My code:

void CMFCArduinoDlg::OnBnClickedButtonConnecter()
{
	btnConnecter.SetWindowTextW(L"Connecté");
}

The problem is I expected "Connecté" but it appears "ConnectÃ©"
The function SetWindowTextW expects a LPCTSTR.

I think the problem is because I give a const wchar_t (L prefix), but I didn't find any other solution to initialise a LPCTSTR.

I think the problem is here because when I design my dialog, the accented text passed to the button in the dialog editor is well displayed when I run the app. The garbage text comes when I call SetWindowTextW (idem with SetWindowText).

For information, Locale is set to French in resource file:

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_FRA)
LANGUAGE LANG_FRENCH, SUBLANG_FRENCH

The charset in my project properties is set to Unicode

Thanks for reading, I hope to find an issue.

David Lowndes 2,615 Reputation points MVP

2023-10-17T20:24:56.3966667+00:00

The characters you're seeing appear to be a UTF-8 conversion of the Windows Unicode string. If you start from a new MFC dialog project, can you reproduce the issue (as I can't)?
SG 35 Reputation points

2023-10-17T22:30:39.4733333+00:00

Yes, I can reproduce the issue from a new project and differents computers too.

According to this UTF-8 Character Debug Tool (link below), it seems the problem is being caused by UTF-8 bytes being interpreted as Windows-1252 (or ISO 8859-1) bytes

Source: https://www.i18nqa.com/debug/utf8-debug.html

As it works well when I start a new MFC dialog based project, add a single button and set the caption propertie in the dialog designer, everything let me think the problem appears in the function SetWindowsTextW.
RLWA32 48,821 Reputation points

2023-10-17T22:58:29.3266667+00:00

If the application is a Unicode build, Unicode string literals are being used and the Windows API "W" functions are called under the hood by MFC there's no reason that I can see for utf-8 to be involved. Seems to me that some piece of the puzzle is missing.
David Lowndes 2,615 Reputation points MVP

2023-10-17T23:03:12.72+00:00

I tested using SetWindowTextW - and don't have the problem.
If you debug your program, what does the debugger show for the string if you step into the SetWindowsTextW call?
Here's what I see:
SG 35 Reputation points

2023-10-18T07:45:00.3666667+00:00

I didn't found the file where the SetWindowText definition is. If I put a breakpoint when I call the function (below) it goes in the message loop. In which file it is ? The only occurence I found is the declaration in afxwin.h

But hovering directly gives the right text. It looks like we are very close :)
SG 35 Reputation points

2023-10-18T07:52:16.04+00:00

If the application is a Unicode build, Unicode string literals are being used and the Windows API "W" functions are called under the hood by MFC there's no reason that I can see for utf-8 to be involved. Seems to me that some piece of the puzzle is missing.

I thought about that but the same issue appears on 3 computers. Could it be a bug on this version ? I will try with an earlier versions like VS 2019 or VC++ express 2005 to see if I can reproduce the issue.
It doesn't matter because I will be the only one to use this application and it can stay in english but I need to know why it doesn't work
David Lowndes 2,615 Reputation points MVP

2023-10-18T08:18:46.74+00:00

When you're at that line where you call SetWindowTextW, right click and use Step Into Specific.
David Lowndes 2,615 Reputation points MVP

2023-10-18T08:21:03.11+00:00

The fact that the issue occurs on any computer you try points to there being something odd about your code that we're not yet aware of - something is doing a UTF-16->UTF-8 conversion and outputting that.
SG 35 Reputation points

2023-10-18T10:19:34.7933333+00:00

Try to use the “Save As” command from FILE menu for the source file that contains L"Connecté", select the “Save with Encoding” from dropdown menu of Save button, select the “Unicode” or “Unicode (UTF-8 with signature)” encoding. Do not select the “Unicode (UTF-8 without signature)” encoding.

Great, it works !! I guess it's a configuration issue in VS general configuration. I'm going to find it in VC options

The fact that the issue occurs on any computer you try points to there being something odd about your code that we're not yet aware of - something is doing a UTF-16->UTF-8 conversion and outputting that.

Right, by default the files are saved as Unicode(UTF-8 without signature). It's definitely a charset issue somewhere. Glad to know it's not in the code itself.
SG 35 Reputation points

2023-10-18T10:43:36.2733333+00:00

I tested using SetWindowTextW - and don't have the problem.
If you debug your program, what does the debugger show for the string if you step into the SetWindowsTextW call?
Here's what I see:

Then it's working after saving with UTF-8 with signature but when I Step Into Specific I have chinese characters:

And the result is what I expect:

Strange behavior. I'll head on this issue, it's interresting to know why
RLWA32 48,821 Reputation points

2023-10-18T11:15:08.66+00:00

Are your systems configured to use utf-8 for non-Unicode programs?
RLWA32 48,821 Reputation points

2023-10-18T13:25:01.8766667+00:00

I did notice an interesting behind the scenes behavior from VS2022 on Win 10 22H2. I created a new MFC dialog-based project and closed it. Then I opened a source file with notepad which identified the encoding as UTF-8. I re-opened the project and added the call to SetWindowText with the UNICODE string containing the "é" character. Upon building and executing the button caption was changed as expected. However, when I examined the source file again with notepad it identified the encoding as ANSI not UTF-8. Apparently, when VS2022 saved the source file it changed the encoding on its own!
Viorel 121.6K Reputation points

2023-10-18T13:47:05.5533333+00:00

I guess it's a configuration issue in VS general configuration. I'm going to find it in VC options

To use the correct encoding in case of UTF-8 files that do not include the signature, try to add the “/source-charset:utf-8” compiler option for the whole project and all configurations (https://learn.microsoft.com/en-us/cpp/build/reference/source-charset-set-source-character-set), or just for required files (if there are no conflicts with Precompiled Headers). (It is probably better to use files with signature).
Minxin Yu 13,501 Reputation points Microsoft External Staff

2023-10-19T01:26:23.5066667+00:00

Hi, @SG

Glad to know Viorel's solution works for you! Please consider accepting the answer to change this thread's status to Answered. It will also help others to solve the similar issue.

Accepted answer

1 additional answer

Your answer

David Lowndes 2,615 Reputation points MVP

2023-10-17T20:24:56.3966667+00:00

The characters you're seeing appear to be a UTF-8 conversion of the Windows Unicode string. If you start from a new MFC dialog project, can you reproduce the issue (as I can't)?
SG 35 Reputation points

2023-10-17T22:30:39.4733333+00:00

Yes, I can reproduce the issue from a new project and differents computers too.

According to this UTF-8 Character Debug Tool (link below), it seems the problem is being caused by UTF-8 bytes being interpreted as Windows-1252 (or ISO 8859-1) bytes

Source: https://www.i18nqa.com/debug/utf8-debug.html

As it works well when I start a new MFC dialog based project, add a single button and set the caption propertie in the dialog designer, everything let me think the problem appears in the function SetWindowsTextW.
RLWA32 48,821 Reputation points

2023-10-17T22:58:29.3266667+00:00

If the application is a Unicode build, Unicode string literals are being used and the Windows API "W" functions are called under the hood by MFC there's no reason that I can see for utf-8 to be involved. Seems to me that some piece of the puzzle is missing.
David Lowndes 2,615 Reputation points MVP

2023-10-17T23:03:12.72+00:00

I tested using SetWindowTextW - and don't have the problem.
If you debug your program, what does the debugger show for the string if you step into the SetWindowsTextW call?
Here's what I see:
SG 35 Reputation points

2023-10-18T07:45:00.3666667+00:00

I didn't found the file where the SetWindowText definition is. If I put a breakpoint when I call the function (below) it goes in the message loop. In which file it is ? The only occurence I found is the declaration in afxwin.h

But hovering directly gives the right text. It looks like we are very close :)
SG 35 Reputation points

2023-10-18T07:52:16.04+00:00

If the application is a Unicode build, Unicode string literals are being used and the Windows API "W" functions are called under the hood by MFC there's no reason that I can see for utf-8 to be involved. Seems to me that some piece of the puzzle is missing.

I thought about that but the same issue appears on 3 computers. Could it be a bug on this version ? I will try with an earlier versions like VS 2019 or VC++ express 2005 to see if I can reproduce the issue.
It doesn't matter because I will be the only one to use this application and it can stay in english but I need to know why it doesn't work
David Lowndes 2,615 Reputation points MVP

2023-10-18T08:18:46.74+00:00

When you're at that line where you call SetWindowTextW, right click and use Step Into Specific.
David Lowndes 2,615 Reputation points MVP

2023-10-18T08:21:03.11+00:00

The fact that the issue occurs on any computer you try points to there being something odd about your code that we're not yet aware of - something is doing a UTF-16->UTF-8 conversion and outputting that.
SG 35 Reputation points

2023-10-18T10:19:34.7933333+00:00

Try to use the “Save As” command from FILE menu for the source file that contains L"Connecté", select the “Save with Encoding” from dropdown menu of Save button, select the “Unicode” or “Unicode (UTF-8 with signature)” encoding. Do not select the “Unicode (UTF-8 without signature)” encoding.

Great, it works !! I guess it's a configuration issue in VS general configuration. I'm going to find it in VC options

The fact that the issue occurs on any computer you try points to there being something odd about your code that we're not yet aware of - something is doing a UTF-16->UTF-8 conversion and outputting that.

Right, by default the files are saved as Unicode(UTF-8 without signature). It's definitely a charset issue somewhere. Glad to know it's not in the code itself.
SG 35 Reputation points

2023-10-18T10:43:36.2733333+00:00

I tested using SetWindowTextW - and don't have the problem.
If you debug your program, what does the debugger show for the string if you step into the SetWindowsTextW call?
Here's what I see:

Then it's working after saving with UTF-8 with signature but when I Step Into Specific I have chinese characters:

And the result is what I expect:

Strange behavior. I'll head on this issue, it's interresting to know why
RLWA32 48,821 Reputation points

2023-10-18T11:15:08.66+00:00

Are your systems configured to use utf-8 for non-Unicode programs?
RLWA32 48,821 Reputation points

2023-10-18T13:25:01.8766667+00:00

I did notice an interesting behind the scenes behavior from VS2022 on Win 10 22H2. I created a new MFC dialog-based project and closed it. Then I opened a source file with notepad which identified the encoding as UTF-8. I re-opened the project and added the call to SetWindowText with the UNICODE string containing the "é" character. Upon building and executing the button caption was changed as expected. However, when I examined the source file again with notepad it identified the encoding as ANSI not UTF-8. Apparently, when VS2022 saved the source file it changed the encoding on its own!
Viorel 121.6K Reputation points

2023-10-18T13:47:05.5533333+00:00

I guess it's a configuration issue in VS general configuration. I'm going to find it in VC options

To use the correct encoding in case of UTF-8 files that do not include the signature, try to add the “/source-charset:utf-8” compiler option for the whole project and all configurations (https://learn.microsoft.com/en-us/cpp/build/reference/source-charset-set-source-character-set), or just for required files (if there are no conflicts with Precompiled Headers). (It is probably better to use files with signature).
Minxin Yu 13,501 Reputation points Microsoft External Staff

2023-10-19T01:26:23.5066667+00:00

Hi, @SG

Glad to know Viorel's solution works for you! Please consider accepting the answer to change this thread's status to Answered. It will also help others to solve the similar issue.

Answer 1

Viorel 121.6K

Try to use the “Save As” command from FILE menu for the source file that contains L"Connecté", select the “Save with Encoding” from dropdown menu of Save button, select the “Unicode” or “Unicode (UTF-8 with signature)” encoding. Do not select the “Unicode (UTF-8 without signature)” encoding.

Answer 2

SG 35

Are your systems configured to use utf-8 for non-Unicode programs?

No, it's unchecked, it's one of the first things I looked for. I think the problem is with VC configuration

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How to set accented characters on a Button in MFC application

1 additional answer

Your answer