CString to BYTE array

I have a program that sends a message over a serial port and when I test it with a message like
BYTE Msg[] = "20\r";
everything is ok.

The problem is that I do not want to send "20" everytime.. The message I want to send comes from a CEdit box and I get it with

Code:

---


...
UpdateData(TRUE);               
CString Msg;
m_Felt3.GetWindowText(Msg);
Msg.Format(_T("%s\r"),(LPCTSTR)Msg);               
UpdateData(FALSE);
...

---

How can I change this to be a byte-array like my first example?

I also need to know the number of bytes in my message....

See this thread

Thanks! But I have som problems. Get the error messages:
1>.\OvnAppDlg.cpp(235) : error C2065: '_lpw' : undeclared identifier
1>.\OvnAppDlg.cpp(235) : error C2065: '_convert' : undeclared identifier
1>.\OvnAppDlg.cpp(235) : error C2065: '_acp' : undeclared identifier

I tried the tip in the thread you linked to, to search msdn, but I cant figure it out..
What is wrong? Do i need to include a file?

As I already mentioned in this thread - Search MSDN for "String Conversion Macros"!
And you will find out that all these macros are defined in AFXPRIV.H file. It is what you have to #include.

Besides, your code is incorrect:

Quote:

---

Code:

---

CString Msg;
m_Felt3.GetWindowText(Msg);
Msg.Format(_T("%s\r"),(LPCTSTR)Msg);

---

---

According to MSDN article "CString::Format":

Quote:

---

The call will fail if the string object itself is offered as a parameter to Format. For example, the following code:

Code:

---

CString str = "Some Data";
str.Format("%s%d", str, 123);  // Attention: str is also used in the parameter list.

---

will cause unpredictable results.

---

Try including "atlconv.h" or "afxpriv.h", though I am not sure that is the problem. What line are you getting the error on?

LE: Victor was faster!

Quote:

---

Originally Posted by EoF

Try including "atlconv.h" or "afxpriv.h", though I am not sure that is the problem. What line are you getting the error on?

LE: Victor was faster!

---

Your rigth. It didn't help.. I get the error on this line:
memcpy(barray, T2CA(test), dwPasswordBufferSize);

Quote:

---

Originally Posted by VictorN

Besides, your code is incorrect:According to MSDN article "CString::Format":

---

Do I understand i rigth if I think this is better?

Code:

---

UpdateData(TRUE);               
CString Felt_3_Msg;
m_Felt3.GetWindowText(Felt_3_Msg);               
UpdateData(FALSE);
CString Msg;
Msg.Format(_T("%s\r"),(LPCTSTR)Felt_3_Msg);

---

Yes this code is OK.
However, I'd write it more simple:

Code:

---

CString Msg = Felt_3_Msg + _T('\r');

---

If you don't mind creating an intermediate std:string , you can also do it this way.

Code:

---

    CString cs;
    edit1.GetWindowText(cs);
    std::string ss = cs;
    PBYTE ba = (PBYTE) ss.c_str();

---

Quote:

---

Originally Posted by Sahir

If you don't mind creating an intermediate std:string , you can also do it this way.

---

But how will it work if CString is a UNICODE one?
Will std:string:: operator =() also convert from UNICODE to ANSI? :confused:

Quote:

---

Originally Posted by VictorN

But how will it work if CString is a UNICODE one?
Will std:string:: operator =() also convert from UNICODE to ANSI? :confused:

---

Nobody said anything about UNICODE here. No it will not convert from UNICODE to ANSI .

Will String::Format convert UNICODE to ANSI ? :confused: And have you checked if the above example will work with UNICODE turned on?

This inst that complicated. You made a fundemental MFC error in your first example.

With CStrings, you can not use the same instance using the format method in the format arguments. The results are unpredictable.

IE:

CString Alpha, Beta;

Alpha = " Cat ";
Alpha.Format("%s", Alpha ) ; // WRONG!

Beta.Format("%s", Alpha ); // Right
Alpha = Beta;

To get it into a byte array, just cast it: (const char *)Alpha; Or if you are using the newer StdString derived version, Alpha.c_str();