MFC example c-CodePudding

Really don't understand c + +, this example how to do!

Char * _stdcall stringCombo (char * str1, char * str2)
{
Char * str3="upstring=";

Char * str4="& amp; UpFullFileName=";

Char combo=new char []
Sprintf_s (combo, sizeof (combo), "% s, % s, % s, % s", str1, str2, str3, str4);

Return combo
}

//combo need to turn the str1 str2, str3, str4 pieced together, can you tell me how?

Not write their own examples, could you please tell me what to do, with c + + MFC VS2015

CodePudding user response:

Should someone oh,

CodePudding user response:

reference 1st floor ah_2056 response:

should someone oh,

The building Lord, the following code for reference ~ ~ ~ ~

 
Char * _stdcall stringCombo (char * str1, char * str2) 
{
Char * str3="upstring="; 
Char * str4="& amp; UpFullFileName="; 

Int nLen=strlen (str3); 
NLen +=strlen (str4); 

If (str1) 
NLen +=strlen (str1); 

If (str2) 
NLen +=strlen (str2); 

Char * combo=new char [nLen + 1]; 
If (combo) 
{
Memset (combo, 0, nLen + 1); 
Sprintf_s (combo, nLen + 1, "% s % s % s % s", str3, str1, str4, str2); 
}

Return combo. 
}


Int main () 
{
Char * pRetChar=stringCombo (" hello ", "the word"); 
If (pRetChar) 
{
Printf_s (pRetChar); 
The delete [] pRetChar; 
}
return 0; 
}

CodePudding user response:

Use snprintf,

Since using the MFC project, why not use cstrings or string, they are overloaded +, string handling very convenient

CodePudding user response:

MFC using cstrings inside dealing with string link is very convenient, nearly overloaded methods are good, you just need to call

CodePudding user response:

refer to the second floor SGHCPT response:

Quote: refer to 1st floor ah_2056 response:

Should someone oh,

The building Lord, the following code for reference ~ ~ ~ ~

 
Char * _stdcall stringCombo (char * str1, char * str2) 
{
Char * str3="upstring="; 
Char * str4="& amp; UpFullFileName="; 

Int nLen=strlen (str3); 
NLen +=strlen (str4); 

If (str1) 
NLen +=strlen (str1); 

If (str2) 
NLen +=strlen (str2); 

Char * combo=new char [nLen + 1]; 
If (combo) 
{
Memset (combo, 0, nLen + 1); 
Sprintf_s (combo, nLen + 1, "% s % s % s % s", str3, str1, str4, str2); 
}

Return combo. 
}


Int main () 
{
Char * pRetChar=stringCombo (" hello ", "the word"); 
If (pRetChar) 
{
Printf_s (pRetChar); 
The delete [] pRetChar; 
}
return 0; 
}

666 brothers

CodePudding user response:

Introducing more convenient cstrings
Cstrings stringCombo (const & amp; Cstrings str1, const & amp; Cstrings str2)
{
Cstrings str3="upstring=";
Cstrings str4="& amp; UpFullFileName=";

Return str3 + str1 + str4 + str2;
}

Int main ()
{
Cstrings pRetChar=stringCombo (" hello ", "the word");
TRACE (pRetChar);
return 0;
}

CodePudding user response:

Positive solution to the second floor, new char [] this kind of thing, you will crash program, if you do not specific requirement char * format, using cstrings more convenient, can be directly

CodePudding user response:

MFC is using cstrings class.

 cstrings _stdcall stringCombo (cstrings * str1, cstrings * str2) 
{
Cstrings str3="upstring="; 

Cstrings str4="& amp; UpFullFileName="; 

Cstrings combo=str3 + str1 + str4 + str2; 


Return combo. 
}

CodePudding user response:

Cstrings class directly +=more simple and quick operation can

Cstrings Str, Str1, Str2 Str3, Str4;

Str +=(Str1 + Str2 + + Str4 Str3);

CodePudding user response:

 char * _stdcall stringCombo (char * str1, char * str2) 
{
Char * str3="upstring="; 
Char * str4="& amp; UpFullFileName="; 
Int L=0; 
Char combo=new char [1024];//use a larger buffer, to ensure that adequate 
Char * p=combo; 

L=strlen (str3); 
Memcpy (px, str3, L); 
Px +=L; 

L=strlen (str1); 
Memcpy (px, str1, L); 
Px [L]="; ";//to separate the 
Px++; 

L=strlen (str4); 
Memcpy (px, str4, L); 
Px +=L; 

L=strlen (str2); 
Memcpy (px, str2, L); 
Px [L]=0; 

Return combo 
}

CodePudding user response:

Char combo=new char [ size ]//the size must specify the size

CodePudding user response:

Char combo=new char [size];//the size must be specified size
And it should be

Char * combo=new char [size];