Tips related to tool 02-MFC string

This article mainly summarizes some knowledge related to MFC programming string under Windows, such as the use of CString, CStringList, etc


The best string class used in MFC should be CString. CString is a class in MFC, which contains many easy-to-use operations, such as Format, search, calculate length, etc

To use CString, you need to reference the header file in the project: #include < AFX h> , usually placed in StdAfx H in the precompiled header In addition, you need to select "use MFC in shared DLL" in the project properties

There were previous projects in VC6 0. Later, it was migrated to VS2013. At the beginning, a large number of errors were reported about CString, and it was found that it was characters from different platforms For coding problems, Download Multibyte MFC Library for Visual Studio 2013 from the Internet. After installation, select Multi byte encoding instead of Unicode, that is, there is no encoding problem, and CString can be used freely

// use_CString.c

// initialization
CString s;
CString s("hello");
CString s = "hello";

char c[] = "hello";
CString s = "";
s.Format("%s", c);

CString s = "hello";
// length
// Note: each character in English takes up one length, and each character in Chinese takes up two lengths
printf("%d", s.GetLength());    // 5

// reversal
s.MakeReverse();    // "olleh"

// Convert case
s.MakeUpper();      // "HELLO"
s.MakeLower();      // "hello"

// Insert delete
s.Insert(2, "a");   // "heallo"
s.Delete(3, 2);     // "hel"

// Replace and remove specified characters
s.Replace("ll", "yy");  // "heyyo"
s.Remove('l');          // "heo"

// Remove left and right spaces
// Generally, when reading a string from a file, the spaces at both ends will be removed first to prevent reading meaningless data
s.TrimLeft();   // The left space is removed by default
s.TrimRight("a");  // Remove any number of "a" at the right end

// Clear the string and judge whether the string is empty
// Judging whether it is empty is also commonly used to read files
s.IsEmpty();    // Returns 0 when null

// lookup
s.Find('e');    // 1
s.Find('ll');   // 2
s.Find('e', 1); // 0
s.Find('a');    // Return - 1 not found
s.ReverseFind('e'); // Reverse search, that is, reverse first and then find, 3

// format
s.Format("%d", 2);  // "2"

// Value taking and assignment
s.GetAt(2); // "l" 	 If the index is out of bounds, an exception will occur
s.SetAt(2, 'h');    // "hehlo"

s.Left(2);  // "he"
s.Right(2);  // "lo"
s.Mid(2, 2);    // "ll"
s.Mid(2);   // "llo"

CString interconverts with other types

CString is commonly used in MFC with high security but poor portability string is commonly used in STL char * is commonly used for input parameters of API

// convert_CString.c

// 1 CString and char*
CString s = "hello";
char *p = (LPSTR)(LPCTSTR)s;

char p[] = "world";
s.Format("%s", p);

// 2 CString and string
CString s;
string str = "hello";
s.Format("%s", str.c_str());

CString s = "hello";
string str(s.GetBuffer()); // string type cannot be printed with printf

// 3 char and string
char p[] = "hello";
string str(p);

const char *c = str.c_str();

// 4 CString and int
int i = atoi(s); // atof for floating point conversion
int i = _ttoi(s);

CString.Format("%d", i);

// 5 CString and char[100]
char a[100];
CString s("abc");
strncpy(a, (LPCTSTR)s, sizeof(a)); // vs2013 reports an error. Strncpy is required_ s


CStringList is a linked list defined in MFC for storing CString strings

// use_CStringList.c

// structure
CStringList str_list;

// Add or remove elements
str_list.AddHead("123");    //Add an element at the head of the list
str_list.AddTail("123");    //Add an element at the end of the list

str_list.InsertBefor(POSITION pos, "123");     // Insert new element before positioning
str_list.InsertAfter(POSITION pos, "123");     // Insert new element after positioning

str_list.RemoveHead();      // Delete the head, tail and all elements respectively

// visit
str_list.GetHead();         // Get header and tail elements

str_list.GetAt(POSITION pos);           // Gets the element at the specified location
str_list.SetAt(POSITION pos);           // Sets the element at the specified location
str_list.RemoveAt(POSITION pos);        // Deletes the element at the specified location

// Traversal used
str_list.GetHeadPosition(); // Get the position of the head and tail elements

str_list.GetNext(POSITION pos);         // Get next element
str_list.GetPrev(POSITION pos);         // Get previous element

// lookup
POSITION pos = str_list.Find("123");            // Gets the position of the element specified by the string
POSITION pos = str_list.FindIndex(int i);       // Gets the location of the element specified by the index

// state
str_list.GetCount();        // Returns the number of elements
str_list.IsEmpty();          // Is the test list empty

// ergodic
pos = str_list.GetHeadPosition();
while (pos != NULL)
    CString s = str_list.GetNext(pos);
    printf("%s", s);


1 How to solve the error MSB8031 when migrating VC6 to VS2013 2 CString class library for non MFC projects under VS2008 3 Usage of CString member function 4 CString to LPCSTR method supplement 5 CString Format function VS2013 6 CString to char *,strings 7 Detailed explanation of string function in C language 8 CSTRINGLIST usage 9 Conversion between CString,string,char * 10 MFC CString and int convert to each other

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A small problem

When writing this summary, there are ten links in the final appendix. I tested them on the local localhost. These ten links can only display six, It's the same as the last part of the page [, and it doesn't look the same as the last part of the page [) A space is added between them. Occasionally, ten links will appear normally, and then there will be no refresh. Finally, the display from deploy to github is normal The reason has not been found yet. Write down the problem first and then deal with it

Added by rea|and on Wed, 02 Mar 2022 12:18:31 +0200