The use of MFC Cstring classes

CString is located in the header file afx.h.

member functions for CStringthe CString constructor CString (); Example: CString csstr; CString (const cstring& STRINGSRC); Example: CString csstr ("abcdef Chinese 123456"); CString csStr2 (CSSTR); CString (TCHAR ch, int nrepeat = 1); Example: CString csstr (' A ', 5); Csstr= "AAAAA" CString (LPCTSTR lpch, int nlength); Example: CString csstr ("ABCdef", 3); Csstr= "ABC" CString (LPCWSTR lpsz); Example: wchar_t s[]=l "abcdef"; CString Csstr (s); Csstr=l "ABCdef" CString (const unsigned char* psz); Example: const unsigned char s[]= "abcdef"; const unsigned char* sp=s; CString Csstr (SP); Csstr= "ABCdef" CString (LPCSTR lpsz); Example: CString csstr ("abcdef"); Csstr= "ABCdef" int getlength () const; Returns the length of a string that does not contain the trailing null character. Example: csstr= "abcdef Chinese 123456"; printf ("%d", csstr.getlength ()); 16 void Makereverse (); Reverse the order of strings Example: csstr= "abcdef Chinese 123456"; Csstr.makereverse (); cout<<csstr; 654321 text in FEDCBA void Makeupper (); Convert lowercase letters to uppercase Example: csstr= "abcdef Chinese 123456"; Csstr.makeupper (); cout<<csstr; ABCdef Chinese 123456 void Makelower (); Convert uppercase letters to lowercase Example: csstr= "abcdef Chinese 123456"; Csstr.makelower (); cout<<csstr; ABCdef Chinese 123456 int Compare (LPCTSTR lpsz) const; Case sensitivity compares two strings, returns 0 when equal, returns 1 when it is less than 1 Example: csstr= "abcdef Chinese 123456"; Csstr2= "abcdef Chinese 123456"; Cout<<csstr.comparenocase (CSSTR2); 0 int comparenocase (LPCTSTR lpsz) const; Case-insensitive comparison of two strings, equal when returning 0, greater than 1, and less than return-1 Example: csstr= "abcdef Chinese 123456"; Csstr2= "abcdef Chinese 123456"; Cout<<csstr.comparenocase (CSSTR2); -1 int Delete (int nIndex, int ncount = 1) Delete characters, delete ncount characters starting from subscript nindex Example: csstr= "ABCDEF"; Csstr.delete (2,3); cout<<csstr; ABF The function has no action when the nindex is too large to exceed the memory area of the image. When nindex is negative, it is deleted from the first character. Unpredictable results occur when the ncount is too large, resulting in the deletion of characters beyond the memory area where the image is located. When ncount is negative, the function has no action. int Insert (int nIndex, TCHAR ch) int Insert (int nIndex, LPCTSTR pstr) Inserts a character or string in the position labeled Nindex. Returns the length of the inserted object Example: csstr= "abc"; Csstr.insert (2, ' X '); cout<<csstr; Abxc csstr= "ABC"; Csstr.insert (2, "XYZ"); cout<<csstr; Abxyzc When nindex is negative, insert at the beginning of the object Insert at end of object when Nindex is beyond end of object int Remove (TCHAR ch); Removes the specified character within the object. Returns the number of removal Example: csstr= "AABBAACC"; Csstr.remove (' a '); cout<<csstr; Bbcc int Replace (TCHAR chold, TCHAR chnew); int Replace (LPCTSTR lpszold, LPCTSTR lpsznew); Replace string Example: csstr= "abcdef"; Csstr.replace (' A ', ' X '); cout<<csstr; Xbcdef Csstr= "ABCdef"; Csstr.replace ("abc", "XYZ"); cout<<csstr; Xyzdef void Trimleft (); void Trimleft (TCHAR chtarget); void Trimleft (LPCTSTR lpsztargets); Delete the character from the left, the deleted character matches the Chtarget or lpsztargets, and always deletes the first mismatched character. Example: csstr= "Aaabaacdef"; Csstr.trimleft (' a '); cout<<csstr; Baacdef Csstr= "Aaabaacdef"; Csstr.trimleft ("AB"); cout<<csstr; Cdef Remove spaces when no arguments void TrimRight (); void TrimRight (TCHAR chtarget); void TrimRight (LPCTSTR lpsztargets); Delete the character from the right, and the deleted character matches the Chtarget or lpsztargets, until the first mismatched character is deleted. Example: csstr= "ABCDEAAFAAA"; Csstr.trimright (' a '); cout<<csstr; Abcdeaaf Csstr= "ABCDEAAFAAA"; Csstr.trimright ("FA"); cout<<csstr; Abcde Remove spaces when no arguments void Empty (); Empty Example: csstr= "abcdef"; Csstr.empty (); printf ("%d", csstr.getlength ()); 0 BOOL IsEmpty () const; Tests whether the object is empty, returns zero when empty, and returns nonzero when not empty Example: csstr= "abc"; Cout<<csstr.isempty (); 0; Csstr.empty (); Cout<<csstr.isempty (); 1; int Find (TCHAR ch) const; int Find (LPCTSTR lpszsub) const; int Find (TCHAR ch, int nstart) const; int Find (LPCTSTR pstr, int nstart) const; Find the string, Nstart is the location to start looking for. Returns 1 if no match is found, otherwise returns the start of the string Example: csstr= "abcdef"; Cout<<csstr.find (' B '); 1 Cout<<csstr.find ("de"); 3 Cout<<csstr.find (' B ', 3); -1 Cout<<csstr.find (' B ', 0); 1 Cout<<csstr.find ("de", 4); -1 Cout<<csstr.find ("de", 0); 3 Returns 1 when Nstart exceeds the end of the object. When Nstart is negative, returns-1. int findoneof (LPCTSTR lpszcharset) const; Finds the matching position of any character in the Lpszcharset in the CString object. Returns 1 if not found, otherwise returns the starting position of the string Example: csstr= "abcdef"; Cout<<csstr.findoneof ("Cxy"); 2 CString spanexcluding (LPCTSTR lpszcharset) const; Returns a substring before the first character in an object that matches any of the Lpszcharset Example: csstr= "abcdef"; Cout<<csstr.spanexcluding ("CF"); Ab CString spanincluding (LPCTSTR lpszcharset) const; Finds a character that does not match any character in Lpszcharse, and returns the string before the first unmatched character Example: csstr= "abcdef"; Cout<<csstr.spanincluding ("FDCBA"); Abcd int reversefind (TCHAR ch) const; Finds the first match from the back forward and returns the subscript when it is found. Returned when not found-1 Example: Csstr= "ABBA"; Cout<<csstr.reversefind (' a '); 3 void Format (LPCTSTR lpszformat, ...); void Format (UINT nformatid, ...); Formatted object, same as sprintf function usage for C language Example: Csstr.format ("%d", 13); cout<<csstr; 13 TCHAR GetAt (int nIndex) const; Returns the character labeled Nindex, same as the [] usage of the string Example: csstr= "abcdef"; Cout<<csstr.getat (2); C Unpredictable results occur when nindex is negative or exceeds the end of the object. void SetAt (int nIndex, TCHAR ch); Reassign a character that is labeled nindex Example: csstr= "abcdef"; Csstr.setat (2, ' X '); cout<<csstr; Abxdef Unpredictable results occur when nindex is negative or exceeds the end of the object. CString Left (int ncount) const; Take a string from the left Example: csstr= "abcdef"; Cout<<csstr.left (3); Abc When ncount equals 0 o'clock, returns NULL. When ncount is negative, the return is empty. When Ncount is greater than the length of the object, the return value is the same as the object. CString Right (int ncount) const; Pick a string from the right Example: csstr= "abcdef"; Cout<<csstr.right (3); Def When ncount equals 0 o'clock, returns NULL. When ncount is negative, the return is empty. When Ncount is greater than the length of the object, the return value is the same as the object. CString Mid (int nfirst) const; CString Mid (int nfirst, int ncount) const; Pick a string from the middle Example: csstr= "abcdef"; Cout<<csstr.mid (2); Cdef Csstr= "ABCdef"; Cout<<csstr.mid (2,3); Cde When Nfirst is 0 and negative, the first character starts fetching. Returns an empty string when Nfirst equals the end of the object. Unexpected results occur when the Nfirst exceeds the end of the object. Returns a string from Nfirst to the end of the object when ncount exceeds the end of the object When ncount is 0 and negative, an empty string is returned. LPTSTR GetBuffer (int nminbuflength); Request a new space and return a pointer Example: csstr= "ABCDE"; LPTSTR Pstr=csstr.getbuffer (10); strcpy (PSTR, "12345"); Csstr.releasebuffer (); Pstr=null; Cout<<csstr//12345 After you finish using GetBuffer, you must use ReleaseBuffer to update the object's internal data, otherwise unpredictable results can occur. void ReleaseBuffer (int nnewlength =-1); After you use GetBuffer, you must use ReleaseBuffer to update the object's internal data Example: csstr= "abc"; LPTSTR Pstr=csstr.getbuffer (10); strcpy (PSTR, "12345"); Cout<<csstr.getlength (); 3 (incorrect usage) Csstr.releasebuffer (); Cout<<csstr.getlength (); 5 (correct) Pstr=null; Any method of the CString object should be called after ReleaseBuffer LPTSTR getbuffersetlength (int nnewlength); Request a new space and return a pointer Example: csstr= "abc"; Csstr.getbuffersetlength (20); cout<<csstr; Abc Count<<csstr.getlength (); 20; Csstr.releasebuffer (); Count<<csstr.getlength (); 3; You do not have to use ReleaseBuffer after you use GetBufferSetLength.