C ++ builder VCL library function introduction (1) Select blog from extcsdn

Introduction to C ++ builder VCL library functions (1)Select blog from extcsdn Keywords Introduction to C ++ builder VCL library functions (1) Source

1. Borland C ++ builder VCL memory management functions 1. allocmem Allocate memory blocks of specified bytes in the queue and initialize each allocated byte to 0. The function prototype is as follows: Void * _ fastcall allocmem (Cardinal size ); 2. sysfreemem Release the specified memory block. The function prototype is as follows: Int _ fastcall sysfreemem (void * P ); 3. sysreallocmem The memory specified by the reallocation parameter size is required. The function prototype is as follows: Void * _ fastcall sysreallocmem (void * P, int size ); Ii. Borland C ++ builder VCL file operation functions 1. fileopen Open the specified file. If a positive number is returned, the operation is successful. If the returned value is-1, the operation fails. The function prototype is as follows: Int _ fastcall fileopen (const system: ansistring filename, int mode ); 2. filecreate Create a new file with the specified file name. If a positive number is returned, the operation is successful, and the returned value is the file handle. If the returned value is-1, the operation fails. The function prototype is as follows: Int _ fastcall filecreate (const system: ansistring filename ); 3. fileread The function returns the actual number of bytes read from the file to the buffer. The function prototype is as follows; Int _ fastcall fileread (INT handle, void * buffer, int count ); 4. filewrite Write the data in the buffer to the current location of the specified file. If the operation succeeds, the function returns the number of bytes actually written. If the returned value is-1, the operation produces an error, the function prototype is as follows: Int _ fastcall filewrite (INT handle, const void * buffer, int count ); 5. FileSeek Adjust the file pointer to the new location. If the operation succeeds, the new file location is returned. If the operation fails, the function returns-1. The function prototype is as follows: Int _ fastcall FileSeek (INT handle, int offset, int origin ); 6. fileclose Close the specified file. The function prototype is as follows: Void _ fastcall fileclose (INT handle ); 7. fileage Returns the time tag of the specified file. If the operation fails,-1 is returned. The function prototype is as follows: Int _ fastcall fileage (const system: ansistring filename ); 8. fileexists Used to test whether the specified file exists. If the returned result is true or false, the function prototype is as follows: Bool _ fastcall fileexists (const system: ansistring filename ); 9. filegetdate Returns the DOS time tag of the specified file. If the operation fails, it is near-1. The function prototype is as follows: Int _ fastcall filegetdate (INT handle ); 10. filesetdate Change the DOS time tag of the specified file. If the operation succeeds, 0 is returned; otherwise, an error is returned.CodeThe function prototype is as follows: Int _ fastcall filesetdate (INT handle, int age ); 11. filegetattr Returns the properties of the specified file. If the operation fails, the function returns-1. The function prototype is as follows; Int _ fastcall filegetattr (const system: ansistring filename ); 12. filesetattr Change the attribute parameters of the specified file. If the operation is successful, 0 is returned. The function prototype is as follows; Int _ fastcall filesetattr (const system: ansistring filename, int ATTR ); 13. findfirst Search for files that meet the specified attribute parameters in the specified file directory. If the files that meet the condition are found successfully, The function returns 0. Otherwise, the function returns an error code. The function prototype is as follows: Int _ fastcall findfirst (const system: ansistring path, int ATTR, tsearchrec &; f ); 14. findnext Continue to search for the file with the attribute parameters specified by findfirst. If the file is found successfully, the function returns 0; otherwise, the function returns an error code. The function prototype is as follows: Int _ fastcall findnext (tsearchrec &; f ); 15. findclose Release the memory resources applied for by the findfirst operation. The function prototype is as follows: Void _ fastcall findclose (tsearchrec &; f ); 16. deletefile Delete the specified file from the computer disk. If the operation succeeds, the function returns true. The function prototype is as follows: Bool _ fastcall deletefile (const ansistring filename ); 17. renamefile Change the name of the specified file. If the operation succeeds, the function returns true. The function prototype is as follows: Bool _ fastcall renamefile (const ansistring oldname, const ansistring newname ); 18. changefileext Modify the extension of the specified file. The function prototype is as follows: Ansistring _ fastcall changefileext (const ansistring filename, const ansistring extension ); 19. extractfilepath Returns the working path of the specified file. The function prototype is as follows: Ansistring _ fastcall extractfilepath (const ansistring filename ); 20. extractfiledir Returns the working directory of the specified file. The function prototype is as follows: Ansistring _ fastcall extractfiledir (const ansistring filename ); 21. extractfiledrive Returns the drive of the specified file. The function prototype is as follows: Ansistring _ fastcall extractfiledrive (const ansistring filename ); 22. extractfilename Returns the name and extension of the specified file. The function prototype is as follows: Ansistring _ fastcall extractfilename (const ansistring filename ); 23. extractfileext Returns the extension of the specified file. The function prototype is as follows: Ansistring _ fastcall extractfileext (const ansistring filename );