Sets the size of a file or alternate stream.
int SetFileSize(const QString& qsFileName, qint64 lSize, const QString& qsPassword);
This method sets the size of the file or alternate stream specified by FileName.
The value passed for FileName must be a vault-local absolute path.
The Size parameter specifies the new size of the file or alternate stream, which must be greater than or equal to 0.
Note: This method can only be called when Active is true, and cannot be called within events.
This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)