How to use directory operations in C++Builder? - directory

Question

I am stuck in creating a directory with C++Builder. If you check this here and here, I find examples for my case, but when I try to use them, none of them work for me! For example, the following code for creating a directory, where the edSourcePath->Text value has been defined.
Unfortunately the documentation is not complete.
try
{
/* Create directory to specified path */
TDirectory::CreateDirectory(edSourcePath->Text);
}
catch (...)
{
/* Catch the possible exceptions */
MessageDlg("Incorrect path", mtError, TMsgDlgButtons() << mbOK, NULL);
return;
}
The error message says TDirectory is not a class or namespace.
Another question is, how can I pass the source path and directory name by CreateDirectory(edSourcePath->Text)?

Answer 1

What you are seeing is a compile-time error, not a runtime error. The compiler cannot find the definition of the TDirectory class. You need to #include the header file that TDirectory is defined in, eg:
#include <System.IOUtils.hpp> // <-- add this!
try
{
/* Create directory to specified path */
TDirectory::CreateDirectory(edSourcePath->Text);
// or, if either DELPHIHEADER_NO_IMPLICIT_NAMESPACE_USE or
// NO_USING_NAMESPACE_SYSTEM_IOUTILS is defined, you need
// to use the fully qualified name instead:
//
// System::Ioutils::TDirectory::CreateDirectory(edSourcePath->Text);
}
catch (const Exception &e)
{
/* Catch the possible exceptions */
MessageDlg("Incorrect path.\n" + e.Message, mtError, TMsgDlgButtons() << mbOK, NULL);
return;
}
Note, however, that TDirectory::CreateDirectory() throws an exception ONLY if the input String is not a valid formatted path. It DOES NOT throw an exception if the actual directory creation fails. In fact, there is no way to detect that condition with TDirectory::CreateDirectory() itself, you would have to check with TDirectory::Exists() afterwards:
#include <System.IOUtils.hpp>
try
{
/* Create directory to specified path */
String path = edSourcePath->Text;
TDirectory::CreateDirectory(path);
if (!TDirectory::Exists(path))
throw Exception("Error creating directory");
}
catch (const Exception &e)
{
/* Catch the possible exceptions */
MessageDlg(e.Message, mtError, TMsgDlgButtons() << mbOK, NULL);
return;
}
Otherwise, TDirectory::CreateDirectory() is just a validating wrapper for System::Sysutils::ForceDirectories(), which has a bool return value. So, you could just call that function directly instead:
#include <System.SysUtils.hpp>
/* Create directory to specified path */
if (!ForceDirectories(edSourcePath->Text)) // or: System::Sysutils::ForceDirectories(...), if needed
{
MessageDlg("Error creating directory", mtError, TMsgDlgButtons() << mbOK, NULL);
return;
}