How enable dragging a file on the *.exe and get it as parameter?

Question

What do I have to do to make my program use a file that has been dragged and dropped onto its icon as a parameter?

My current main method looks like this:

int main(int argc, char* argv[])
{
    if (argc != 2) {
        cout << "ERROR: Wrong amount of arguments!" << endl;
        cout << "\n" << "Programm closed...\n\n" << endl;
        exit(1);
        return 0;
    }

    Converter a(argv[1]);
    // ...

    cout << "\n" << "Programm finished...\n\n" << endl;

    // cin.ignore();
    return 0;
}

What I'd really like to be able to do is select 10 (or so) files, drop them onto the EXE, and process them from within my application.

---

EDIT:

The incomming parameter is used as filename, constructed in the cunstructor.

Converter::Converter(char* file) {
       // string filename is a global variable
   filename = file;
   myfile.open(filename.c_str(), ios_base::in);
}

The method where the textfile gets read:

string Converter::readTextFile() {
char c;
string txt = "";

if (myfile.is_open()) {

    while (!myfile.eof()) {
        myfile.get(c);
        txt += c;
    }

} else {
    error("ERROR: can't open file:", filename.c_str());
}
return txt;
}

---

EDIT2: deleted

Update:
I got again to this point.

Actual Main method:

// File path as argument

int main(int argc, char* argv[]) { if (argc < 2) { cout << "ERROR: Wrong amount of arguments! Give at least one argument ...\n" << endl; cout << "\n" << "Programm closed...\n\n" << endl; cin.ignore(); exit(1); return 0; }

vector<string> files;

for (int g = 1; g < argc; g++) {
    string s = argv[g];
    string filename = "";
    int pos = s.find_last_of("\\", s.size());

    if (pos != -1) {
        filename = s.substr(pos + 1);

        cout << "argv[1] " << argv[1] << endl;
        cout << "\n filename: " << filename << "\n pos: " << pos << endl;
        files.push_back(filename);

        }
    files.push_back(s);
    }

for (unsigned int k = 0; k < files.size(); k++)
    {
    cout << "files.at( " << k << " ): " << files.at(k).c_str() << endl;
    Converter a(files.at(k).c_str());
    a.getATCommandsFromCSV();
    }


cout << "\n" << "Programm finished...\n\n" << endl;

cin.ignore();

return 0;
}

Actually the console window apears for maybe 0.5 sec and closes again.
It doen't stop on any of my cin.ignore(); Maybe it doesn't get there?

Can anyone help?

Answer 1

Your program does not need to do anything special apart from handling command-line arguments. When you drag-drop a file onto an application in Explorer it does nothing more than to pass the file name as argument to the program. Likewise for multiple files.

If all you expect is a list of file names, then just iterate over all arguments, do whatever you want with them and be done. This will work for zero to almost arbitrarily many arguments.

Answer 2

Maybe you could write a test program like this:

int main(int argc, char* argv[])
{
    // argv[0] is not interesting, since it's just your program's path.
    for (int i = 1; i < argc, ++i)
        cout << "argv[" << i << "] is " << argv[i] << endl;

    return 0;
}

And see what happens after you throw different files at it.

---

EDIT: Just look at Joey's answer.

Answer 3

Answer to the main question

TO SEE THE ANSWER TO YOUR LAST PROBLEM SEE BOTTOM OF THIS ANSWER

All drag&dropped files are get-able as argv[orderOfTheFile] (orderOfTheFile is from 1-n),
however how does windows create that order, now that is a real mystery...

Anyway let's say I would create 26 plain text files ( *.txt ), from a.txt to z.txt on my Desktop,
now if I would drag&dropped them on my ArgsPrinter_c++.exe located directly on C:\ drive,
an output would be similar to this:

argc = 27
argv[0] = C:\ArgsPrinter_c++.exe
argv[1] = C:\Users\MyUserName\Desktop\c.txt
argv[2] = C:\Users\MyUserName\Desktop\d.txt
argv[3] = C:\Users\MyUserName\Desktop\e.txt
argv[4] = C:\Users\MyUserName\Desktop\f.txt
argv[5] = C:\Users\MyUserName\Desktop\g.txt
argv[6] = C:\Users\MyUserName\Desktop\h.txt
argv[7] = C:\Users\MyUserName\Desktop\i.txt
argv[8] = C:\Users\MyUserName\Desktop\j.txt
argv[9] = C:\Users\MyUserName\Desktop\k.txt
argv[10] = C:\Users\MyUserName\Desktop\l.txt
argv[11] = C:\Users\MyUserName\Desktop\m.txt
argv[12] = C:\Users\MyUserName\Desktop\n.txt
argv[13] = C:\Users\MyUserName\Desktop\o.txt
argv[14] = C:\Users\MyUserName\Desktop\p.txt
argv[15] = C:\Users\MyUserName\Desktop\q.txt
argv[16] = C:\Users\MyUserName\Desktop\r.txt
argv[17] = C:\Users\MyUserName\Desktop\s.txt
argv[18] = C:\Users\MyUserName\Desktop\t.txt
argv[19] = C:\Users\MyUserName\Desktop\u.txt
argv[20] = C:\Users\MyUserName\Desktop\v.txt
argv[21] = C:\Users\MyUserName\Desktop\w.txt
argv[22] = C:\Users\MyUserName\Desktop\x.txt
argv[23] = C:\Users\MyUserName\Desktop\y.txt
argv[24] = C:\Users\MyUserName\Desktop\z.txt
argv[25] = C:\Users\MyUserName\Desktop\a.txt
argv[26] = C:\Users\MyUserName\Desktop\b.txt

My ArgsPrinter_c++.exe source code:

#include <iostream> 
using namespace std;

int main(int argc, char* argv[]) { 
   cout << "argc = " << argc << endl; 
   for(int i = 0; i < argc; i++) 
      cout << "argv[" << i << "] = " << argv[i] << endl; 

   std::cin.ignore();
   return 0; 
}

Your last problem

I have created a simple program that creates only a sceleton of your class so it can be used, and the program's main itself ran JUST FINE => if your program exits too soon, the problem will be in your class...

Tested source code:

#include <iostream> 
#include <vector>
using namespace std;

class Converter{
    public: 
    Converter(const char* f){ cout << f << endl; }
    void getATCommandsFromCSV(){ cout << "called getATCommandsFromCSV" << endl; }
};

int main(int argc, char* argv[]) { 
  vector<string> files;

  for (int g = 1; g < argc; g++) {
      string s = argv[g];
      string filename = "";
      int pos = s.find_last_of("\\", s.size());

      if (pos != -1) {
          filename = s.substr(pos + 1);

          cout << "argv[1] " << argv[1] << endl;
          cout << "\n filename: " << filename << "\n pos: " << pos << endl;
          files.push_back(filename);

          }
      files.push_back(s);
      }

  for (unsigned int k = 0; k < files.size(); k++)
      {
      cout << "files.at( " << k << " ): " << files.at(k).c_str() << endl;
      Converter a(files.at(k).c_str());
      a.getATCommandsFromCSV();
      }

  cout << "\n" << "Programm finished...\n\n" << endl;

  cin.ignore();

  return 0;
}