WindowsForms System String

this->dataGridView1[0,i]->Value->ToString

fstream file;
//...
file << "aaa";
//...

static const string SysToStd(System::String^ SysStr)
{
    using namespace Runtime::InteropServices;
    char *v = (char*)(Marshal::StringToHGlobalAnsi(SysStr)).ToPointer();
    string result = string (v);
    Marshal::FreeHGlobal(System::IntPtr((void*)v));
    return result;
}

private: System::Void сохранитьToolStripMenuItem_Click(System::Object^  sender, System::EventArgs^  e)
         {
            unsigned short i;
            string a;
            file.open("C:\\Kurs\\Kurs.txt", ios::out, ios::trunc);
            file << this->dataGridView1->RowCount << "\n";
            for (i=0; i<this->dataGridView1->RowCount; i++)
            {
                a = SysToStd (this->dataGridView1[0,i]->Value->ToString) << "\n";
                file << a.c_str();
            }
            file.close();
         }

String^ str="";
for (int i=0; i<dataGridView1->Rows->Count; i++) {
    for (int j=0; j<dataGridView1->Rows[i]->Cells->Count; j++)
        str+=dataGridView1->Rows[i]->Cells[j]->Value+"\t";
    str+="\r\n";
}
File::WriteAllText("C:\\Kurs\\Kurs.txt", str);