Question

When I write the following:

private: System::Void queue_FormClosing(
    System::Object^ sender, 
    System::Windows::Forms::FormClosingEventArgs^ e) {
    if(e->CloseReason!=CloseReason::FormOwnerClosing) e->Cancel=true;
}

I get this error:

###\queue.h(153) : error C2039: ‘FormOwnerClosing’ : is not a member of ‘System::Windows::Forms::Form::CloseReason’
1>###\queue.h(24) : see declaration of ‘System::Windows::Forms::Form::CloseReason’
1>###\queue.h(153) : error C2065: ‘FormOwnerClosing’ : undeclared identifier

I don’t understand why this is. Can anybody help?

Answer 1

For some reason you need to fully qualify the enum as System::Windows::Forms::CloseReason::FormOwnerClosing.

Doesn’t compile:

private: System::Void Form1_FormClosing(System::Object^  sender,
                 System::Windows::Forms::FormClosingEventArgs^  e) {
  if (e->CloseReason == CloseReason::FormOwnerClosing) {
    e->Cancel = true;
  }
}

Does compile:

private: System::Void Form1_FormClosing(System::Object^  sender,
                 System::Windows::Forms::FormClosingEventArgs^  e) {
  if (e->CloseReason == System::Windows::Forms::CloseReason::FormOwnerClosing) {
    e->Cancel = true;
  }
}

No idea why you need to fully qualify it, but it allows it to compile.