C++ | How to remove the DataSource from a combobox? - c++

Question

I'm writing a windows forms application in visual studio with c++ and CLR.
And now, i got the following problem:
I read in a file and save all the important informations in a vector.
With a second step, i convert all items to a CLR array and set this array as DataSource.
array<System::String^>^ PREDEFINED = gcnew array <System::String^>(OP->CIS_Values[OP->selectedCIS]->PREDEFINED_order.size());
for (int i = 0; i < OP->CIS_Values[OP->selectedCIS]->PREDEFINED_order.size(); i++) {
PREDEFINED[i] = msclr::interop::marshal_as<System::String^>(OP->CIS_Values[OP->selectedCIS]->PREDEFINED_order[i]);
}
this->comboBox_header_predefinedtypes->DataSource = PREDEFINED;
this->comboBox_header_predefinedtypes->SelectedIndex = -1;
delete PREDEFINED;
After setting the DataSource, it must be possible to remove it. In C# i can do this with
comboBox.DataSource = null;
but how does it work in C++?
I tried the following cases:
comboBox_header_predefinedtypes->DataSource = NULL;
comboBox_header_predefinedtypes->DataSource = 0;
comboBox_header_predefinedtypes->DataSource = -1;
comboBox_header_predefinedtypes->DataBindings->Clear();
comboBox_header_predefinedtypes->Items->Clear();
I tried it with DataBindings before and after DataSource, but i always get the same exception:
System.ArgumentException: "The complex DataBinding accepts as a data source either IList or IListSource"
How can i fix this issue ?
Thx for help.

Answer 1

In C++ CLR you only need to write:
comboBox_header_predefinedtypes->DataSource = nullptr;
and you don't need to write
comboBox_header_predefinedtypes->Items->Clear();
after removing the DateSource to delete the items.