Add a combobox in to listview control in c++ builder - c++builder

Question

I want to create a listview with 2 columns. in the first column it must be the row number and in the second number it should contains a combobox. I write the following code, but second column just show "combo" string. it does not show any combo box. what is the wrong?
for (int i = 0; i < 10; i++) {
TListItem *items;
items= this->ListView1->Items->Add();
items->Caption=IntToStr(i);
items->SubItems->AddObject("combo"+IntToStr(i),(TObject *)this->ComboBox1);
}

Answer 1

It does not show a TComboBox because you have not actually set the TComboBox to be a child control of the TListView. All you have done is store the TComboBox pointer as a user-defined value associated with the TListItem. That has no effect on the UI, so get rid of it:
for (int i = 0; i < 10; i++)
{
TListItem *items = ListView1->Items->Add();
items->Caption = IntToStr(i);
items->SubItems->Add("combo"+IntToStr(i));
}
To actually show a TComboBox inside of the TListView, you have to assign the TListView as the Parent of the TComboBox, and then use the SetBounds() method to position and size the TComboBox whenever you need to show it:
ComboBox1->Parent = ListView1;
...
RECT rect = {0};
ListView_GetSubItemRect(ListView1->Handle, SomeListItem->Index, 1, LVIR_BOUNDS, &rect);
ComboBox1->SetBounds(rect.left, rect.top, rect.right-rect.left, rect.bottom-rect.top);
// update ComboBox1->Items as needed...
ComboBox1->Visible = true;
...
ComboBox1->Visible = false;
With that said, what you are attempting to do is better handled using the TValueListEditor component instead. Add items to it as needed, then use its ItemProps property to set each item's TItemProp.EditStyle property to esPickList, and then use the TValueListEditor.OnGetPickList event or the TItemProp.PickList property to manage the ComboBox strings as needed.