I know, that there are many questions related to this, but still I cannot find a workable solution.
Usually, it would work like this: A form creates an instance of another form in it's container like this:
Dim PolInstIn As New SubForm1
Private Sub LoadDetail()
PolInstIn.TopLevel = False
PolInstIn.Name = "Sub From"
PolInstIn.FormBorderStyle = Windows.Forms.FormBorderStyle.None
PolInstIn.Dock = DockStyle.Fill
I see this question got a lot of views, so here is an answer.
1) No visual response of child form (only results) - this could have happened if I created more then 1 instances of the form. The example is just an example, but if one use it (accidentally) this way, it may result in new definition of a child form every time (and consequent symptoms like the ones described). In practice, I split form loading from loading data into to the form (done by a public sub in that form).
2) If you want also a back reference (to i.e. parent grid form), define a Public ParentFormGrid as GridName (note ParentForm is a reserved name) and on loading a child form, set
PollInstIn.ParentFormGrid = Me
This way you can alway asccess the parent form, i.e. reload the grid when you save changes on a line edited in child form.