FormStartPosition.CenterParent does not work
I found setting the location manually is the only reliable option in some more complex cases when form is auto-sized and dynamically modified.
However rather than computing the coordinates manually, I'd suggest using existing method:
this.CenterToParent();
This is because you are not telling f2
who its Parent
is.
If this is an MDI application, then f2
should have its MdiParent
set to f1
.
Form f2 = new Form() { Width = 400, Height = 300 };
f2.StartPosition = FormStartPosition.CenterParent;
f2.MdiParent = f1;
f2.Show();
If this is not an MDI application, then you need to call the ShowDialog
method using f1
as the parameter.
Form f2 = new Form() { Width = 400, Height = 300 };
f2.StartPosition = FormStartPosition.CenterParent;
f2.ShowDialog(f1);
Note that CenterParent
does not work correctly with Show
since there is no way to set the Parent
, so if ShowDialog
is not appropriate, the manual approach is the only viable one.
If you set the owner of the child form like so:
Form2 f = new Form2();
f.Show(this);
You can then center it easily like this:
Form2_Load(object sender, EventArgs e)
{
if (Owner != null)
Location = new Point(Owner.Location.X + Owner.Width / 2 - Width / 2,
Owner.Location.Y + Owner.Height / 2 - Height / 2);
}
I'm using this code inside my main form, hope it helps:
var form = new MyForm();
form.Show();
if (form.StartPosition == FormStartPosition.CenterParent)
{
var x = Location.X + (Width - form.Width) / 2;
var y = Location.Y + (Height - form.Height) / 2;
form.Location = new Point(Math.Max(x, 0), Math.Max(y, 0));
}