How to make WinForms so that one form is positioned inside another form and when the size of the main form changes, the size of the other form (child) changes?

  • Podsokratil question, removed too much - Kromster
  • Set the StartPosition property to Manual and position as you like. To resize a child form, track the Resize event of the main form. - qzavyer

1 answer 1

If it were not for the strange limitations of the framework, you could just write childForm.Parent = parentForm , but for some reason this is prohibited. But there is no reception against the scrap, just use the SetParent function. Well and further it is banal: we create the child form, we process the SizeChanged event:

 partial class Form1 : Form { Form _child; public Form1 () { InitializeComponent(); _child = new Form { StartPosition = FormStartPosition.Manual, Left = 20, Top = 20, Width = ClientSize.Width - 40, Height = ClientSize.Height - 40, }; _child.Show(this); SetParent(_child.Handle, Handle); } protected override void OnSizeChanged (EventArgs e) { base.OnSizeChanged(e); _child.Width = ClientSize.Width - 40; _child.Height = ClientSize.Height - 40; } [DllImport ("user32.dll", SetLastError = true)] static extern IntPtr SetParent (IntPtr hWndChild, IntPtr hWndNewParent); }
  • What is the use of user32.dll in your solution? - Vladimir
  • @Vladimir To call SetParent . - Athari