using System.Runtime.InteropServices; [DllImport("user32")]
public static extern int SetParent(int hWndChild, int hWndNewParent); Form2 f2 = new Form2();
f2.MdiParent = this;
f2.Show();
SetParent((int)f2.Handle, (int)this.Handle);
using System.Runtime.InteropServices; [DllImport("user32")]
public static extern int SetParent(int hWndChild, int hWndNewParent); Form2 f2 = new Form2();
f2.MdiParent = this;
f2.Show();
SetParent((int)f2.Handle, (int)this.Handle);