close and reopen child forms

faladrim

hi, if i press a button in a menu in a parent form i open a child form called form2, if i choose form3 in the menu i want to close form2 and show form3, and visa versa, but i cant do this. i get an error because the form2 is closed and i cant reopen it. it has someting to doe with the signle instance... i dont understand it :( this i what i have of code, very simple it just opens empty forms: namespace swapform { public partial class Form1 : Form { Form2 objchild1 = new Form2(); Form3 objchild = new Form3(); public Form1() { InitializeComponent(); objchild1.MdiParent = this; objchild.MdiParent = this; } private void form3ToolStripMenuItem_Click(object sender, EventArgs e) { objchild.Show(); //show form3 objchild1.Close(); // close form 2 } private void form2ToolStripMenuItem_Click(object sender, EventArgs e) { objchild1.Show(); //show form 2 objchild.Close();//close form 3 } } }

Guffa

Use the Hide method to hide the window. Once you close it you can't show it any more.

--- b { font-weight: normal; }

faladrim

i found a way, cause when i just hide the form is still open and i dont want that. here is the solution to be able to close a child form when opening another. namespace swapform { public partial class Form1 : Form { Form3 objchild = new Form3(); Form2 objchild1 = new Form2(); public Form1() { InitializeComponent(); objchild.MdiParent = this; objchild1.MdiParent = this; } private void form2ToolStripMenuItem_Click(object sender, EventArgs e) { objchild1.Close(); if ((objchild == null) | (objchild.IsDisposed)) { objchild = new Form3(); objchild.MdiParent = this; } objchild.Show(); // show form3 objchild.Top = 10;//specify the location objchild.Left = 10; objchild.Height = 550; objchild.Width =560; } private void form1ToolStripMenuItem_Click(object sender, EventArgs e) { objchild.Close(); if ((objchild1 == null) | (objchild1.IsDisposed)) { objchild1 = new Form2(); objchild1.MdiParent = this; } objchild1.Show(); // show form 2 objchild1.Top = 10;//specify the location objchild1.Left = 10; objchild1.Height = 550; objchild1.Width = 560; } } grz

Guffa

Why do you create the child forms in the constructor at all? Why don't just create them when you need them? Then you don't need the extra code to handle the case when they exist already.

--- b { font-weight: normal; }