Question

I dispose a object in my code and I want to now create it again.

How can I do this?

Answer is :

private void showToolStripMenuItem_Click(object sender, EventArgs e)
    {
        xpPanelGroup1.CreateControl();
        xpPanelGroup1.Visible = true;
         ...


    }
    private void noShowToolStripMenuItem_Click(object sender, EventArgs e)
            {
                xpPanelGroup1.Visible = false;
                  ...
                xpPanelGroup1.Dispose();
            }

Answer 1

You need to create a new object after you have called Dispose().

But if you want to reuse the object later you should not dispose it, you may try to use Hide or .Visible = false or similar if you temporarily want to hide a control.

Edit: In your code you create a new xpPanelGroup1:

UIComponents.XPPanelGroup xpPanelGroup1 = new UIComponents.XPPanelGroup() ;

but that is only local to the showToolStripMenuItem_Click method. If you just type

xpPanelGroup1 = new UIComponents.XPPanelGroup() ;

you are using the class member, that is the same variable you dispose in the noShow method.
But I still recommend just hiding instead of disposing.