how to Access buttons from another form in c#

Question

I have two forms. I have a button in mainForm. When i clicked button1 the main form will show and the button1 will be Enabled false. Now i want to Enable it to True when my ChildForm gets Close. PLease help me . My code For Enable= False is

        CstmersFrm cstFm = new CstmersFrm();
        cstFm.MdiParent = this;
        cstFm.Show();
        cstFm.BringToFront();
        btnCstmr.Enabled = false;

Iam trying to Enable= True is In cstmersFrm _Closed Event

        mFrm = (mainForm)this.MdiParent;
        mFrm.btnCstmr.Enabled = true;

Answer 1

You need to register to the child form Closed event on the main form:

        Form child = new Form();
        child.MdiParent=this;
        child.Show();
        child.FormClosed+=child_FormClosed;

and then set the button to Enabled:

void child_FormClosed(object sender, FormClosedEventArgs e)
{
     btnCstmr.Enabled = true;
}