There is no event handler to establish when a form's minimise request has been fired. So to 'get in' before the form has been minimised you'll have to hook into the WndProc procedure
private const int WM_SYSCOMMAND = 0x0112;
private const int SC_MINIMIZE = 0xF020;
[SecurityPermission(SecurityAction.LinkDemand,
Flags = SecurityPermissionFlag.UnmanagedCode)]
protected override void WndProc(ref Message m)
{
switch(m.Msg)
{
case WM_SYSCOMMAND:
int command = m.WParam.ToInt32() & 0xfff0;
if (command == SC_MINIMIZE && this.minimizeToTray)
{
PerformYourOwnOperation(); // For example
}
break;
}
base.WndProc(ref m);
}
and then you can merely hide the form in the PerformYourOwnOperation();
method
public void PerformYourOwnOperation()
{
Form form = GetActiveForm();
form.Hide();
}
You will then need some mechanism to Show()
the hidden form otherwise it will be lost.
Another way is using the the form's resize event. However, this fires after the form is minimised. To do this you can do something like
private void Form_Resize(object sender, EventArgs e)
{
if (WindowState == FormWindowState.Minimized)
{
// Do some stuff.
}
}
I hope this helps.