Cancel A WinForm Minimize?

Question

I have a winform with the minimizeMaximizeClose buttons disabled, but still if someone presses it in the task bar, it will minimize. I want to prevent this from happening.

How can I accomplish this?

Answer 1

Override WndProc on your form, listen for minimize messages and cancel.

Add this code to your form:

private const int WM_SYSCOMMAND = 0x0112; 
private const int SC_MINIMIZE = 0xf020; 

 protected override void WndProc(ref Message m) 
{ 
    if (m.Msg == WM_SYSCOMMAND) 
    { 
        if (m.WParam.ToInt32() == SC_MINIMIZE) 
        { 
            m.Result = IntPtr.Zero; 
            return; 
        } 
    } 
    base.WndProc(ref m); 
} 

I modified Rob's code found in this SO thread:
How to disable the minimize button in C#?

Works great: no flickering, no nothing when the user attempts to minimize.

Answer 2

You could probably catch them changing it in the SizeChanged event and check the WindowState, if its been set to Minimized then set it back Normal. Not the most elegant solution but should work.

eg.

private void myForm_SizeChanged(object sender, System.EventArgs e)
{
   if (myForm.WindowState == FormWindowState.Minimized)
   {
       myForm.WindowState = FormWindowState.Normal;
   }
}

Answer 3

If it's suitable for you, just hide it from the taskbar: ShowInTaskbar=false