检查c＃中flowLayoutPanel是否为空

Question

I want to make an error label come up when my flowLayoutPanel is empty, but i don't know how to check that the flowLayoutPanel is empty. This is my current code:

private void flowLayoutPanel1_ControlRemoved(object sender, ControlEventArgs e)
        {
            if (flowLayoutPanel1.Controls == null)
            {
                customtoolwarning.Visible = true;
            }
            else
            {
                customtoolwarning.Visible = false;
            }
        }

Please Help,

Thanks

Answer 1

private void flowLayoutPanel1_ControlRemoved(object sender, ControlEventArgs e)
        {
            if (flowLayoutPanel1.Controls.Count > 0)
            {
                customtoolwarning.Visible = true;
            }
            else
            {
                customtoolwarning.Visible = false;
            }
        }

Answer 2

The problem you're running into is you're checking Controls for null to determine if it's empty. The Controls property won't ever be null but instead will be non-null and have 0 length when empty. For example

if (flowLayoutPanel1.Controls.Count == 0) {
  // It's empty
}

Answer 3

lblNoContacts.Visible = (flowLayoutPanel.Controls.Count == 0) ? true : false;