Why flowlayoutpanel controls count 0 C#

Question

I'm creating 3 textbox and add to the flowlayoutpanel, but flowlayoutpanel control count 0.Why does the number of checks appear to be 0, what is the reason?

  internal void Create_TextBox_Click(object sender, EventArgs e)
    {
        var Dynamic = sender as TextBox;
        Regex regex = new Regex(@"\d+");
        Match match = regex.Match(Dynamic.Name);
        if (match.Success)
        {
            if(Dynamic.Name == "txtCash"+match.Value)
            {
                TextBox DynamicDataOne = fp.Controls.Find("txt" + match.Value, true)[0] as TextBox;
                TextBox DynamicDataTwo = fp.Controls.Find("txtTwo" + match.Value, true)[0] as TextBox;
                int _One;
                int _Two;
                if (int.TryParse(DynamicDataOne.Text, out _One) && int.TryParse(DynamicDataTwo.Text, out _Two))
                    Dynamic.Text = (_One * _Two).ToString();
            }
        }
    }

Answer 1

您可以轻松地执行以下操作：

var textboxes = fp.Controls.OfType<TextBox>().Where(x=> Regex.IsMatch(x.Name, "txtCash\\d+"));

Answer 2

I solved the problem in this way;

    string GetTextBox()
    {
        TextBox txt = fp.Controls.Find("txt1", true)[0] as TextBox;
        return txt.Text;
    }

But why can't I do it in the event?