c# - 按钮控件对其他类不可见

Question

我有这段代码从 SQL 查询中获取值并将值放在文本框中。我想把它放到另一个类，并从主类访问它。但我的问题是，该课程无法识别按钮（txtbox_ticketnum），因为它来自主课程。帮助！

 using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString))
        {

            using (SqlCommand com_retrieve = new SqlCommand("usp_SelectTop1Ticket", con))
            {
                com_retrieve.CommandType = CommandType.StoredProcedure;
                con.Open();
                try
                {
                    txtbox_ticketnum.Text = com_retrieve.ExecuteScalar().ToString();
                    MessageBox.Show("Ticket Has been saved. Your Ticket Number: " + com_retrieve.ExecuteScalar().ToString(), "Ticket Filed");
                }
                catch (SqlException)
                {
                    MessageBox.Show("The database has encountered an error");
                }
                catch (Exception)
                {
                    MessageBox.Show("The server has encountered an error");
                }
            }
        }

Answer 1

您的按钮 (txtbox_ticketnum) 似乎是私有的- 这是默认的 Visual Studio 行为。您可以更改它（将 txtbox_ticketnum 的“Modifiers”属性设置为“public”），或者添加您自己的属性（更好的解决方案）

public partial class MyForm {
  ...
  public String TicketNumText {
    get {
      return txtbox_ticketnum.Text; 
    }
    set {
      txtbox_ticketnum.Text = value; 
    }
  }

  ...

  MyForm form = new MyForm();

  ...

  con.Open();

  try
    {
      form.TicketNumText = com_retrieve.ExecuteScalar().ToString();
       ...