c＃show textbox取决于sql值

Question

我有一个winform应用程序，包含2个表单和一个数据库，form 1用户在选择pictureboxes之后从多个form2中选择textboxes并且labels和form1将根据form1中的选择显示。 问题是，应用程序无法知道在 cc(); con.Open(); SqlCommand cmd = con.CreateCommand(); cmd.CommandType = CommandType.Text; cmd.CommandText = "select prumos from dbo.modelos"; SqlDataReader dr = cmd.ExecuteReader(); if (dr.Read()) { object value; try { value = dr["prumos"]; } catch (IndexOutOfRangeException) { value = null; } string check = value != null ? value.ToString() : null; textBox13.Visible = (check == "2" || check == "3"); textBox18.Visible = (check == "2" || check == "3"); textBox17.Visible = (check == "2" || check == "3"); textBox14.Visible = check == "3"; textBox16.Visible = check == "3"; textBox15.Visible = check == "3"; label16.Visible = (check == "2" || check == "3"); label20.Visible = check == "3"; } else { } dr.Close(); con.Close(); } 中选择了哪个项目来处理来自sql的信息。 在表中有3列id，description和prumos。 如何让应用程序识别出我选择了带有id x的图片框，这对应于＆＃34; prumos＆＃34;这样应用程序可以显示正确的文本框吗？

我感谢您的帮助的代码是：

Array (
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => 5
)

非常感谢你的帮助和时间

Answer 1

更改

var check = dr["prumos"].ToString();

与

var check = dr[0].ToString();

我认为在您的DataReader中不存在＆＃39; prumos＆＃39;列，但是一个简单的文字＆＃39;结果未找到＆＃39;

试试吧

Answer 2

我只是在猜测，因为问题中没有太多信息。 所以你真正想要实现的是： 仅获取某个查询的第一行并更改某些控件“的可见性，具体取决于列的值？

如果情况确实如此，那很简单：

con.Open();

SqlCommand cmd = con.CreateCommand();
cmd.CommandType = CommandType.Text;
cmd.CommandText = "select prumos from dbo.modelos";
SqlDataReader dr = cmd.ExecuteReader();

if(dr.Read())
{ 
    // if dr.Read() returns true we already know that dr.HasRows was also true
    object value = null;
    try
    {
        value = dr["prumos"];
    }
    catch(IndexOutOfRangeException) // thrown if there is no such column
    {
    }
    string check = value != null ? value.ToString() : null;
    textBox13.Visible = (check == "2" || check == "3");
    textBox18.Visible = (check == "2" || check == "3");
    textBox17.Visible = (check == "2" || check == "3");
    textBox14.Visible = check == "3";
    textBox16.Visible = check == "3";
    textBox15.Visible = check == "3";
    label16.Visible = (check == "2" || check == "3");
    label20.Visible = check == "3";
}
else 
{
   // what to do if there is no row?
}
dr.Close();
con.Close();