C#.net中如何在TextBox中显示数据库查询结果？

我在设计中设置了四个ListBox，分别表示年月，也就是从x年x月到x年x月的一个工具出入库数量的查询。
下面是我的代码：
string toolName;
string year1,month1,year2,month2,status;

year1 = lstYear1.SelectedItem.Text;
month1 = lstMonth1.SelectedItem.Text;
year2 = lstYear2.SelectedItem.Text;
month2 = lstMonth2.SelectedItem.Text;
status = lstStatus.SelectedItem.Text;
toolName = txtToolName.Text.Trim();
SqlConnection con = new SqlConnection("server=.;database=mtc;Integrated Security=True ");
con.Open();
string tools = "select * from mtctoolstable where toolName='"+toolName+"'";
SqlCommand cmd = new SqlCommand(tools, con);
SqlDataReader dr = cmd.ExecuteReader();
if (dr.Read())
{
txtToolName.Text = dr.GetString(dr.GetOrdinal("toolName"));
}