我在执行下面的delete操作时出现图片上的错误,请各位指点指点.
protected void Gv_userlist_RowDeleting(object sender, GridViewDeleteEventArgs e)
{//删除
string st_sqlstr = "delete from Users where User_id=@userid";
SqlCommand st_comm = new SqlCommand(st_sqlstr, conn);
st_comm.Parameters.Add(new SqlParameter("@userid", SqlDbType.VarChar, 50));
//st_comm.Parameters["@userid"].Value = st_dtg_userinformation.DataKeys[(int)e.Item.ItemIndex];
//st_comm.Parameters["@userid"].Value = Gv_userlist.DataKeys[(int)e.RowIndex].ToString();//debug
st_comm.Parameters["@userid"].Value=Gv_userlist.DataKeys[(int)e.RowIndex].Values[0].ToString();
st_comm.Connection.Open();
try
{
st_comm.ExecuteNonQuery();
Lbl_note.Text = "删除成功";

}
catch (SqlException)
{
Lbl_note.Text = "删除失败";
Lbl_note.Style["color"] = "red";
}
st_comm.Connection.Close();
St_BindGridView();
}

SqlConnection con = DB.CreateConn();
con.Open();

string sqlstr0 = "delete from Teacher_course where Teacher_course.Teacher_id='" + Gv_teach.DataKeys[e.RowIndex].Value.ToString() + "'";
string sqlstr1 = "delete from Teacher where Teacher_id='"+Gv_teach.DataKeys[e.RowIndex].Value.ToString()+"'";
SqlCommand sqlcom0 = new SqlCommand(sqlstr0, con);
sqlcom0.ExecuteNonQuery();

SqlCommand sqlcom1 = new SqlCommand(sqlstr1, con);
sqlcom1.ExecuteNonQuery();
try
{
sqlcom1.ExecuteNonQuery();
Lbl_note.Text = "删除成功";
Lbl_note.Style["color"]="green";

}
catch (SqlException)
{
Lbl_note.Text = "删除失败";
Lbl_note.Style["color"] = "red";
}
sqlcom0.Connection.Close();
sqlcom1.Connection.Close();
St_BindGridView();
这个程序在删除时没有执行try语句,请问怎么改?

protected void Gv_teach_RowDeleting(object sender, GridViewDeleteEventArgs e)
{//删除数据
SqlConnection con = DB.CreateConn();
con.Open();
//先删除子表
string sqlstr0 = "delete from Teacher_course where Teacher_course.Teacher_id='" + Gv_teach.DataKeys[e.RowIndex].Value.ToString() + "'";
//删除主表
string sqlstr1 = "delete from Teacher where Teacher_id='" + Gv_teach.DataKeys[e.RowIndex].Value.ToString() + "'";
SqlCommand sqlcom = new SqlCommand(sqlstr0, con);
sqlcom.ExecuteNonQuery();
sqlcom = new SqlCommand(sqlstr1,con);
try
{
sqlcom.ExecuteNonQuery();
Lbl_note.Text = "删除成功";
Lbl_note.Style["color"] = "green";

}
catch (SqlException)
{
Lbl_note.Text = "删除失败";
Lbl_note.Style["color"] = "red";
}
sqlcom.Connection.Close();
St_BindGridView();
}
删除数据还是不能显示"删除成功"和删除失败",怎么做呢?帮帮忙啊!我不行了.