Hello Team, Please I have this error in my C# window form application, Kindly help.
private void cmbRoom_SelectedIndexChanged(object sender, EventArgs e)
{
if (cmbRoom.SelectedIndex != -1)
{
ComboBox comboBox = (ComboBox)sender;
DataRowView selectedRow = (DataRowView)comboBox.SelectedItem;
if (selectedRow != null)
{
string selectedValue = selectedRow["roomID"].ToString();
string sqlQuery = "SELECT rRate FROM tblRoom WHERE roomID = @selectedValue";
using (SqlConnection sqlConnection = new SqlConnection(con_string))
{
sqlConnection.Open();
using (SqlCommand cmd = new SqlCommand(sqlQuery, sqlConnection))
{
cmd.Parameters.AddWithValue("@selectedValue", selectedValue);
using (SqlDataAdapter da = new SqlDataAdapter(cmd))
{
DataTable dt = new DataTable();
da.Fill(dt);
if (dt.Rows.Count > 0)
{
txtRate.Text = dt.Rows[0]["rRate"].ToString();
}
}
}
}
}
