I'm not sure this code will delete or not.
Try this,
string selCmdString = "SELECT *FROM Resources_Required";
SqlCommand selCommand = new SqlCommand(selCmdString, conn);
string delCmdString = "DELETE FROM Resources_Required WHERE Resources=@Res";
SqlCommand delCommand = new SqlCommand(delCmdString, conn);
SqlDataAdapter adp = new SqlDataAdapter(selCommand);
adp.DeleteCommand = delCommand;
DataRowView curRowView = (DataRowView)listBox1.SelectedItem;
String resources = curRowView["Resources"].ToString();
SqlParameter param = New SqlParameter();
param.ParameterName = "@Res";
param.Value = resources;
param.SqlDbType = SqlDbType.SmallInt;
delCommand.Parameters.Add(param);
DataSet ds = new DataSet();
adp.Fill(ds,"Resources_Required");
DataTable dt = ds.Tables["Resources_Required"];
foreach (DataRow ro in dt.Rows)
{
if (ro["Resources"].ToString() == resources)
{
ro.Delete();
break;
}
}
adp.Update(ds,"Resources_Required");
listBox1.DataSource = ds.Tables[0];
listBox1.DisplayMember = "Resources";
listBox1.ValueMember = "Resources";
cboresources.Focus();
Try now.