Why doesnt this work?

foreach (DataRow dataRow in dt.Rows)
{
if (dataRow["Column1"].ToString().Contains(["ExampleString"])
{
listBox1.Items.Add(dataRow["Column1"] + " " + dataRow["Column2"] + " " + dataRow["Column3"] + " " + dataRow["Column4"]);
}
}
//the above code works perfectly and returns only the rows containing the "ExampleString"
// if i try to use a SelectedText value from a combobox as a string to replace the "ExampleString", (as shown below),the listbox populates with ALL of the rows, not just the ones with the "ExampleString".
string strFromCombobox = comboBox1.SelectedText;
foreach (DataRow dataRow in dt.Rows)
{
if (dataRow["Column1"].ToString().Contains(strFromCombobox)
{
listBox1.Items.Add(dataRow["Column1"] + " " + dataRow["Column2"] + " " + dataRow["Column3"] + " " + dataRow["Column4"]);
}
}

Hi..

Are you using DataTextField and DataValueField ??

Or try string strFromCombobox = comboBox1.SelectedText.ToString().Trim();

If possible, please send the code, we can debug and figure it out ..

I had already debugged and there was nothing wrong with the result being returned at that stage of the method.

It turns out the problem was, I copied a list of names from the web, and pasted them into the comboBox. Evidently it didnt put them in as separate strings even though it showed each one on a new line. When I went back and entered the names manually it worked perfectly.

trimming the string also worked

Thanks to everyone for your assistance

what is the value of strFromCombobox ?

Exemple:

using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;
namespace ComboBoxSample2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
InitializeComboBox();
}
private void InitializeComboBox()
{
// siapkan koneksi database
SqlConnection cn = new SqlConnection(ComboBoxSample2.Properties.Settings.Default.LocalDatabase);
// siapkan data adapter untuk data retrieval
SqlDataAdapter da = new SqlDataAdapter("select account_id, description from acc_accounts", cn);
// siapkan datatable untuk menampung data dari database
DataTable dt = new DataTable();
// enclose in try-catch block
// untuk menghindari crash jika terjadi kesalahan database
try
{
// ambil data dari database
da.Fill(dt);
// bind data ke combobox
ComboBox1.DataSource = dt;
ComboBox1.ValueMember = "account_id";
ComboBox1.DisplayMember = "description";
// DONE!!!
}
catch (Exception ex)
{
// tampilkan pesan error
MessageBox.Show(ex.Message);
}
}
}
}

see your database connection

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Riddhi Valecha10y ago
Accepted answer
Hi..

Are you using DataTextField and DataValueField ??

Or try string strFromCombobox = comboBox1.SelectedText.ToString().Trim();

If possible, please send the code, we can debug and figure it out ..
David10y ago
I had already debugged and there was nothing wrong with the result being returned at that stage of the method.
It turns out the problem was, I copied a list of names from the web, and pasted them into the comboBox. Evidently it didnt put them in as separate strings even though it showed each one on a new line. When I went back and entered the names manually it worked perfectly.

trimming the string also worked
Thanks to everyone for your assistance
ali tuncer10y ago
what is the value of strFromCombobox ?
Purba Anggara10y ago
Exemple:
using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;

namespace ComboBoxSample2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            InitializeComboBox();
        }

        private void InitializeComboBox()
        {
            // siapkan koneksi database
            SqlConnection cn = new SqlConnection(ComboBoxSample2.Properties.Settings.Default.LocalDatabase);
            // siapkan data adapter untuk data retrieval
            SqlDataAdapter da = new SqlDataAdapter("select account_id, description from acc_accounts", cn);
            // siapkan datatable untuk menampung data dari database
            DataTable dt = new DataTable();
            // enclose in try-catch block
            // untuk menghindari crash jika terjadi kesalahan database
            try
            {
                // ambil data dari database
                da.Fill(dt);
                // bind data ke combobox
                ComboBox1.DataSource = dt;
                ComboBox1.ValueMember = "account_id";
                ComboBox1.DisplayMember = "description";
                // DONE!!!
            }
            catch (Exception ex)
            {
                // tampilkan pesan error
                MessageBox.Show(ex.Message);
            }
        }
    }
}
Purba Anggara10y ago
see your database connection