C# combobox search anywhere within list, not just first letter using datatable filter

Question

0.00/5 (No votes)

See more:

i want to implement combobox (search anywhere within list, not just first letter). i saw this here but didn't help me.

i using following code

C#

private void cmbMenuName_TextChanged(object sender, EventArgs e)
    {
           DataTable dt = dtMenuOriginal;//dtMenuOriginal-Orginal data
      dt.DefaultView.RowFilter = string.Format("MenuName LIKE '%{0}%'", cmbMenuName.Text);

          cmbMenuName.DataSource = dt;
     }

this code is only working for first character Press please tell me on which event i will call or any other way to solve this

Posted 30-Nov-14 0:07am

ranjeet11

Updated 17-Oct-18 6:28am

Add a Solution

3 solutions

Solution 3

You can use Linq[^] to filter data in a datatable:

C#

string filteredColumn = "enter_proper_column_name";
string searchedText = textBox1.Text;
DataTable dt = (DataTable)comboBox1.DataSource;

//query
var qry = from DataRow dr in dt.Rows
          where dr[filteredColumn].ToString().ToLower().Contains(searchedText.ToLower())
          select dr;
dt = qry.CopyToDataTable();
this.comboBox1.DataSource = dt;

Note: above code does not contain error handler... and does not check for empty string in a textBox1. So, you have to handle it.
Do not forget to add a method/function to clear "filter" ;)

For furter information, please see: DataTableExtensions.CopyToDataTable<T> Method (IEnumerable<T>)[^]

Posted 3-Dec-14 9:07am

Maciej Los

Solution 4

This is another Good solution. You can write it for _KeyPress Event and until you press "Enter" it won't trigger...

//search function which u can re-use
private void serchOnCMB(System.Data.DataTable dt,ComboBox cmb)
{

dt.DefaultView.RowFilter = string.Format("cmb_loaded_column_Header LIKE '%{0}%'", cmb.Text);
cmb.DataSource = dt;
}

//CMB KeyPress Event
private void cmbNames_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == Convert.ToChar(Keys.Enter))
{
serchOnCMB(dtNames, cmbNames);
}
}

Posted 17-Oct-18 6:28am

hasithkuma

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

ranjeet11 · Accepted Answer · 2014-12-03T02:24:00

i solve this problem using this http://www.emoreau.com/Entries/Articles/2012/04/A-more-useful-auto-complete-Textbox-control.aspx[^].following is the solution

C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Collections;

namespace AutoCompleteDemoCS
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
            //don't forget to create/initialize our own autocomplete listbox
            this.InitializeAutoComplete();
        }
        private void InitializeAutoComplete()
        {
            this.SuspendLayout();
            //Create a new listbox that will be shown for the auto-complete
            // 
            // _listBox
            // 
            _listBox = new System.Windows.Forms.ListBox();
            _listBox.Visible = false;
            _listBox.Location = new System.Drawing.Point(0, 0);
            _listBox.Name = "_listBox";
            _listBox.Size = new System.Drawing.Size(120, 96);
            _listBox.TabIndex = 0;
            _listBox.MouseDown += new System.Windows.Forms.MouseEventHandler(this._listBox_MouseDown);
            // 
            // AutoCompleteTextBox - attach some events
            // 
            cmbMenuName.KeyDown += new System.Windows.Forms.KeyEventHandler(this.cmbMenuName_KeyDown);
            cmbMenuName.KeyUp += new System.Windows.Forms.KeyEventHandler(this.cmbMenuName_KeyUp);
            this.ResumeLayout(false);
        }
        private void Form2_Load(object sender, EventArgs e)
        {

         FillGrid(125);// Menu combobox in Quotation Menu Grid
        }
        #region Variables

        Hashtable hash;
        private String[] _values;

        private ListBox _listBox;
        private bool _isAdded;
        private String _formerValue = String.Empty;
        #endregion Variables
       


        public DataTable FillGrid(int QueryNo)
        {
            try
            {
                hash = new Hashtable();
                DataTable dtReturn = new DataTable();
                hash.Add("@QueryNo", QueryNo);

                //dtReturn= ClsDefination.FillData()
                dtReturn = ClsDefination.FillData("[usp_Transaction_QuotationMaster_Select]", hash);


                if ((dtReturn != null && dtReturn.Rows.Count > 0))// || dtReturn2 != null && dtReturn2.Rows.Count > 0)
                {
                    DataRow objRow = dtReturn.Rows[0];
                    if (QueryNo == 125) // Menu Name
                    {
                        cmbMenuName.DataSource = dtReturn;
                        cmbMenuName.DisplayMember = "MenuName";
                        cmbMenuName.ValueMember = "MenuID";
                        cmbMenuName.Text = "";
                        List<string> list = new List<string>();
                        for (int i = 0; i < dtReturn.Rows.Count; i++)
                        {
                            DataRow dr=dtReturn.Rows[i];
                            
                            
                                list.Add(dr["MenuName"].ToString());
                           
                           
                           
                        }
                        _values = list.ToArray();
                    }

                }

                else
                {


                }
                return null;
            }
            catch (Exception)
            {
                return null;
                throw;
            }
        }

        private void cmbMenuName_KeyDown(object sender, KeyEventArgs e)
        {
            //react the arrow up and down
            switch (e.KeyCode)
            {
                case Keys.Down:
                    {
                        if ((_listBox.Visible) && (_listBox.SelectedIndex < _listBox.Items.Count - 1))
                        {
                            _listBox.SelectedIndex++;
                        }
                        break;
                    }
                case Keys.Up:
                    {
                        if ((_listBox.Visible) && (_listBox.SelectedIndex > 0))
                        {
                            _listBox.SelectedIndex--;
                        }
                        break;
                    }
            }
        }

        private void cmbMenuName_KeyUp(object sender, KeyEventArgs e)
        {
            //whenever a key is pressed, update the listbox content
            UpdateListBox();
        }


        private void _listBox_MouseDown(object sender, MouseEventArgs e)
        {
            //select the item with the mouse
            if (_listBox.Visible)
            {
                InsertWord((String)_listBox.SelectedItem);
                HideListBox();
                _formerValue = cmbMenuName.Text;
            }
        }


        private void HideListBox()
        {
            //Hide the listbox
            _listBox.Visible = false;
        }
        //private void btnShow_Click(object sender, EventArgs e)
        //{
        //    //when this button is clicked, 
        //    //we take the values from the textbox and list them into the second listbox
        //    lstSelectedValues.Items.Clear();
        //    List<String> selectedValues = SelectedValues;
        //    Array.ForEach(selectedValues.ToArray(),
        //                  selectedValue => lstSelectedValues.Items.Add(selectedValue.Trim()));
        //}
        public List<String> SelectedValues
        {
            get
            {
                //return the list of selection
                String[] result = cmbMenuName.Text.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
                return new List<String>(result);
            }
        }
        private void UpdateListBox()
        {
            //fill the listbox with the new filtered values
            if (cmbMenuName.Text != _formerValue)
            {
                _formerValue = cmbMenuName.Text;
                String word = GetWord();

                if (word.Length > 0)
                {
                    //case insensitive search
                    String[] matches = Array.FindAll(_values, x => (x.ToUpper().Contains(word.ToUpper()) && !SelectedValues.Contains(x)));
                    if (matches.Length > 0)
                    {
                        ShowListBox();
                        _listBox.Items.Clear();
                        Array.ForEach(matches, x => _listBox.Items.Add(x));
                        _listBox.SelectedIndex = 0;
                        _listBox.Height = 0;
                        //at least the same width as the textbox
                        _listBox.Width = cmbMenuName.Width;
                      //  cmbMenuName.Focus();
                        using (Graphics graphics = _listBox.CreateGraphics())
                        {
                            for (int i = 0; i < _listBox.Items.Count; i++)
                            {
                                _listBox.Height += _listBox.GetItemHeight(i);
                                // it item width is larger than the current one
                                // set it to the new max item width
                                // GetItemRectangle does not work for me
                                // we add a little extra space by using '_'
                                int itemWidth = (int)graphics.MeasureString(((String)_listBox.Items[i]) + "_", _listBox.Font).Width;
                                _listBox.Width = (_listBox.Width < itemWidth) ? itemWidth : _listBox.Width;
                            }
                        }
                    }
                    else
                    {
                        HideListBox();
                    }
                }
                else
                {
                    HideListBox();
                }
            }
        }


        private void ShowListBox()
        {
            //display the listbox just below the textbox
            if (!_isAdded)
            {
                this.Controls.Add(_listBox);
                _listBox.Left = cmbMenuName.Left;
                _listBox.Top = cmbMenuName.Top + cmbMenuName.Height;
                _isAdded = true;
            }
            _listBox.Visible = true;
        }



        private String GetWord()
        {
            //get the current word (useful when there is more than one on the textbox)
            String text = cmbMenuName.Text;
            int pos = cmbMenuName.SelectionStart;

            int posStart = text.LastIndexOf(';', (pos < 1) ? 0 : pos - 1);
            posStart = (posStart == -1) ? 0 : posStart + 1;
            int posEnd = text.IndexOf(';', pos);
            posEnd = (posEnd == -1) ? text.Length : posEnd;

            int length = ((posEnd - posStart) < 0) ? 0 : posEnd - posStart;

            return text.Substring(posStart, length);
        }

        private void InsertWord(String newTag)
        {
            //add the new selection to the textbox
            String text = cmbMenuName.Text;
            int pos = cmbMenuName.SelectionStart;

            int posStart = text.LastIndexOf(';', (pos < 1) ? 0 : pos - 1);
            posStart = (posStart == -1) ? 0 : posStart + 1;
            int posEnd = text.IndexOf(';', pos);

            String firstPart = text.Substring(0, posStart) + newTag;
            String updatedText = firstPart + ((posEnd == -1) ? "" : text.Substring(posEnd, text.Length - posEnd));


            cmbMenuName.Text = updatedText;
            cmbMenuName.SelectionStart = firstPart.Length;
        }

        private void cmbMenuName_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
        {
            if ((e.KeyCode == Keys.Tab) && (_listBox.Visible))
            {
                InsertWord((String)_listBox.SelectedItem);
                HideListBox();
                _formerValue = cmbMenuName.Text;
            }
        }




    }
}