All Answers

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Dynamic;
using System.Linq;
using Wisej.Web;

namespace MyApp.CustomControls {
    public class SearchComboBox : Wisej.Web.ComboBox {
        public int minLength { get; set; }
        public dynamic obj { get; set; }
        public string displayField { get; set; }
        public string valueField { get; set; }
        public bool limitToList { get; set; }
        public TextBox idTextBox { get; set; }
        public string defaultId { get; set; }
        public bool showInitialList { get; set; }
        public SearchComboBoxType searchType { get; set; }

        private string[] data { get; set; }
        private bool found { get; set; }

        public SearchComboBox() {
            this.KeyUp += SearchComboBox_KeyUp;
            this.TextChanged += SearchComboBox_TextChanged;
            this.Leave += SearchComboBox_Leave;
        }

        public void Set(dynamic ClassList, TextBox TextBoxForIdField, string DisplayItem, string IdItem = "", int MinimumLengthBeforeSearch = 2, bool LimitToList = true, bool ShowInitialList = true, string DefaultIdFieldValue = "0", SearchComboBoxType SearchComboBoxType = SearchComboBoxType.Contains){
            obj = ClassList;
            idTextBox = TextBoxForIdField;
            displayField = DisplayItem;
            if (IdItem == "") {
                valueField = DisplayItem;
            } else {
                valueField = IdItem;
            }
            minLength = MinimumLengthBeforeSearch;
            limitToList = LimitToList;
            defaultId = DefaultIdFieldValue;
            showInitialList = ShowInitialList;
            searchType = SearchComboBoxType;
            MakeTheMagicHappen();
        }

        public void MakeTheMagicHappen() {
            int cnt = obj.Count;
            data = new string[cnt];
            for (int i = 0; i < cnt; i++) {
                var changedItem = ToExpandoObject(obj[i]);
                var dictItem = changedItem as IDictionary<string, object>;
                data[i] = dictItem[displayField].ToString();
            }
            idTextBox.Text = defaultId;
            if (showInitialList) {
                ComboFill(obj, valueField, displayField);
            }
        }

        private void SearchComboBox_KeyUp(object sender, KeyEventArgs e) {
            if (e.KeyCode == Keys.Back) {
                int sStart = this.SelectionStart;
                if (sStart > 0) {
                    sStart--;
                    if (sStart == 0) {
                        this.Text = defaultId;
                    } else {
                        this.Text = this.Text.Substring(0, sStart);
                    }
                }
                e.Handled = true;
            }
        }

        private void SearchComboBox_TextChanged(object sender, EventArgs e) {
            HandleTextChanged();
            found = false;
            foreach (var o in obj) {
                if (o.Name == this.Text) {
                    idTextBox.Text = o.Id.ToString();
                    found = true;
                    break;
                }
            }
            if (!found) {
                idTextBox.Text = defaultId;
            }
        }

        private void HandleTextChanged() {
            var txt = this.Text;
            if (txt.Length > (minLength - 1)) {
                IEnumerable<string> list = null;
                switch (searchType) {
                    case SearchComboBoxType.Contains:
                        list = from d in data
                               where d.ToUpper().Contains(this.Text.ToUpper())
                               select d;
                        break;
                    case SearchComboBoxType.StartOnly:
                        list = from d in data
                               where d.ToUpper().StartsWith(this.Text.ToUpper())
                               select d;
                        break;
                    case SearchComboBoxType.EndOnly:
                        list = from d in data
                               where d.ToUpper().EndsWith(this.Text.ToUpper())
                               select d;
                        break;
                }
                if (list.Count() > 0) {
                    this.DataSource = list.ToList();
                    var sText = this.Items[0].ToString();
                    this.SelectionStart = txt.Length;
                    this.SelectionLength = sText.Length - txt.Length;
                    this.DroppedDown = true;
                    return;
                } else {
                    this.DroppedDown = false;
                    this.SelectionStart = txt.Length;
                }
            }
        }

        private void SearchComboBox_Leave(object sender, EventArgs e) {
            if (limitToList) {
                if (!found || idTextBox.Text == defaultId) {
                    this.Text = "";
                }
            }
        }

        // Helpers
        private ExpandoObject ToExpandoObject(object obj) {
            IDictionary<string, object> newObj = new ExpandoObject();
            foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(obj.GetType())) {
                newObj.Add(property.Name, property.GetValue(obj));
            }
            return (ExpandoObject)newObj;
        }

        private void ComboFill(IEnumerable<dynamic> dynObject, string valueField, string txtField = "") {
            List<KeyValuePair<string, string>> cboList = new List<KeyValuePair<string, string>>();
            if (dynObject != null && dynObject.Count() > 0) {
                cboList.Add(new KeyValuePair<string, string>(defaultId, ""));
                string dbFields = valueField;
                if (txtField != "") { dbFields += "," + txtField; }
                try {
                    foreach (dynamic item in dynObject) {
                        var changedItem = ToExpandoObject(item);
                        var dictItem = changedItem as IDictionary<string, object>;
                        string key = dictItem[valueField].ToString();
                        string value = key;
                        if (txtField != "") { value = dictItem[txtField].ToString(); }
                        cboList.Add(new KeyValuePair<string, string>(key, value));
                    }
                } catch {
                    // Well dammit - something didn't work!
                }
            } else {
                cboList.Add(new KeyValuePair<string, string>(valueField, txtField));
            }
            this.ValueMember = "key";
            this.DisplayMember = "value";
            this.DataSource = cboList;
        }

        public enum SearchComboBoxType {
            Contains = 0,
            StartOnly = 1,
            EndOnly = 2
        }
    }
}

Thank you for the sample.

Anchoring is currently not supported when hosted in a cell since there is no parent and the layout is managed by the client.

Docking is supported and works well.

AutoSize doesn’t seem to work because controls hosted in cells don’t have a parent. Will add a ticket. You can resolve it simply by adding Me.Size = Me.PreferredSize when you want the panel to autosize.

HTH