/// <summary>
/// for TextBox 
/// </summary>
public class IMYansSuggest<TEntity> where TEntity : class
{
    #region events

public delegate void OnConfirmHandler(TEntity entity);
    public event OnConfirmHandler OnConfirm;

#endregion

#region private controls

TextBox iwin;
    Panel panel;
    DataGridView dgv;

#endregion

List<TEntity> lstData;
    public IMYansSuggest(TextBox IWin) {
        iwin = IWin;
        bindWin();
    }

public IMYansSuggest(TextBox IWin, List<TEntity> lstdata) {
        iwin = IWin;
        lstData = lstdata;
        bindWin();
        InitializeComponent();
    }
         
    /// <summary>
    /// 设置数据源
    /// </summary>
    /// <param name="lstdata"></param>
    public void SetCustomDataSource(List<TEntity> lstdata) {
        lstData = lstdata;
        InitializeComponent();
    }

List<string> showColumns = new List<string>();
    /// <summary>
    /// 设置显示字段
    /// </summary>
    /// <param name="column">显示字段</param>
    public void SetShowColumns(params string[] column) {
        showColumns = column.ToList();
    }

/// <summary>
    /// 获取显示字段
    /// </summary>
    /// <returns></returns>
    public List<string> GetShowColumns() {
        if (showColumns.Count > 0)
            return showColumns;
        return typeof(TEntity).GetProperties(System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public).Select(Y => Y.Name).ToList();
    }

string enterColumn = string.Empty;
    /// <summary>
    /// 设置填入文本信息
    /// </summary>
    /// <param name="columnName"></param>
    public void SetEnterColumnName(string columnName) {
        enterColumn = columnName;
    }

void InitializeComponent() {
        if (null == dgv) {
            dgv = new DataGridView();
            dgv.AutoGenerateColumns = false;
            panel = new Panel();
            panel.Controls.Add(dgv);
            dgv.Dock = DockStyle.Fill;
            panel.Visible = false;
            iwin.Parent.Controls.Add(panel);

panel.Top = iwin.Top + iwin.Height;
            panel.Left = iwin.Left;

foreach (var v in GetShowColumns()) {
                var dc = new DataGridViewTextBoxColumn();
                dc.DataPropertyName = v;
                dc.Name = v;
                dgv.Columns.Add(dc);
            }
            dgv.DataSource = lstData;

panel.BringToFront();
            dgv.RowHeadersVisible = false;
            dgv.RowTemplate.Height = 18;
            dgv.ColumnHeadersVisible = false;
            dgv.AllowUserToDeleteRows = false;
            dgv.AllowUserToAddRows = false;
            dgv.AllowUserToResizeColumns = false;
            dgv.AllowUserToResizeRows = false;

dgv.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
            dgv.MultiSelect = false;
            dgv.TabStop = false; 
            panel.HorizontalScroll.Enabled = false;
            panel.Width = dgv.Columns.Cast<DataGridViewColumn>().Sum(Y => Y.Width) + 20;

dgv.LostFocus += new EventHandler(IWin_LostFocus);
            dgv.CellDoubleClick += new DataGridViewCellEventHandler(dgv_CellDoubleClick);
        }
    }

void dgv_CellDoubleClick(object sender, DataGridViewCellEventArgs e) {
        if (e.RowIndex > -1) {
            SetIWinValue((TEntity)dgv.CurrentRow.DataBoundItem);
            iwin.SelectAll();
        }
    }

void bindWin() {
        iwin.TextChanged += new EventHandler(IWin_TextChanged);
        iwin.LostFocus += new EventHandler(IWin_LostFocus);
        iwin.GotFocus += new EventHandler(iwin_GotFocus);
        iwin.MouseWheel += new MouseEventHandler(iwin_MouseWheel);
        iwin.KeyDown += new KeyEventHandler(iwin_KeyDown);
    }

void iwin_KeyDown(object sender, KeyEventArgs e) {
        if (e.KeyCode == Keys.Up) {
            scrollUp();
        }
        else if (e.KeyCode == Keys.Down) {
            scrollDown();
        }
        else if (e.KeyCode == Keys.Enter) {
            if (null != dgv.CurrentRow) {
                SetIWinValue((TEntity)dgv.CurrentRow.DataBoundItem);
            }
        }
    }

public string GetShowColumn() {
        if (enterColumn.Length > 0)
            return enterColumn;
        return typeof(TEntity).GetProperties(System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public)[0].Name;
    }

void SetIWinValue(TEntity entity) {
        if (null != OnConfirm) {
            OnConfirm(entity);
        }
        else {
            iwin.Text = typeof(TEntity).GetProperty(GetShowColumn()).GetValue(entity, null).ToString();
        }
    }

/// <summary>
    /// 鼠标滚动
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    void iwin_MouseWheel(object sender, MouseEventArgs e) {
        if (e.Delta > 0) {
            scrollUp();
        }
        else if (e.Delta < 0) {
            scrollDown();
        }
    }

/// <summary>
    /// 获得焦点
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    void iwin_GotFocus(object sender, EventArgs e) {
        if (null != dgv) {
            panel.Visible = true;
        }
        iwin.SelectAll();
    }

/// <summary>
    /// 失去焦点
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    void IWin_LostFocus(object sender, EventArgs e) {
        if (null != dgv && dgv.Visible && !dgv.Focused && !iwin.Focused) {
            panel.Visible = false;
        }
    }

void scrollUp() {
        if (null == dgv.CurrentRow) {
            dgv.ClearSelection();
            dgv.Rows[0].Selected = true;
            dgv.CurrentCell = dgv.Rows[0].Cells[0];
        }
        else {
            var index = dgv.SelectedRows[0].Index;
            if (index > 0) {
                dgv.ClearSelection();
                dgv.Rows[index - 1].Selected = true;
                dgv.CurrentCell = dgv.Rows[index - 1].Cells[0];
            }
        }
    }

void scrollDown() {
        if (null == dgv.CurrentRow) {
            dgv.ClearSelection();
            dgv.Rows[0].Selected = true;
            dgv.CurrentCell = dgv.Rows[0].Cells[0];
        }
        else {
            var index = dgv.SelectedRows[0].Index;
            if (index != dgv.Rows.Count - 1) {
                dgv.ClearSelection();
                dgv.Rows[index + 1].Selected = true;
                dgv.CurrentCell = dgv.Rows[index + 1].Cells[0];
            }
        }
    }

/// <summary>
    /// 文本改变
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    void IWin_TextChanged(object sender, EventArgs e) {
        bool isFinded = false;
        for (int i = 0; i < dgv.Rows.Count; i++) {
            var row = dgv.Rows[i];
            //                foreach (DataColumn dc in data.Columns) {
            foreach (var v in GetShowColumns()) {
                if (row.Cells[v].Value.ToString().StartsWith(iwin.Text, true, System.Globalization.CultureInfo.InvariantCulture)) {
                    dgv.ClearSelection();
                    row.Selected = true;
                    dgv.CurrentCell = row.Cells[0];
                    isFinded = true;
                    break;
                }
            }
            if (isFinded) break;
        }
    }

}

public partial class frmMain : Form
{
    public frmMain() {
        InitializeComponent();
    }

private void frmMain_Load(object sender, EventArgs e) {

var lstPerson = new List<Person>();
        Random r = new Random();
        for (int i = 1; i < 100; i++) {
            lstPerson.Add(new Person {
                ID = i,
                Name = "yans" + i.ToString(),
                Age = r.Next(1, 100),
                Remark = "this just a remark for you."
            });
        }

new IMYansSuggest<Person>(textBox1, lstPerson);
    }
}

class Person
{
    public int ID { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public string Remark { get; set; }
}