ABADev blog

var
  dbl: Double;
  dt: TDateTime;
begin
  dbl := 65985.3333;
  dt := dbl;
end;

  Double dbl = 65985.3333;
  DateTime dt = DateTime.FromOADate(dbl)

using System; 
using System.Windows.Forms; 
 
public class CalendarColumn : DataGridViewColumn 
{ 
    public CalendarColumn() : base(new CalendarCell()) 
    { 
    } 
    public override DataGridViewCell CellTemplate 
    { 
        get 
        { 
            return base.CellTemplate; 
        } 
        set 
        { 
            // Ensure that the cell used for the template is a CalendarCell. 
            if (value != null && 
                !value.GetType().IsAssignableFrom(typeof(CalendarCell))) 
            { 
                throw new InvalidCastException("Must be a CalendarCell"); 
            } 
            base.CellTemplate = value; 
        } 
    } 
} 
public class CalendarCell : DataGridViewTextBoxCell 
{ 
    public CalendarCell() 
        : base() 
    { 
        // Use the short date format. 
        this.Style.Format = "d"; 
    } 
    public override void InitializeEditingControl(int rowIndex, object 
        initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle) 
    { 
        // Set the value of the editing control to the current cell value. 
        base.InitializeEditingControl(rowIndex, initialFormattedValue, 
            dataGridViewCellStyle); 
        CalendarEditingControl ctl = 
            DataGridView.EditingControl as CalendarEditingControl; 
        ctl.Value = (DateTime)this.Value; 
    } 
    public override Type EditType 
    { 
        get 
        { 
            // Return the type of the editing contol that CalendarCell uses. 
            return typeof(CalendarEditingControl); 
        } 
    } 
    public override Type ValueType 
    { 
        get 
        { 
            // Return the type of the value that CalendarCell contains. 
            return typeof(DateTime); 
        } 
    } 
    public override object DefaultNewRowValue 
    { 
        get 
        { 
            // Use the current date and time as the default value. 
            return DateTime.Now; 
        } 
    } 
} 
class CalendarEditingControl : DateTimePicker, IDataGridViewEditingControl 
{ 
    DataGridView dataGridView; 
    private bool valueChanged = false; 
    int rowIndex; 
    public CalendarEditingControl() 
    { 
        this.Format = DateTimePickerFormat.Short; 
    } 
    // Implements the IDataGridViewEditingControl.EditingControlFormattedValue 
    // property. 
    public object EditingControlFormattedValue 
    { 
        get 
        { 
            return this.Value.ToShortDateString(); 
        } 
        set 
        { 
            if (value is String) 
            { 
                this.Value = DateTime.Parse((String)value); 
            } 
        } 
    } 
    // Implements the 
    // IDataGridViewEditingControl.GetEditingControlFormattedValue method. 
    public object GetEditingControlFormattedValue( 
        DataGridViewDataErrorContexts context) 
    { 
        return EditingControlFormattedValue; 
    } 
    // Implements the 
    // IDataGridViewEditingControl.ApplyCellStyleToEditingControl method. 
    public void ApplyCellStyleToEditingControl( 
        DataGridViewCellStyle dataGridViewCellStyle) 
    { 
        this.Font = dataGridViewCellStyle.Font; 
        this.CalendarForeColor = dataGridViewCellStyle.ForeColor; 
        this.CalendarMonthBackground = dataGridViewCellStyle.BackColor; 
    } 
    // Implements the IDataGridViewEditingControl.EditingControlRowIndex 
    // property. 
    public int EditingControlRowIndex 
    { 
        get 
        { 
            return rowIndex; 
        } 
        set 
        { 
            rowIndex = value; 
        } 
    } 
    // Implements the IDataGridViewEditingControl.EditingControlWantsInputKey 
    // method. 
    public bool EditingControlWantsInputKey( 
        Keys key, bool dataGridViewWantsInputKey) 
    { 
        // Let the DateTimePicker handle the keys listed. 
        switch (key & Keys.KeyCode) 
        { 
            case Keys.Left: 
            case Keys.Up: 
            case Keys.Down: 
            case Keys.Right: 
            case Keys.Home: 
            case Keys.End: 
            case Keys.PageDown: 
            case Keys.PageUp: 
                return true; 
            default: 
                return false; 
        } 
    } 
    // Implements the IDataGridViewEditingControl.PrepareEditingControlForEdit 
    // method. 
    public void PrepareEditingControlForEdit(bool selectAll) 
    { 
        // No preparation needs to be done. 
    } 
    // Implements the IDataGridViewEditingControl 
    // .RepositionEditingControlOnValueChange property. 
    public bool RepositionEditingControlOnValueChange 
    { 
        get 
        { 
            return false; 
        } 
    } 
    // Implements the IDataGridViewEditingControl 
    // .EditingControlDataGridView property. 
    public DataGridView EditingControlDataGridView 
    { 
        get 
        { 
            return dataGridView; 
        } 
        set 
        { 
            dataGridView = value; 
        } 
    } 
    // Implements the IDataGridViewEditingControl 
    // .EditingControlValueChanged property. 
    public bool EditingControlValueChanged 
    { 
        get 
        { 
            return valueChanged; 
        } 
        set 
        { 
            valueChanged = value; 
        } 
    } 
    // Implements the IDataGridViewEditingControl 
    // .EditingPanelCursor property. 
    public Cursor EditingPanelCursor 
    { 
        get 
        { 
            return base.Cursor; 
        } 
    } 
    protected override void OnValueChanged(EventArgs eventargs) 
    { 
        // Notify the DataGridView that the contents of the cell 
        // have changed. 
        valueChanged = true; 
        this.EditingControlDataGridView.NotifyCurrentCellDirty(true); 
        base.OnValueChanged(eventargs); 
    } 
} 
public class Form1 : Form 
{ 
    private DataGridView dataGridView1 = new DataGridView();
    [STAThreadAttribute()] 
    public static void Main() 
    { 
        Application.Run(new Form1()); 
    } 
    public Form1() 
    { 
        this.dataGridView1.Dock = DockStyle.Fill; 
        this.Controls.Add(this.dataGridView1); 
        this.Load += new EventHandler(Form1_Load); 
        this.Text = "DataGridView calendar column demo"; 
    } 
    private void Form1_Load(object sender, EventArgs e) 
    { 
        CalendarColumn col = new CalendarColumn(); 
        this.dataGridView1.Columns.Add(col); 
        this.dataGridView1.RowCount = 5; 
        foreach (DataGridViewRow row in this.dataGridView1.Rows) 
        { 
            row.Cells[0].Value = DateTime.Now; 
        } 
    } 
}

//Import cellcore.dll
 
[DllImport("cellcore.dll")]
 internal static extern int lineGetGeneralInfo(IntPtr hLine, byte[] bCache);
 
// code to get IMEI
private void getIMEIInfo()
{
string IMEI;
Tapi t = new Tapi();
t.Initialize();
Line _line = t.CreateLine(0, LINEMEDIAMODE.INTERACTIVEVOICE, LINECALLPRIVILEGE.MONITOR);
 
byte[] buffer = new byte[512];
//write size
BitConverter.GetBytes(512).CopyTo(buffer, 0);
 
if (lineGetGeneralInfo(_line.hLine, buffer) != 0)
{
throw new System.ComponentModel.Win32Exception(System.Runtime.InteropServices.Marshal.GetLastWin32Error(), "TAPI Error: " + System.Runtime.InteropServices.Marshal.GetLastWin32Error().ToString("X"));
}
 
int serialsize = BitConverter.ToInt32(buffer, 36);
int serialoffset = BitConverter.ToInt32(buffer, 40);
IMEI = System.Text.Encoding.Unicode.GetString(buffer, serialoffset, serialsize);
IMEI = IMEI.Substring(0, IMEI.IndexOf(Convert.ToChar(0)));
 
AppSettings.SetIMEI(IMEI);
_line.Dispose();
t.Shutdown();
}