YearMonthEditor.cs

using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Calendar;
using DevExpress.XtraEditors.Controls;
using DevExpress.XtraEditors.Popup;
using DevExpress.XtraEditors.Repository;

DateTime MinDateTime = new DateTime(1900, 1, 1);
/// <summary>
/// 只顯示年月，且選擇時也只能選擇年月的 dateEdit
/// </summary>
public class YearMonthEdit : DateEdit
{
    private int _storedDate = 1;
    public int storedDate
    {
        get { return this._storedDate; }
        set { this._storedDate = value; }
    }

    public YearMonthEdit()
    {
        Properties.Mask.EditMask = "y";
        Properties.DisplayFormat.FormatString = "y";
        Properties.DisplayFormat.FormatType = DevExpress.Utils.FormatType.DateTime;
        Properties.EditFormat.FormatString = "y";
        Properties.EditFormat.FormatType = DevExpress.Utils.FormatType.DateTime;
    }
    
    public YearMonthEdit(DateEdit de) : this()
    {
        (de.Parent as System.Windows.Forms.Control).Controls.Add(this);
        Location = de.Location;
        Size = de.Size;
      
        if (de.DateTime == MinDateTime) EditValue = null;
        else DateTime = de.DateTime;
    }
  
    protected override PopupBaseForm CreatePopupForm()
    {
        return new YearMonthVistaPopupDateEditForm(this, _storedDate);
    }
    
    protected override void CreateRepositoryItem()
    {
        fProperties = new YearMonthRepositoryItemDateEdit(this);
    }
      
    private class YearMonthRepositoryItemDateEdit : RepositoryItemDateEdit
    {
        public YearMonthRepositoryItemDateEdit(DateEdit dateEdit)
        {
            SetOwnerEdit(dateEdit);
        }
        
        public override bool ShowToday
        {
            get{ return false; }
        }
    }
    
    private class YearMonthVistaPopupDateEditForm : VistaPopupDateEditForm
    {
        private int _storedDate { get; set; }
            
        public YearMonthVistaPopupDateEditForm(DateEdit ownerEdit, int storedDate) : base(ownerEdit)
        {
            this._storedDate = storedDate;
        }
            
        protected override DateEditCalendar CreateCalendar()
        {
            return new YearMonthVistaDateEditCalendar(OwnerEdit.Properties,OwnerEdit.EditValue, _storedDate);
        }
    }
    
    private class YearMonthVistaDateEditCalendar : VistaDateEditCalendar
    {
        private int _storedDate { get; set; }
        
        public YearMonthVistaDateEditCalendar(RepositoryItemDateEdit item, object editDate, int storedDate) : base(item, editDate)
        {
            _storedDate = storedDate;
        }
        
        protected override void Init()
        {
            base.Init();
            View = DateEditCalendarViewType.YearInfo;
        }
          
        protected override void OnItemClick(CalendarHitInfo hitInfo)
        {
            DayNumberCellInfo cell = (DayNumberCellInfo)hitInfo.HitObject;
            if (View == DateEditCalendarViewType.YearInfo)
            {
                DateTime date;
                if (_storedDate > 0) date = new DateTime(DateTime.Year, cell.Date.Month, _storedDate);
                else  date = DateTimeFuncs.LastDayOfMonth(new DateTime(DateTime.Year, cell.Date.Month, 1));
              
                OnDateTimeCommit(date, false);
            }
            else
            {
                base.OnItemClick(hitInfo);
            }
        }
    }
}

YearMonthFunctions.cs

using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Controls;
using DevExpress.XtraEditors.Repository;
using DevExpress.XtraGrid.Columns;

DateTime MinDateTime = new DateTime(1900, 1, 1);
/// <summary>
/// 讓指定的 DateEdit 只顯示年月，且選擇時也只能選擇年月。可指定儲存日期。
/// </summary>
/// <param name="de">指定的 DateEdit</param>
/// <param name="date">若為 -1 表示月底</param>
public static void SetYearMonth(DateEdit de, int date)
{
    YearMonthEdit deym = new YearMonthEdit(de);
    deym.storedDate = date;
    deym.Properties.NullDate = MinDateTime;
    de.Visible = false;
    de.Properties.NullDate = MinDateTime;
    de.EnabledChanged += (s, e) => deym.Enabled = de.Enabled;
    de.PropertiesChanged += (s, e) => deym.Properties.ReadOnly = de.Properties.ReadOnly;
    deym.EditValueChanged += (s, e) => de.EditValue = deym.EditValue;
}

/// <summary>
/// 設定 Girdcolumn 只顯示年月
/// </summary>
/// <param name="colDate">指定之 Girdcolumn</param>
public static void DisplayYearMonthFormat(GridColumn colDate)
{
    RepositoryItemDateEdit ride = new RepositoryItemDateEdit();

    ride.DisplayFormat.FormatString = "y";
    ride.DisplayFormat.FormatType = DevExpress.Utils.FormatType.DateTime;
    ride.EditFormat.FormatString = "y";
    ride.EditFormat.FormatType = DevExpress.Utils.FormatType.DateTime;
    ride.Mask.EditMask = "y";

    colDate.ColumnEdit = ride;
}