WinForms ControlExtensions Parents() AndParents()

ControlExtensions.c

using System.Windows.Forms;
using System.Collections.Generic;

namespace System.Windows.Forms.Extensions
{
    /// <summary>
    /// コントロールの拡張関数クラス
    /// </summary>
    public static class ControlExtension
    {
        /// <summary>
        /// 自分の親を返す
        /// </summary>
        /// <param name="self"></param>
        /// <returns></returns>
        public static IEnumerable<Control> Parents(this Control self)
        {
            if (self == null)
                yield break;
            var c = self;
            while((c = c.Parent) != null)
            {
                yield return c;
            }
        }
        /// <summary>
        /// 自分を含めた自分の親を返す
        /// </summary>
        /// <param name="self"></param>
        /// <returns></returns>
        public static IEnumerable<Control> AndParents(this Control self)
        {
            if (self == null)
                yield break;
            var c = self;
            do
            {
                yield return c;
            } while ((c = c.Parent) != null);
        }
    }
}

例えば、Form(=this) 上のcontrol の親子関係とか考えずにそのRectangle表現が欲しいならこうする

var rectangle = new Rectangle(control
    .AndParents()
    .TakeWhile(c => c!= this)
    .Select(c => c.Location)
    .Aggregate(new Point(0,0), (p. l) => {
        p.X += l.X;
        p.Y += l.Y;
        return p;
    }, control.Size);