OpenTween.TweenMain.DrawListViewItemIcon C# (CSharp) Method

        private void DrawListViewItemIcon(DrawListViewItemEventArgs e)
        {
            if (_iconSz == 0) return;

            ImageListViewItem item = (ImageListViewItem)e.Item;

            //e.Bounds.Leftが常に0を指すから自前で計算
            Rectangle itemRect = item.Bounds;
            var col0 = e.Item.ListView.Columns[0];
            itemRect.Width = col0.Width;

            if (col0.DisplayIndex > 0)
            {
                foreach (ColumnHeader clm in e.Item.ListView.Columns)
                {
                    if (clm.DisplayIndex < col0.DisplayIndex)
                        itemRect.X += clm.Width;
                }
            }

            // ディスプレイの DPI 設定を考慮したアイコンサイズ
            var realIconSize = new SizeF(this._iconSz * this.CurrentScaleFactor.Width, this._iconSz * this.CurrentScaleFactor.Height).ToSize();
            var realStateSize = new SizeF(16 * this.CurrentScaleFactor.Width, 16 * this.CurrentScaleFactor.Height).ToSize();

            Rectangle iconRect;
            var img = item.Image;
            if (img != null)
            {
                iconRect = Rectangle.Intersect(new Rectangle(e.Item.GetBounds(ItemBoundsPortion.Icon).Location, realIconSize), itemRect);
                iconRect.Offset(0, Math.Max(0, (itemRect.Height - realIconSize.Height) / 2));

                if (iconRect.Width > 0)
                {
                    e.Graphics.FillRectangle(Brushes.White, iconRect);
                    e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                    try
                    {
                        e.Graphics.DrawImage(img.Image, iconRect);
                    }
                    catch (ArgumentException)
                    {
                        item.RefreshImageAsync();
                    }
                }
            }
            else
            {
                iconRect = Rectangle.Intersect(new Rectangle(e.Item.GetBounds(ItemBoundsPortion.Icon).Location, new Size(1, 1)), itemRect);
                //iconRect.Offset(0, Math.Max(0, (itemRect.Height - realIconSize.Height) / 2));

                item.GetImageAsync();
            }

            if (item.StateIndex > -1)
            {
                Rectangle stateRect = Rectangle.Intersect(new Rectangle(new Point(iconRect.X + realIconSize.Width + 2, iconRect.Y), realStateSize), itemRect);
                if (stateRect.Width > 0)
                {
                    //e.Graphics.FillRectangle(Brushes.White, stateRect);
                    //e.Graphics.InterpolationMode = Drawing2D.InterpolationMode.High;
                    e.Graphics.DrawImage(this.PostStateImageList.Images[item.StateIndex], stateRect);
                }
            }
        }