/// <summary>
    /// 将图像路径集合转为位图列表。
    /// </summary>
    /// <param name="imagePaths">给定的 <see cref="IEnumerable{String}"/>。</param>
    /// <returns>返回 <see cref="IBitmapList"/>。</returns>
    public static IBitmapList AsBitmaps(this IEnumerable <string> imagePaths)
    {
        var bitmaps = new BitmapList();

        bitmaps.Add(imagePaths);

        return(bitmaps);
    }
    /// <summary>
    /// 将图像路径转为位图列表。
    /// </summary>
    /// <param name="imagePath">给定的图像路径。</param>
    /// <returns>返回 <see cref="IBitmapList"/>。</returns>
    public static IBitmapList AsBitmaps(this string imagePath)
    {
        var bitmaps = new BitmapList();

        bitmaps.Add(imagePath);

        return(bitmaps);
    }
    protected override IBitmapList DrawCore(IBitmapList bitmaps)
    {
        if (Options.Scale.Descriptors.Count < 1)
        {
            return(bitmaps);
        }

        var scaleBitmaps     = new BitmapList();
        var watermarkBitmaps = new BitmapList();

        foreach (var bitmap in bitmaps)
        {
            var realBitmap = (SKBitmap)bitmap.Source;
            // 遍历缩放信息
            foreach (var scaleDescriptor in Options.Scale.Descriptors)
            {
                // 如果源图尺寸小于缩放尺寸,则跳过当前缩放信息
                if (realBitmap.Width <= scaleDescriptor.MaxSize.Width &&
                    realBitmap.Height <= scaleDescriptor.MaxSize.Height)
                {
                    continue;
                }

                // 计算等比例缩放尺寸
                var imageSize = new Size(realBitmap.Width, realBitmap.Height);
                var scaleSize = ImageHelper.ScaleSize(imageSize, scaleDescriptor.MaxSize);
                var scaleInfo = new SKImageInfo(scaleSize.Width, scaleSize.Height,
                                                realBitmap.Info.ColorType, realBitmap.Info.AlphaType);

                // 是否附加缩放尺寸后缀
                var scaleNameFuffix = scaleDescriptor.FileNameSuffix;
                if (Options.Scale.AddScaleSizeSuffix)
                {
                    scaleNameFuffix += $"-{scaleSize.Width}x{scaleSize.Height}";
                }

                // 创建缩放位图描述符
                var scaleBitmap = realBitmap.Resize(scaleInfo, Options.ResizeQuality);
                var descriptor  = new BitmapDescriptor(scaleBitmap, bitmap.FilePath,
                                                       scaleNameFuffix);

                scaleBitmaps.Add(descriptor);

                if (scaleDescriptor.AddWatermark)
                {
                    watermarkBitmaps.Add(descriptor);
                }
            }
        }

        // 处理缩放位图集合的水印
        if (watermarkBitmaps.Count > 0)
        {
            _watermarkDrawer.Draw(watermarkBitmaps);
        }

        return(scaleBitmaps);
    }