/// <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);
}