/// <summary>
/// 获取指定图片的缩略（指定大小）
/// </summary>
/// <remarks>@FrancisTan 2016-05-17</remarks>
/// <param name="imgStream">图片二进制流</param>
/// <param name="width">缩略图宽度</param>
/// <param name="height">缩略图宽度</param>
/// <param name="quality">图片质量百分比，它必须是0~100之间的整数</param>
/// <exception cref="ArgumentNullException">图片文件流为空</exception>
/// <returns>缩略图二进制流</returns>
public static Stream GetThumbnailStream(Stream imgStream, int width, int height, int quality)
{
if (imgStream == null || imgStream.Length == 0)
{
throw new ArgumentNullException("imgStream");
}
if (width <= 0)
{
throw new ArgumentOutOfRangeException("width", "图片宽度必须大于0");
}
if (height <= 0)
{
throw new ArgumentOutOfRangeException("height", "图片高度必须大于0");
}
if (quality <= 0 || quality > 100)
{
throw new ArgumentOutOfRangeException("quality", "图片质量百分比须在0~100之间");
}
// Format is automatically detected though can be changed.
ISupportedImageFormat format = new PngFormat();
Size size = new Size(width, height);
using (ImageFactory factory = new ImageFactory(preserveExifData: true))
{
factory.Load(imgStream)
.Format(format);
var scaling = GetScaling(factory.Image.Size, size);
var scaleSize = GetScaleSize(factory.Image.Size, scaling);
factory.Constrain(scaleSize);
return(CropAroundCenterPoint(factory, size));
}
}
private static Stream CompressImage(ImageFactory imgfactory, string imageFile)
{
MemoryStream memStream;
var quality = Options.Quality;
imgfactory.Load(imageFile);
if (Options.Scale != 1)
{
imgfactory.Constrain(new Size((int)(imgfactory.Image.Size.Height * Options.Scale),
(int)(imgfactory.Image.Size.Width * Options.Scale)));
}
do
{
memStream = new MemoryStream();
imgfactory
.Quality(quality--)
.Save(memStream);
} while (((memStream.Length > Options.MaxImageSize * 1024) && quality > 0) && Options.MaxImageSize != 0);
if (quality == 0)
{
imgfactory
.Quality(Options.Quality)
.Save(memStream);
}
return(memStream);
}
/// <summary>
/// Performs the Constrain effect from the ImageProcessor library.
/// </summary>
/// <param name="image">The image with which to apply the effect.</param>
/// <param name="size">The size with which the Constrain effect will be applied.</param>
/// <returns>A new image with the Constrain effect applied.</returns>
public Image Constrain(Image image, Size size)
{
using var factory = new ImageFactory();
factory.Load(image);
factory.Constrain(size);
var result = factory.Image;
return(new Bitmap(result));
}
// GET: Media
public ActionResult Cache(String slug, String format, String filename)
{
String cacheFilename = Server.MapPath(String.Format("~/App_Data/media/{0}/{1}/{2}", slug, format, filename));
String remoteFilename = String.Format("https://robertsspaceindustries.com/media/{0}/{1}/{2}", slug, "source", filename);
if (!System.IO.File.Exists(cacheFilename))
{
if (!System.IO.Directory.Exists(Path.GetDirectoryName(cacheFilename)))
{
System.IO.Directory.CreateDirectory(Path.GetDirectoryName(cacheFilename));
}
using (WebClient client = new WebClient())
{
using (Stream stream = client.OpenRead(remoteFilename))
{
using (MemoryStream inStream = new MemoryStream())
{
stream.CopyTo(inStream);
using (ImageFactory factory = new ImageFactory())
{
factory.Load(inStream);
String[] parts = format.Split('x');
if (parts.Length != 2)
{
parts = new String[] { "800", "600" };
}
factory.Constrain(new System.Drawing.Size
{
Height = parts[1].ToInt32(600),
Width = parts[0].ToInt32(800)
});
// , new System.Drawing.Point
// {
// X = factory.Image.Width / 2,
// Y = factory.Image.Height / 2
// });
if (Path.GetExtension(cacheFilename) == "jpg")
{
using (FileStream outStream = new FileStream(cacheFilename, FileMode.Create))
{
factory.Optimize(outStream);
}
}
else
{
factory.Save(cacheFilename);
}
}
}
}
}
}
String contentType = MimeMapping.GetMimeMapping(cacheFilename);
this.Response.Cache.SetCacheability(HttpCacheability.Public);
this.Response.Cache.SetExpires(DateTime.Today.AddDays(7));
this.Response.Cache.SetMaxAge(TimeSpan.FromHours(168));
return(File(cacheFilename, contentType));
}
