protected override void ProcessRequestCore(System.Web.HttpContext context)
{
HttpResponse response = context.Response;
response.Clear();
try
{
if (this.CheckAccessRight(context))
{
MemoryStream mStream = null;
using (Stream stream = this.GetFileStream(context))
{
ThumbImageViewer.CopyStream(mStream, stream);
}
long startPosition = this.GetStartPosition(context);
this.AddHeader(context, mStream, startPosition);
this.ResponseStream(context, mStream, startPosition);
}
}
finally
{
//response.End();
}
}
protected virtual void ThumbImage(HttpContext context)
{
string fileName = this.FileID;
if (!string.IsNullOrEmpty(fileName))
{
int width = 0;
int height = 0;
GetImageSize(out width, out height);
Guid fileID = FileGuid;
SetResponseContentType(context);
SetResponseHeader(context);
Stream imageStream = null;
LogicFileInfoData fileInfo = FileManager.GetFileInfo(fileID);
//先看缓存目录里有没有
string thumbImageDirPath = context.Server.MapPath("~/ThumbImage");
string thumbImagePath = Path.Combine(thumbImageDirPath, string.Format("{0}_{1}_{2}{3}", FileGuid, width, height, fileInfo.LogicFileExt));
if (!Directory.Exists(thumbImageDirPath))
{
Directory.CreateDirectory(thumbImageDirPath);
}
if (File.Exists(thumbImagePath))
{
try
{
imageStream = File.OpenRead(thumbImagePath);
OutputStream(context, imageStream);
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (imageStream != null)
{
imageStream.Dispose();
}
}
}
else
{
try
{
using (Stream stream = FileManager.OpenReadFile(fileID))
{
imageStream = new MemoryStream();
ThumbImageViewer.CopyStream(imageStream, stream);
}
if (width <= 0 || height <= 0)
{
OutputStream(context, imageStream);
}
else
{
using (MemoryStream bufferOutput = new MemoryStream())
{
ThumbImageViewer.OutputImage(bufferOutput, imageStream, this.ClientFileID, width, height, img =>
{
//保存缩列图缓存
if (img != null)
{
try
{
img.Save(thumbImagePath);
}
catch (Exception ex)
{
throw ex;
}
}
});
if (bufferOutput.Length > 0)
{
bufferOutput.Position = 0;
OutputStream(context, bufferOutput);
}
}
}
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (imageStream != null)
{
imageStream.Dispose();
}
}
}
}
}
private void OutputStream(HttpContext context, Stream inStream)
{
HttpResponse response = context.Response;
ThumbImageViewer.CopyStream(response.OutputStream, inStream);
}
