问题
I'm using Debenu PDF Library to extract pages from a pdf file. Here is how I do it,
var pdflib = new PDFLibrary(LoadDll());
int result = pdflib.UnlockKey("UNLOCKKEYISHERE");
AzureStorageWrapper sasWrapper = new AzureStorageWrapper(ConfigurationManager.AppSettings["AzureStorageConnection"], "cont1");
byte[] blob = sasWrapper.GetBlob("file.pdf");
pdflib.LoadFromString(blob, "");
byte[] page = pdflib.RenderPageToString(50, 1, 1);
When I run this on my local machine it works perfectly (first page of the PDF file comes to the page byte array).
But after publishing this as an Azure Web App page gets a some useless string of bytes.
Can anyone explain to me why this is?
回答1:
You've hit an Azure App Service sandbox runtime exectution limitation.
From https://github.com/projectkudu/kudu/wiki/Azure-Web-App-sandbox#unsupported-frameworks:
Unsupported frameworks
Here is a list of frameworks and scenarios that have been found to be not be usable due to one or more of the restrictions above. It's conceivable that some will be supported in the future as the sandbox evolves.
PDF generators failing due to restriction mentioned above:
EVOPDF
Rotativa
wkhtmltopdf
Syncfusion
Siberix
NReco (uses wkhtmltopdf)
Spire.PDFOther scenarios:
PhantomJS/Selenium: tries to connect to local address, and also uses GDI+.
It's probably safe to say you can add Debenu PDF to that list.
There is however a mention that some GDI calls may work on Basic/Standard pricing tiers in App Service. It's worth giving that a go if you're currently on Free/Shared.
Alternatives to App Service for running stuff that uses GDI/GDI+:
- A Web/Worker Role (Cloud Services)
- Service Fabric
- IaaS Virtual Machine
Similar question here: What could cause EvoPDF "unable to render html" exception when deployed to Azure Website
来源：https://stackoverflow.com/questions/38563426/debenu-pdf-works-on-localhost-fails-on-azure