How to use web handlers for PDF creation?

问题:

I have pretty less knowledge in web handlers. All I know is web handlers are used for creating some dynamic file creation purpose.

And also I know how to add the Web handlers.

But, I need to use web handlers in my ASP.NET project for PDF creation purpose.

回答1:

You can have a HTTP handler to serve out your PDFs like this:

public void ProcessRequest (HttpContext context) {

    // Get your file as byte[]
    string filename = "....file name.";
    byte[] data = get your PDF file content here;

    context.Response.Clear();
    context.Response.AddHeader("Pragma", "public");
    context.Response.AddHeader("Expires", "0");
    context.Response.AddHeader("Content-Type", ContentType);
    context.Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}", filename));
    context.Response.AddHeader("Content-Transfer-Encoding", "binary");
    context.Response.AddHeader("Content-Length", data.Length.ToString());
    context.Response.BinaryWrite(data);
    context.Response.End(); 

}

回答2:

Read What is an HttpHandler in ASP.NET and MSDN: HTTP Handlers and HTTP Modules Overview.

You do not need a handler to serve files for downloading over HTTP. You can also generate and return a file response in a WebForms page, as well as from ASP.NET MVC and WebAPI.

Depending on the technology you use, check out:

• HTTP handler: ASP.NET add a httphandler to edit downloaded file name, Dynamically create JS file using ASP.net Handler, MSDN: Serving Dynamic Content with HTTP Handlers
• WebForms page: .NET MVC FileResult equivalent in Web Forms
• ASP.NET MVC: Download file of any type in Asp.Net MVC using FileResult?
• WebAPI: Returning binary file from controller in ASP.NET Web API

Of course, any layer on top of a handler (as opposed to running your code from a handler directly) adds additional overhead (though it'll be minimal), where I suspect WebForms to be the heaviest. MVC and WebAPI are run through the MvcHandler.