在浏览器中使用ASP.NET MVC和C#显示或下载pdf

我读过很多关于这个的帖子，看起来很简单，但这让我发疯，我就是不明白为什么

我正在创建一个PDF文件，并试图显示它或下载它，但没有任何效果

这段代码显示了我的许多尝试，试图找出什么是错误的，但似乎没有什么是错误的

起初，我试图将PDF直接保存到流中，但由于它没有在浏览器中下载/显示，所以我将其保存到本地文件，并做了许多事情来确保一切正常

public ActionResult CreatePdfExport(string html)
{
    string stylesheet = System.IO.File.ReadAllText(Server.MapPath(@"~/Content/print.css"));

    PdfDocument pdf = CommonService.GetPdf(html, stylesheet);

    var ms = new MemoryStream();
    pdf.Save(ms, false); //save to stream
    ms.Flush();
    ms.Position = 0;

    using (var file = System.IO.File.OpenWrite(Server.MapPath(Path.Combine("~/Content/justcreated.pdf"))))
    ms.CopyTo(file);  //save to file to check if stream is good, and it is 

    MemoryStream msfromfile = new MemoryStream();

    using (FileStream filefromdisk = new FileStream(Server.MapPath(Path.Combine("~/Content/justcreated.pdf")), FileMode.Open, FileAccess.Read))
        filefromdisk.CopyTo(msfromfile);  //now get stream for file

    msfromfile.Position = 0;

    using (FileStream filetodisk = new FileStream(Server.MapPath(Path.Combine("~/Content/new.pdf")), FileMode.Create, System.IO.FileAccess.Write))
        msfromfile.CopyTo(filetodisk); //save to new file from new stream, all good, both files are good

    MemoryStream msfromfile2 = new MemoryStream();

    using (FileStream filefromdisk2 = new FileStream(Server.MapPath(Path.Combine("~/Content/justcreated.pdf")), FileMode.Open, FileAccess.Read))
        filefromdisk2.CopyTo(msfromfile2); //we now know the stream is good, we try to use it to respond

    // msfromfile2.Flush(); //this flush doesn't really affect, I get same invalid file with or without
    msfromfile2.Position = 0;

    // this is an attempt to try to return bytes directly, still same invalid file
    // return File(Server.MapPath(Path.Combine("~/Content/new.pdf")), "application/pdf");

    // invalid file, even if i set headers like content-type, content-disposition, nothing works
    return File(msfromfile2, "application/pdf", "pdf_downloaded.pdf");
}

我确实得到了类似PDF文件的响应数据，但它是无效的：

%PDF-1.4
%ÓôÌá
1 0 obj
<<
/CreationDate(D:20210407211253-06'00')
/Creator(PDFsharp 1.32.3057-g \(www.pdfsharp.net\))
/Producer(PDFsharp 1.32.3057-g \(www.pdfsharp.net\))
>>
endobj
2 0 obj
<<
/Type/Catalog
/Pages 3 0 R
>>
endobj
3 0 obj
<<
/Type/Pages
/Count 1
/Kids[4 0 R]
>>
endobj
4 0 obj
<<
etc
etc
etc

如果我尝试使用JavaScript打开，从数据响应创建blob，如下所示：

$scope.pdf = function () {
    var str_div = document.getElementById('information').innerHTML;
    growerReports.createPdf(str_div).then(function (response) {
        
        var file = new File([response.data], "mipdf.pdf", { type: "application/pdf" });
        var fileURL = URL.createObjectURL(file);

        $window.open(fileURL); //blank pdf
        $window.open("http://localhost:19260/Vendors/Content/justcreated.pdf"); //the pdf i want

    });
}

当我打开blob url时，我得到一个空白的pdf，这可能是因为pdf无效。文件的直接url将正确打开

所有这些都指向文件函数并没有返回我需要的内容，但这太奇怪了

return File(msfromfile2, "application/pdf", "pdf_downloaded.pdf")

因此，我尝试将ActionResult更改为

FileContentResult

和

FileStreamResult

，但它们都不起作用

我已经尝试了很多东西，所以我不知道还能尝试什么

也许我遗漏了一些非常简单的东西

return File(msfromfile2, "application/pdf", "pdf_downloaded.pdf")