使用 ajax 调用 MVC 从数据库下载文件

Question

I'm trying to implement file download functionality thru ajax call in MVC. After calling of controller method i always have a "parseerror", can somebody explain me why?

my ajax:

tab.on("click", ".FileDownload", function (e) {

    //$('#uploadStatus').html("ok");
    var tr = $(this).closest("tr");
    var id = tr.data("id");

    $.ajax({
        type: "POST",
        url: "/File/FileDownload",
        //contentType: false,
        //processData: false,
        //dataType: "json",
        data: { fileId: id },
        success: function (data) {
            $('#uploadStatus').html("ok");
        },
        error: function (err) {
            alert(err.statusText);
        }
    });

});

and controller:

[HttpPost]
    public FileResult FileDownload(int? fileId)
    {

        FileDBEntities db = new FileDBEntities();
        tblFile file = db.tblFiles.ToList().Find(p => p.id == fileId.Value);
        return File(file.Data, file.ContentType, file.Name);
    }

with simple download link in razor it works, but not with ajax. What am I doing wrong here?

Answer 1

Why not simple use

tab.on("click", ".FileDownload", function (e) {

    //$('#uploadStatus').html("ok");
    var tr = $(this).closest("tr");
    var id = tr.data("id");

    window.location = window.location.origin + '/File/FileDownload?fileId=' + id;

});

[HttpGet]
    public FileResult FileDownload(int? fileId)