这是使用MVC时的工作代码，你从控制器中获取文件

假设你有你的字节数组声明和填充，你唯一需要做的是使用文件函数(使用System.Web.Mvc)

byte[] bytes = .... insert your bytes in the array
return File(bytes, System.Net.Mime.MediaTypeNames.Application.Octet, "nameoffile.exe");

然后，在同一个控制器中，添加这两个函数

protected override void OnResultExecuting(ResultExecutingContext context)
    {
        CheckAndHandleFileResult(context);

        base.OnResultExecuting(context);
    }

    private const string FILE_DOWNLOAD_COOKIE_NAME = "fileDownload";

    /// <summary>
    /// If the current response is a FileResult (an MVC base class for files) then write a
    /// cookie to inform jquery.fileDownload that a successful file download has occured
    /// </summary>
    /// <param name="context"></param>
    private void CheckAndHandleFileResult(ResultExecutingContext context)
    {
        if (context.Result is FileResult)
            //jquery.fileDownload uses this cookie to determine that a file download has completed successfully
            Response.SetCookie(new HttpCookie(FILE_DOWNLOAD_COOKIE_NAME, "true") { Path = "/" });
        else
            //ensure that the cookie is removed in case someone did a file download without using jquery.fileDownload
            if (Request.Cookies[FILE_DOWNLOAD_COOKIE_NAME] != null)
                Response.Cookies[FILE_DOWNLOAD_COOKIE_NAME].Expires = DateTime.Now.AddYears(-1);
    }

然后你将能够调用你的控制器来下载并获得"success"或"failure"回调

$.fileDownload(mvcUrl('name of the controller'), {
            httpMethod: 'POST',
            successCallback: function (url) {
            //insert success code

            },
            failCallback: function (html, url) {
            //insert fail code
            }
        });

如果你想使用jQuery文件下载，请注意这一点。 您需要重新设置响应，否则将无法下载

    //The IE will only work if you reset response
    getServletResponse().reset();
    //The jquery.fileDownload needs a cookie be set
    getServletResponse().setHeader("Set-Cookie", "fileDownload=true; path=/");
    //Do the reset of your action create InputStream and return

您的操作可以实现ServletResponseAware来访问getServletResponse()

在Rails中，我是这样做的:

function download_file(file_id) {
  let url       = '/files/' + file_id + '/download_file';
    $.ajax({
    type: 'GET',
    url: url,
    processData: false,
    success: function (data) {
       window.location = url;
    },
    error: function (xhr) {
     console.log(' Error:  >>>> ' + JSON.stringify(xhr));
    }
   });
 }

诀窍在于窗户。位置的部分。控制器的方法如下所示:

# GET /files/{:id}/download_file/
def download_file
    send_file(@file.file,
          :disposition => 'attachment',
          :url_based_filename => false)
end

可以肯定的是，您不能通过Ajax调用来实现这一点。

然而，有一个变通办法。

步骤:

如果你使用form.submit()下载文件，你可以这样做:

创建一个从客户端到服务器的ajax调用，并将文件流存储在会话中。 当从服务器返回“成功”时，调用form.submit()来处理存储在会话中的文件流。

当你想要决定是否需要在制作form.submit()后下载文件时，这是有帮助的，例如:在form.submit()上，在服务器端发生异常而不是崩溃的情况下，你可能需要在客户端显示一个自定义消息，在这种情况下，这个实现可能会有帮助。

你可以用HTML5

注意:返回的文件数据必须是base64编码的，因为JSON不能编码二进制数据

在我的AJAX响应中，我有一个看起来像这样的数据结构:

{
    result: 'OK',
    download: {
        mimetype: string(mimetype in the form 'major/minor'),
        filename: string(the name of the file to download),
        data: base64(the binary data as base64 to download)
    }
}

这意味着我可以执行以下操作来通过AJAX保存文件

var a = document.createElement('a');
if (window.URL && window.Blob && ('download' in a) && window.atob) {
    // Do it the HTML5 compliant way
    var blob = base64ToBlob(result.download.data, result.download.mimetype);
    var url = window.URL.createObjectURL(blob);
    a.href = url;
    a.download = result.download.filename;
    a.click();
    window.URL.revokeObjectURL(url);
}

函数base64ToBlob是从这里取的，必须按照这个函数使用

function base64ToBlob(base64, mimetype, slicesize) {
    if (!window.atob || !window.Uint8Array) {
        // The current browser doesn't have the atob function. Cannot continue
        return null;
    }
    mimetype = mimetype || '';
    slicesize = slicesize || 512;
    var bytechars = atob(base64);
    var bytearrays = [];
    for (var offset = 0; offset < bytechars.length; offset += slicesize) {
        var slice = bytechars.slice(offset, offset + slicesize);
        var bytenums = new Array(slice.length);
        for (var i = 0; i < slice.length; i++) {
            bytenums[i] = slice.charCodeAt(i);
        }
        var bytearray = new Uint8Array(bytenums);
        bytearrays[bytearrays.length] = bytearray;
    }
    return new Blob(bytearrays, {type: mimetype});
};

如果您的服务器正在转储要保存的文件数据，这很好。然而，我还没有完全弄清楚如何实现HTML4的回退

我的方法完全基于jQuery。对我来说，问题是它必须是一个POST-HTTP调用。我希望它是由jQuery单独完成。

解决方案:

$.ajax({
    type: "POST",
    url: "/some/webpage",
    headers: {'X-CSRF-TOKEN': csrfToken},
    data: additionalDataToSend,
    dataType: "text",
    success: function(result) {
        let blob = new Blob([result], { type: "application/octetstream" }); 

        let a = document.createElement('a');
        a.href = window.URL.createObjectURL(blob);
        a.download = "test.xml";;
        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
        window.URL.revokeObjectURL(a.href);
                        
        ...
    },
    error: errorDialog
});

解释:

我和很多人所做的是在网页上创建一个链接，指出应该下载目标，并将http-request的结果作为目标。之后，我将链接附加到文档，而不是简单地单击链接，然后删除链接。你不再需要iframe了。

神奇之处在于线条

let blob = new Blob([result], { type: "application/octetstream" }); 
a.href = window.URL.createObjectURL(blob);

The interesting point is that this solution is only working with a "blob". As you can see in other answers, some are simply using a blob but not explaining why and how to create it. As you can read e.g. in the Mozilla developer documentation you need a file, media ressource or blob for the function "createObjectURL()" to work. The problem is that your http-response might not be any of those. Therefore the first thing you must do is to convert your response to a blob. This is what the first line does. Then you can use the "createObjectURL" with your newly created blob. If you than click the link your browser will open a file-save dialog and you can save your data. Obviously it s possible that you cannot define a fixed filename for your file to download. Then you must make your response more complex like in the answer from Luke.

不要忘记释放内存，特别是在处理大文件时。要获得更多的示例和信息，您可以查看JS blob对象的详细信息