我认为最好的方法是结合使用。您的第二种方法似乎是一个优雅的解决方案，其中涉及到浏览器。

这取决于调用的方式。(无论是浏览器还是web服务调用)您可以使用两者的组合，将URL发送到浏览器并将原始数据发送到任何其他web服务客户端。

我喜欢弗兰克的想法，并决定做出自己的改变。因为尝试在一篇文章中做到这一点是非常复杂的，我使用了两篇文章的方法，但只击中数据库一次，不需要保存文件或完成后清理文件。

首先，我运行ajax请求来检索数据，但不是从控制器返回数据，而是返回一个绑定到记录的TempData存储的GUID。

$.get("RetrieveData", { name: "myParam"} , function(results){
    window.location = "downloadFile?id=" + results
});

public string RetrieveData(string name)
{
    var data = repository.GetData(name);
    string id = Guid.NewGuid().ToString();
    var file = new KeyValuePair<string, MyDataModel>(name, data);
    TempData[id]=file;
    return id;
}

然后当我呼叫窗口的时候。我将Guid传递给新方法，并从TempData获取数据。执行此方法后，TempData将是空闲的。

public ActionResult DownloadFile(string id)
{
   var file = (KeyValuePair<string,MyDataModel>)TempData[id];
   var filename = file.Key;
   var data = file.Value;
   var byteArray = Encoding.UTF8.GetBytes(data);
   ...
   return File(byteArray, "text/csv", "myFile.csv");
}

有一种更简单的方法，创建一个表单并发布它，如果返回的mime类型是浏览器会打开的，则会有重置页面的风险，但对于csv等来说，这是完美的

示例需要下划线和jquery

var postData = {
    filename:filename,
    filecontent:filecontent
};
var fakeFormHtmlFragment = "<form style='display: none;' method='POST' action='"+SAVEAS_PHP_MODE_URL+"'>";
_.each(postData, function(postValue, postKey){
    var escapedKey = postKey.replace("\\", "\\\\").replace("'", "\'");
    var escapedValue = postValue.replace("\\", "\\\\").replace("'", "\'");
    fakeFormHtmlFragment += "<input type='hidden' name='"+escapedKey+"' value='"+escapedValue+"'>";
});
fakeFormHtmlFragment += "</form>";
$fakeFormDom = $(fakeFormHtmlFragment);
$("body").append($fakeFormDom);
$fakeFormDom.submit();

对于html、text等，确保mimetype是application/octet-stream之类的东西

php代码

<?php
/**
 * get HTTP POST variable which is a string ?foo=bar
 * @param string $param
 * @param bool $required
 * @return string
 */
function getHTTPPostString ($param, $required = false) {
    if(!isset($_POST[$param])) {
        if($required) {
            echo "required POST param '$param' missing";
            exit 1;
        } else {
            return "";
        }
    }
    return trim($_POST[$param]);
}

$filename = getHTTPPostString("filename", true);
$filecontent = getHTTPPostString("filecontent", true);

header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=\"$filename\"");
echo $filecontent;

Another approach instead of saving the file on the server and retrieving it, is to use .NET 4.0+ ObjectCache with a short expiration until the second Action (at which time it can be definitively dumped). The reason that I want to use JQuery Ajax to do the call, is that it is asynchronous. Building my dynamic PDF file takes quite a bit of time, and I display a busy spinner dialog during that time (it also allows other work to be done). The approach of using the data returned in the "success:" to create a Blob does not work reliably. It depends on the content of the PDF file. It is easily corrupted by data in the response, if it is not completely textual which is all that Ajax can handle.

很久以前在某个地方找到它，它工作得很完美!

let payload = {
  key: "val",
  key2: "val2"
};

let url = "path/to/api.php";
let form = $('<form>', {'method': 'POST', 'action': url}).hide();
$.each(payload, (k, v) => form.append($('<input>', {'type': 'hidden', 'name': k, 'value': v})) );
$('body').append(form);
form.submit();
form.remove();

这个问题被问到已经有一段时间了，但我也有同样的挑战，想要分享我的解决方案。它使用了其他答案中的元素，但我无法找到它的全部。它不使用表单或iframe，但它需要post/get请求对。它不是在请求之间保存文件，而是保存post数据。这似乎既简单又有效。

客户端

var apples = new Array(); 
// construct data - replace with your own
$.ajax({
   type: "POST",
   url: '/Home/Download',
   data: JSON.stringify(apples),
   contentType: "application/json",
   dataType: "text",

   success: function (data) {
      var url = '/Home/Download?id=' + data;
      window.location = url;
   });
});

服务器

[HttpPost]
// called first
public ActionResult Download(Apple[] apples)
{
   string json = new JavaScriptSerializer().Serialize(apples);
   string id = Guid.NewGuid().ToString();
   string path = Server.MapPath(string.Format("~/temp/{0}.json", id));
   System.IO.File.WriteAllText(path, json);

   return Content(id);
}

// called next
public ActionResult Download(string id)
{
   string path = Server.MapPath(string.Format("~/temp/{0}.json", id));
   string json = System.IO.File.ReadAllText(path);
   System.IO.File.Delete(path);
   Apple[] apples = new JavaScriptSerializer().Deserialize<Apple[]>(json);

   // work with apples to build your file in memory
   byte[] file = createPdf(apples); 

   Response.AddHeader("Content-Disposition", "attachment; filename=juicy.pdf");
   return File(file, "application/pdf");
}