从ajax和ActionResult下载文件

Question

我想使用ajax和ActionResult在浏览器上下载文件。该文件已下载并从我的ActionResult返回。

我看到Http查询正常，并且在响应正文中看到了数据。问题是不建议将该文件保存在浏览器中。

一切似乎都很好。我在教程和论坛中看到的所有内容都和我一样，但我没有说过XD。我不明白我和其他人之间有什么区别。

这是我的ActionResult：

public ActionResult ShippingDownloadDNPriority(string SALE_GUID)
{
    int supId = -1;
    int.TryParse(Session["SupId"].ToString(), out supId);
    if (supId < 0)
        return null;

    WebResponse response = CallApi.DownloadAndCreateDN(Session["UserLogin"].ToString(), Session["IdentConnect"].ToString(), SALE_GUID, supId, true);
    Stream responseStream = response.GetResponseStream();

    var cd = new System.Net.Mime.ContentDisposition
    {
        FileName = "myfile.pdf",
        Inline = false,
    };
    Response.Headers.Add("Content-Disposition", cd.ToString());
    Response.ContentType = "application/octet-stream";
    return File(responseStream, System.Net.Mime.MediaTypeNames.Application.Pdf, "myfile.pdf");
}

public static WebResponse DownloadAndCreateDN(string login, string session, string SALE_GUID, int supid, bool priority)
{
    string[] res = new string[2];

    StringBuilder postData = new StringBuilder();
    postData.AppendLine("{");
    postData.AppendLine(string.Format("\"login\":\"{0}\",", login));
    postData.AppendLine(string.Format("\"session\":\"{0}\",", session));
    postData.AppendLine(string.Format("\"saleguid\":\"{0}\",", SALE_GUID));
    postData.AppendLine(string.Format("\"supid\":{0},", supid));
    postData.AppendLine(string.Format("\"prority\":{0}", priority.ToString().ToLower()));
    postData.AppendLine("}");

    ASCIIEncoding ascii = new ASCIIEncoding();
    byte[] postBytes = ascii.GetBytes(postData.ToString());

    string url = Properties.Settings.Default.ISAPIAddress + "deliverynote/create";

    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
    request.Method = "POST";
    request.ContentType = "application/json";
    request.ContentLength = postBytes.Length;

    Stream postStream = request.GetRequestStream();
    postStream.Write(postBytes, 0, postBytes.Length);
    postStream.Flush();
    postStream.Close();

    return request.GetResponse();
}

这是我的javascript：

$.ajax({
    url: '../Shipping/ShippingDownloadDNPriority?SALE_GUID=XXXXXXXXXXXXXX',
    data: { SALE_GUID: DropShipping.GetRowKey(rowIndexSale) },
    async: false,
    //success: function (data) { window.downloadFile = data; }
});

谢谢大家

Answer 1

AJAX只是一个瘦客户端。默认返回的响应没有任何反应。您有责任进行下载。但是，这样做需要HTML5包含的File API。因此，这仅在现代浏览器（IE10 +）中可行。

在您的AJAX成功方法中：

var blob = new Blob(data, { type: 'application/pdf' });
var a = document.createElement('a');
var url = window.URL.createObjectURL(blob);
a.href = url;
a.download = 'myfile.pdf';
a.click();
window.URL.revokeObjectURL(url);

编辑

jQuery默认情况下无法正确解释响应类型。您需要稍微修改$ .ajax调用：

$.ajax({
    url: '../Shipping/ShippingDownloadDNPriority?SALE_GUID=XXXXXXXXXXXXXX',
    data: { SALE_GUID: DropShipping.GetRowKey(rowIndexSale) },
    async: false,
    // -- ADD THIS --
    xhrFields: {
        responseType: 'blob'
    },
    success: function (data) {
        // code above here, but no longer need to create blob
        var a = document.createElement('a');
        var url = window.URL.createObjectURL(data);
        a.href = url;
        a.download = 'myfile.pdf';
        a.click();
        window.URL.revokeObjectURL(url);
    }
});

您可以在此处签出CodePen来查看它的工作原理。

Answer 2

我改变主意了。我只需以 64 位格式发送我的 pdf（从我的控制器）并在 ajax 中制作：

success: function (data) {
     window.open("data:application/pdf;base64," + data.data, '_blank'); 
}