如何使用asp.net WebMethod处理FormData AJAX帖子(带有附加参数的文件)

Question

无法将FormData的jQuery AJAX帖子处理到ASP.net 4 Web服务WebMethod.

<input id="ipt_file" type="file" />
<a href='#' onclick="UploadFile();" data-role='button'>Upload</a>

---

var UploadFile = function () {
    var file_object = $('#ipt_file')[0].files[0];
    var form_data = new FormData();
    form_data.append('job_id', '123456');
    form_data.append('job_name', 'xyx');
    form_data.append('job_file', file_object);

    var xhr_upload = $.ajax({
        type: "POST",
        headers: { "Cache-Control":"no-cache", "Content-Type":"multipart/form-data" }, // also tried without these
        url: "../MyServices.asmx/Upload",
        data: form_data,
        processData: false,
        contentType: false,
        dataType: "json",
        success: function (msg) {
            if (typeof (msg) === "object") {
                var _upload = $.parseJSON(msg.d);
                alert(_upload.status + ': ' + _upload.msg);
            };
        }
    });
};

---

public class FileUploadRequest
{
    public string job_id { get; set; }
    public string job_name { get; set; }
    public HttpPostedFile job_file { get; set; }
}

---

[WebMethod]
public string Upload(FileUploadRequest x)
{
    string str_response = string.Empty;
    if (x.job_file.ContentLength > 0)
    {
        str_response = "{\"status\":1,\"msg\":\"" + x.job_id + ", " + x.job_name + ", " + x.job_file.FileName + "\"}";
    }
    else
    {
        str_response = "{\"status\":0,\"msg\":\"FAIL"\}";
    };
    return str_response;
}

---

不能正确处理FormData对象参数; 在这里我实例化了一个自定义类,但是我从服务器返回的所有内容都是500个错误(也尝试了一个通用对象x).还尝试将其作为HttpRequest对象处理,就像我在一些帖子中看到的那样,无济于事.在这种情况下不关心IE 9的不兼容性; 只想查看单个文件上传或至少一个具有由asmx WebMethod正确接收的键/值对的FormData对象.

Answer 1

我确实让它使用以下代码,以防有人想看到它:

    var upload_file = $('#ipt_file')[0].files[0];
    var upload_filename = upload_file.name;
    var upload_maxsize = 10485760;
    var upload_projectname = "test";
    var form_data = new FormData();
    form_data.append('session_id', this.sessionID());
    form_data.append('project_name', upload_projectname);
    form_data.append('file_name', upload_filename);
    form_data.append('file_size', upload_file.size);
    form_data.append('file', upload_file);
    if (upload_file.size < upload_maxsize) {
    var xhr_upload = $.ajax({
        type: "POST",
        headers: { 'Cache-Control': 'no-cache' },
        url: "../services/upload.ashx",
        data: form_data,
        processData: false,
        contentType: false,
        dataType: "json"
        }
    })
    .done(function (xhr_data) {
        ...
    })
    .fail(function (jqXHR, textStatus, errorThrown) {
        ...
    })
    .always(function () {
        ...
    });

Answer 2

.NET不允许内容类型的multipart / form-data：

JSON劫持以及ASP.NET AJAX 1.0如何避免这些攻击

ASP.NET对基于GET和POST的ASP.NET AJAX Web方法都强制执行一个内置的保护层，即无论使用什么HTTP动词，SP.NET始终要求HTTP Content-类型标头设置为值application / json。如果未发送此内容类型标头，则ASP.NET AJAX将拒绝服务器上的请求。