jQuery Ajax传递数组到asp.net web api参数为空

　　　　　　　　　var files = [];
files.push({ FileName: "1.jgp", Extension: ".jgp", FileType: 2 });
files.push({ FileName: "2.png", Extension: ".png", FileType: 2 });
files.push({ FileName: "3.bpm", Extension: ".bpm", FileType: 2 });

$.ajax({
url: "/api/file/uploadservice",
type: "post",
dataType: "json",
data: { "": files },
success: function (res) {
alert(res);
},
error: function (xhr ,err) {
alert(err);
}
});

/// <summary>
/// 批量上传文件
/// </summary>
/// <param name="files"></param>
/// <returns></returns>
[HttpPost]
[Route("uploadservice")]
public HttpResponseMessage AppendFiles(List<FileInfo> files)
{
//上传文件处理
}

.ajax({
url: "/api/file/uploadservice",
type: "post",
dataType: "json",
data: { "": files },
success: function (res) {
alert(res);
},
error: function (xhr ,err) {
alert(err);
}
});