AJAX实现文件上传功能报错Currentrequestisnotamultipartrequest详解

<meta Http-equiv="Content-Type" content="multipart/fORM-data; charset=utf-8" />

<form method="post" enctype="multipart/form-data">
    <input type="file" name="file" />
</form>

$('#upload-ok').click(function () {
        var form = document.getElementById("upload-form");
        var file = new FormData(form);
        $.ajax({
            url: "/addFile",
            type: "POST",
            processData:false,
            contentType:false,
            data:{
                "file":file
            },
            success: function (date) {
                xxxxxx
            },
            error: function (date) {
                xxxxxx
            }
        })
    })

$('#upload-ok').click(function () {
        var form = document.getElementById("upload-form");
        var file = new FormData(form);
        $.ajax({
            url: "/addFile",
            type: "POST",
            processData:false,
            contentType:false,
            //重要部分，data的传的是整个表单，不用大括号包裹；不用自定义变量名
            data:file,
            success: function (date) {
                xxxxxx
            },
            error: function (date) {
                xxxxxx
            }
        })
    })