Ajax文件发布在IE8和IE9中不起作用怎么办？

如何使用Ajax发布文件？现在我使用的是formData：

    $("#image_upload").change(function() {

        var $form = $(this).closest('form');
        $form.append('<div class="loading-overlay"><div class="loading-overlay__gif"><img src="/images/preloader.gif" class="loading-overlay__gif" /></div></div>');

        $('#photo-choice-error').remove();

        var formData = new FormData();
        formData.append('image', $(this)[0].files[0]);
        // ...
    });

但是它在某些浏览器中不起作用，特别是在IE8和IE9中。如何解决呢？

I don't think IE 8/9 have support for FormData. AFAIK FormData is available from IE 10.

You could instead try using JQuery Forms, which works on IE 8 onwards.