我是通过这种方式解决的:
1)首先给cancel事件加一个自己的函数:DeleteCancelFile
'onUploadSuccess': function (file, data, response) {
eval("data=" + data);
var cancel = $("#" + file.id + " .cancel a");
if (cancel) {
cancel.on('click', function () {
DeleteCancelFile(file.name);
});
}
}
2)在删除服务器文件后,加上下面2句就可以了,就是每次从服务器删除一个文件,就把uploadLimit + 1:
var swfuploadify = window['uploadify_file_upload'];
$("#file_upload").uploadify('settings', 'uploadLimit', swfuploadify.settings.uploadLimit + 1);