input 原声上传文件 file转化为binary对象发送给后台

具体代码如下：

function filechange(e) {
                var file = $('#filed').get(0).files[0];
                var fileSize = file.size,
                    fileType = file.type;
                if (file.name.lastIndexOf('.') == -1) {
                    $.dialog({
                        content: '路径不正确',
                        time: 2000
                    });
                    return false;
                }
                var AllImgExt = ".jpg|.jpeg|.gif|.bmp|.png|.swf|";
                var extName = file.name.substring(file.name.lastIndexOf(".")).toLowerCase();
                if (AllImgExt.indexOf(extName + "|") == -1) {
                    $.dialog({
                        content: '非法图片格式',
                        time: 2000
                    });
                    return false;
                }
                if (fileSize < 3145728) {
                    if (window.FileReader) {
                        //var reader = new FileReader();
                        //reader.readAsBinaryString(file);
                        //reader.onload = function(e) {
                            var formData = new FormData();
                            formData.append("imgs", file);
                            $.ajax({
                                url: "",//后台地址
                                type: 'post',
                                //contentType: "multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW",//格式转换为binary
                                data: formData,
                                processData: false, // 使数据不做处理
                                contentType: false,
                                dataType: 'json',
                                success: function(d) {
 
                                }
                            })
                        }
                    //}
                } else {
                    $.dialog({
                        content: '图片大小超过限制',
                        time: 2000
                    });
                    return false;
                }
 
            }