【JS】XMLHttpRequest使用笔记

            var xhr = new XMLHttpRequest();
　　　　　　　try {
                //加载中
                Showloading();
            }
            catch (err) { }
            xhr.open(‘POST‘, url);
            xhr.setRequestHeader("Content-type", "multipart/form-data");
            xhr.responseType = ‘json‘;
            xhr.send(formData);
           
            xhr.onload = function (res) {
                console.log(‘done‘, res.target.response)
                $("#loadDIV").remove();
                var result = res.target.response
                if (cusobj) {
                    result.cusobj = cusobj
                }
                if (typeof (options.success) == ‘function‘) {
                    options.success(result);
                }
            }

            xhr.onerror = function (res) {
                alert("上传失败");
            }

            xhr.onloadend = function (res) {
                $("#loadDIV").remove();
            }

function Showloading() {
    var div1 = ‘<div  id="loadDIV" class="layerbg"><div class="waitlayer"><div class="wtimg"><img src="/images/loading1.gif" width="32" height="32" /></div>‘;
    div1 += ‘<div class="wttxt">加载中...</div></div></div>‘;
    $(document.body).append(div1);
}