FormData 拖拽上传显示上传进度

upload接口地址
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>拖拽</title>
    <style>
        #drag_box{
            width:100px;
            height:100px;
            border:1px solid orange;
            background:#ccc;
            cursor: pointer;
        }
        #box{
            width:100%;
            height:400px;
            background:#eee;
            margin:10px 0px;
        }
        #box .item{
            float:left;
            margin:5px;
            position:relative;
        }
        #box .item .item-progress{
            position:absolute;
            left:50%;
            top:50%;
            width:80px;
            height:80px;
            transform: translate(-50%, -50%);
            background:rgba(0,0,0,.6);
            border-radius:40px;
            color:#fff;
            text-align: center;
            line-height:80px;
        }
        #box img{
            
            max-height: 150px;
        }
        .over{
            border:2px dashed #ccc;
            transform: scale(0.9, 0.9);
        }
    </style>
</head>
<body>
    <h3>请把文件夹中的图片拖到下面区域</h3>
    
    <div id="box">
    </div>
    <script>
        //获取目标元素
        var box = document.querySelector("#box");
        //给目标元素绑定事件
        box.addEventListener("dragenter", function(){
            this.classList.add('over');
        }, false);

        box.addEventListener("dragleave", function(){
            this.classList.remove("over");
        }, false);

        box.addEventListener("dragover", function(e){
            e.preventDefault();  //阻止默认的动作
        }, false);

        box.addEventListener("drop", function(e){
            e.preventDefault(); //阻止浏览器默认行为

            //遍历FileList
            [].forEach.call(e.dataTransfer.files, function(itemFile){

                //创建imte
                var itemEle = document.createElement("div");
                itemEle.className = "item";
                document.getElementById("box").appendChild(itemEle);

                //读取文件
                readImage(itemFile, itemEle);
                //上传文件
                uploadImage(itemFile, itemEle);

            })
            this.classList.remove("over");  //恢复样式
        },false);

        /**
         * 读取图片
         * @param File  fileObj 
         * @Param element ele  要预览插入的元素
        */
        function readImage(fileObj, ele) {
            //创建FileReader对象
            var frObj = new FileReader();

            //监听读取成功
            frObj.onload = function(){
                var img = document.createElement("img");
                img.src = frObj.result;
                ele.appendChild(img);
            }

            //读取
            frObj.readAsDataURL(fileObj);
        }


        /**
         * 上传文件
         * @param object FileObj对象
         * @param element ele对象
        */
        function uploadImage(fileObj, ele){
            //创建FormData
            var fd = new FormData();
            fd.append("uploadfile", fileObj);

            //创建元素
            var progressEle = document.createElement("div");
            progressEle.className = "item-progress";
            ele.appendChild(progressEle);

            progressEle.innerHTML = "0%";

            //XHR
            var xhr = new XMLHttpRequest();
            xhr.onload = function(){
                console.log(xhr.responseText);
                //上传进度去掉
                setTimeout(function(){
                    ele.removeChild(progressEle);
                }, 500)
            }
            //上传对象
            xhr.upload.onprogress = function(en){
                progressEle.innerHTML = (en.loaded/en.total).toFixed(2)*100 + "%";
            }
            xhr.open("POST", "upload.php");
            xhr.send(fd);
        }
    </script>
</body>
</html>
FormData 拖拽上传 显示上传进度

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FormData 拖拽上传显示上传进度
