Question

我正在尝试使用XMLHttpRequest和file.slice将一些大文件上传到服务器我已经在文档和其他各种链接的帮助下做到了这一点。
由于上传大文件是一项很长的工作，我想为用户提供一个进度条经过一些更多的阅读后，我遇到了一个example，从理论上讲，它完全符合我的需要。
通过获取示例代码并根据我的需要进行调整，我到达了

var upload =
{
blobs: [],
pageName: '',
bytesPerChunk: 20 * 1024 * 1024,
currentChunk: 0,
loaded: 0,
total: 0,
file: null,
fileName: "",

uploadChunk: function (blob, fileName, fileType) {
    var xhr = new XMLHttpRequest();

    xhr.onreadystatechange = function () {
        if (xhr.readyState == 4) {
            if (xhr.responseText) {
                // alert(xhr.responseText);
            }
        }
    };

    xhr.addEventListener("load", function (evt) {
        $("#dvProgressPrcent").html("100%");
        $get('dvProgress').style.width = '100%';
    }, false);

    xhr.addEventListener("progress", function (evt) {
        if (evt.lengthComputable) {
            var progress = Math.ceil(((upload.loaded + evt.loaded) / upload.total) * 100);
            $("#dvProgressPrcent").html(progress + "%");
            $get('dvProgress').style.width = progress + '%';
        }
    }, false);

    xhr.upload.addEventListener("progress", function (evt) {
        if (evt.lengthComputable) {
            var progress = Math.ceil(((upload.loaded + evt.loaded) / upload.total) * 100);
            $("#dvProgressPrcent").html(progress + "%");
            $get('dvProgress').style.width = progress + '%';
        }
    }, false);

    xhr.open('POST', upload.pageName, false);

    xhr.setRequestHeader("Content-Type", "multipart/form-data");
    xhr.setRequestHeader("X-File-Name", fileName);
    xhr.setRequestHeader("X-File-Type", fileType);
    xhr.send(blob);
},
upload: function (file) {
    var start = 0;
    var end = 0;
    var size = file.size;

    var date = new Date();
    upload.fileName = date.format("dd.MM.yyyy_HH.mm.ss") + "_" + file.name;

    upload.loaded = 0;
    upload.total = file.size;

    while (start < size) {
        end = start + upload.bytesPerChunk;
        if (end > size) {
            end = size;
        }

        var blob = file.slice(start, end);
        upload.uploadChunk(blob, upload.fileName, file.type);
        start = end;
        upload.loaded += start;
    }

    return upload.fileName;
}
};

呼叫就像（没有验证）

upload.upload(document.getElementById("#upload").files[0]);

我的问题是进度事件没有触发。
我已经尝试了xhr.addEventListener和xhr.upload.addEventListener（每次一次，每次都是），但是它从不会触发。 onreadystatechange和load事件触发就好了。

我非常感谢帮助我做错了什么

更新的
经过多次尝试，我设法模拟进度，但我遇到了另一个问题：Chrome的UI在上传过程中没有更新。
代码现在看起来像这样

var upload =
{
    pageName: '',
    bytesPerChunk: 20 * 1024 * 1024,
    loaded: 0,
    total: 0,
    file: null,
    fileName: "",

    uploadFile: function () {
        var size = upload.file.size;

        if (upload.loaded > size) return;

        var end = upload.loaded + upload.bytesPerChunk;
        if (end > size) { end = size; }

        var blob = upload.file.slice(upload.loaded, end);

        var xhr = new XMLHttpRequest();

        xhr.open('POST', upload.pageName, false);

        xhr.setRequestHeader("Content-Type", "multipart/form-data");
        xhr.setRequestHeader("X-File-Name", upload.fileName);
        xhr.setRequestHeader("X-File-Type", upload.file.type);

        xhr.send(blob);

        upload.loaded += upload.bytesPerChunk;

        setTimeout(upload.updateProgress, 100);
        setTimeout(upload.uploadFile, 100);
    },
    upload: function (file) {
        upload.file = file;

        var date = new Date();
        upload.fileName = date.format("dd.MM.yyyy_HH.mm.ss") + "_" + file.name;

        upload.loaded = 0;
        upload.total = file.size;

        setTimeout(upload.uploadFile, 100);


        return upload.fileName;
    },
    updateProgress: function () {
        var progress = Math.ceil(((upload.loaded) / upload.total) * 100);
        if (progress > 100) progress = 100;

        $("#dvProgressPrcent").html(progress + "%");
        $get('dvProgress').style.width = progress + '%';
    }
};

更新2
我已经设法修复它并模拟了一个在chrome中工作的进度条我已经使用有效的代码更新了以前的代码示例您可以通过减少一次上传的块的大小来更频繁地“更新”栏 Tahnk你的帮助

Answer 1

如https://stackoverflow.com/a/3694435/460368所述，你可以这样做：

if(xhr.upload)
     xhr.upload.onprogress=upload.updateProgress;

和

updateProgress: function updateProgress(evt) 
{
   if (evt.lengthComputable) {
       var progress = Math.ceil(((upload.loaded + evt.loaded) / upload.total) * 100);
       $("#dvProgressPrcent").html(progress + "%");
       $get('dvProgress').style.width = progress + '%';
   }
}

Answer 2

有我的解决方案：

function addImages(id)
{


var files= $("#files").prop("files");
var file = files[loopGallery];
var cList= files.length;

var fd = new FormData();

fd.append("file", file);
fd.append("galerie", id);


var xhr = new XMLHttpRequest();

xhr.open("POST", "moduls/galerie/uploadimages.php", true);

xhr.upload.onprogress = function(e)
{

var percentComplete = Math.ceil((e.loaded / e.total) * 100);

$("#progress").css("display","");

$("#progressText").text((loopGallery+1)+" z "+cList);
$("#progressBar").css("width",percentComplete+"%");

};


xhr.onload = function()
{

if(this.status == 200)
{
    $("#progressObsah").load("moduls/galerie/showimages.php?ids="+id);

    if((loopGallery+1) == cList)
    {
        loopGallery = 0;

    }
    else
    {
    $("#progressBar").css("width", "0%");   
loopGallery++;
addImages(id);
}

};

};

if(cList < 1)
{

}
else
{
xhr.send(fd);
}


}

使用XMLHttpRequest上传大文件时的进度条

2 个答案: