javascript - 如何将文件附加到 formData

Question

我正在以非正常方式获取文件及其值。表单中没有实际输入。因此，我尝试将文件附加到 formData 以进行 ajax 提交。

每当我尝试使用以下方法提交表单时，我的文件都不会上传。因此，我附加文件的方式一定是不正确的。

有人告诉我以下内容，但我不知道该怎么做:

You're looping through the array but appending the entire array everytime through the loop. Use the brackets on the form input name andappend each file in the array.

有人知道我需要更改什么才能使其正常工作吗？

拖放区代码...在下面的相关代码之前:

var dragFileName = '';

var myDropzone = new Dropzone("#myDropzone", {
//$('#myDropzone').dropzone ({
//Dropzone.options.myDropzone= {
    url: 'php/quoteSendTest.php',
    autoProcessQueue: false,
    paramName: "file",
    uploadMultiple: true,
    parallelUploads: 5,
    maxFiles: 5,
    maxFilesize: 25,
    acceptedFiles: 'image/*',
    addRemoveLinks: true,
    dictFileTooBig: 'File is larger than 25MB',
    init: function() {
        dzClosure = this; // Makes sure that 'this' is understood inside the functions below.

        // for Dropzone to process the queue (instead of default form behavior):
    /*  document.getElementById("submit-all").addEventListener("click", function(e) {
            // Make sure that the form isn't actually being sent.
            console.log("Something should be showing for eventListener");
            //e.preventDefault();
            e.stopPropagation();
            dzClosure.processQueue();
        });*/

        this.on("addedfile", function(file) {
            /* Maybe display some more file information on your page */
            dragFileName = file.name;
            var dragFileSize = file.size;
            var count = myDropzone.files.length;
            console.log('File added - ' + file.name + ' - Size - ' + file.size);
            console.log(count + " is the length");
            //console.log("FILEname is " + dragFileName);
            setTimeout(function () {
                toggleUploadButton();
            }, 10);
        });

        //send all the form data along with the files:
        /*this.on("sendingmultiple", function(data, xhr, formData) {
            //formData.append("firstname", jQuery("#firstname").val());
            //formData.append("lastname", jQuery("#lastname").val());
        });
        */
    }
});

相关代码:

var acceptedFiles = null;
var allAcceptFiles = null;

function toggleUploadButton() {
    acceptedFiles = myDropzone.getAcceptedFiles();
    allAcceptFiles = acceptedFiles.values();

    for (let fileElements of allAcceptFiles) {
        console.log(fileElements);
    }
}

function submit(){
    var form = document.getElementById("salesforce_submit");
    var formData = new FormData(form);
    fileElements.each(function() {
        formData.append('uploadedFile[]', fileElements);
    });
    alert(formData);

    $.ajax({
        url: '/php/quoteSendTest.php',
        type: 'POST',
        data: formData,

HTML:

<form action="<?php echo $config['sf_url']; ?>" method="POST" id="salesforce_submit">
    <input id="first_name" name="first_name" type="text">
    <div class="dropzone dz-clickable" id="myDropzone">
        <div class="dz-default dz-message dG">Drop files here or click to upload</div>
    </div>
    <button type="submit" id="submit-all">SEND PROJECT QUOTE</button>
</form>

来自 fileElements 的 Console.log 信息:

File {upload: {…}, status: "queued", previewElement:

div.dz-preview.dz-file-preview, previewTemplate:

div.dz-preview.dz-file-preview, _removeLink: a.dz-remove, …} accepted:

true dataURL: "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAABtUA"

height: 892 lastModified: 1512405192880 lastModifiedDate: Mon Dec 04

2017 11:33:12 GMT-0500 (Eastern Standard Time) {} name:

"analytics.PNG" previewElement: div.dz-preview.dz-image-preview

previewTemplate: div.dz-preview.dz-image-preview size: 544438 status:

"queued" type: "image/png" upload: {uuid:"6dc946e7-e9db-4b3a-88af-b790de1c2975", progress: 0, total: 544438,bytesSent: 0, filename: "analytics.PNG", …} webkitRelativePath: ""

width: 1749

_removeLink: a.dz-remove

proto: File

Answer 1

在您最初的尝试中:

function toggleUploadButton() {
    acceptedFiles = myDropzone.getAcceptedFiles();
    allAcceptFiles = acceptedFiles.values();

    for (let fileElements of allAcceptFiles) {
        console.log(fileElements);
    }
}

var formData = new FormData(form);
fileElements.each(function() {
    formData.append('uploadedFile[]', fileElements);
});

您正在循环遍历 allAcceptFiles 并将每个文件设置为 fileElements。这使得 fileElements 成为单个文件，当稍后尝试执行 each 循环时，它不会按照您的预期运行。

我注意到 myDropzone 必须在某个地方定义，因为它在第一个函数中工作。看着dropzone documentation ，我看到它有一个 getAcceptedFiles 方法，您可以轻松地使用该方法循环遍历并将每个文件添加到表单数据中。修改后的循环如下:

var formData = new FormData(form);
myDropzone.getAcceptedFiles().forEach(file => {
    formData.append("uploadedFile[]", file); 
});

还有一些其他内容在代码中似乎不是必需的，但这不是代码审查，因此我将不理会它们。