我想用jQuery异步上传文件。

$(文档).ready(函数(){$(“#uploadbutton”).click(函数(){var filename=$(“#file”).val();$.ajax美元({类型:“POST”,url:“addFile.do”,enctype:'多部分/表单数据',数据:{文件:文件名},成功:函数(){alert(“上传的数据:”);}});});});<script src=“https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.0/jquery.min.js“></script><span>文件</span><input type=“file”id=“file”name=“file”size=“10”/><input id=“uploadbutton”type=“button”value=“Upload”/>

我只得到文件名,而不是上传文件。我可以做什么来解决这个问题?


当前回答

这是一个老问题,但仍然没有正确答案,因此:

您尝试过jQuery文件上载吗?

下面是上面链接中的一个示例,可以解决您的问题:

$('#fileupload').fileupload({
    add: function (e, data) {
        var that = this;
        $.getJSON('/example/url', function (result) {
            data.formData = result; // e.g. {id: 123}
            $.blueimp.fileupload.prototype
                .options.add.call(that, e, data);
        });
    } 
});

其他回答

您可以使用JavaScript或jQuery进行异步多文件上传,而无需使用任何插件。您还可以在进度控件中显示文件上载的实时进度。我遇到了两个不错的链接-

带有进度条的基于ASP.NET Web表单的多文件上载功能jQuery中基于ASP.NET MVC的多文件上载

服务器端语言是C#,但您可以进行一些修改,使其与其他语言(如PHP)一起使用。

文件上载ASP.NET核心MVC:

在html中的View create file upload控件中:

<form method="post" asp-action="Add" enctype="multipart/form-data">
    <input type="file" multiple name="mediaUpload" />
    <button type="submit">Submit</button>
</form>

现在在控制器中创建动作方法:

[HttpPost]
public async Task<IActionResult> Add(IFormFile[] mediaUpload)
{
    //looping through all the files
    foreach (IFormFile file in mediaUpload)
    {
        //saving the files
        string path = Path.Combine(hostingEnvironment.WebRootPath, "some-folder-path"); 
        using (var stream = new FileStream(path, FileMode.Create))
        {
            await file.CopyToAsync(stream);
        }
    }
}

hostingEnvironment变量的类型为IHostingEnvironment,可以使用依赖注入将其注入控制器,例如:

private IHostingEnvironment hostingEnvironment;
public MediaController(IHostingEnvironment environment)
{
    hostingEnvironment = environment;
}

示例:如果使用jQuery,您可以轻松地上传文件。这是一个小而强大的jQuery插件,http://jquery.malsup.com/form/.

实例

var $bar   = $('.ProgressBar');
$('.Form').ajaxForm({
  dataType: 'json',

  beforeSend: function(xhr) {
    var percentVal = '0%';
    $bar.width(percentVal);
  },

  uploadProgress: function(event, position, total, percentComplete) {
    var percentVal = percentComplete + '%';
    $bar.width(percentVal)
  },

  success: function(response) {
    // Response
  }
});

我希望这会有帮助

这里只是另一个如何上传文件的解决方案(没有任何插件)

使用简单的Javascript和AJAX(带有进度条)

HTML部分

<form id="upload_form" enctype="multipart/form-data" method="post">
    <input type="file" name="file1" id="file1"><br>
    <input type="button" value="Upload File" onclick="uploadFile()">
    <progress id="progressBar" value="0" max="100" style="width:300px;"></progress>
    <h3 id="status"></h3>
    <p id="loaded_n_total"></p>
</form>

JS部分

function _(el){
    return document.getElementById(el);
}
function uploadFile(){
    var file = _("file1").files[0];
    // alert(file.name+" | "+file.size+" | "+file.type);
    var formdata = new FormData();
    formdata.append("file1", file);
    var ajax = new XMLHttpRequest();
    ajax.upload.addEventListener("progress", progressHandler, false);
    ajax.addEventListener("load", completeHandler, false);
    ajax.addEventListener("error", errorHandler, false);
    ajax.addEventListener("abort", abortHandler, false);
    ajax.open("POST", "file_upload_parser.php");
    ajax.send(formdata);
}
function progressHandler(event){
    _("loaded_n_total").innerHTML = "Uploaded "+event.loaded+" bytes of "+event.total;
    var percent = (event.loaded / event.total) * 100;
    _("progressBar").value = Math.round(percent);
    _("status").innerHTML = Math.round(percent)+"% uploaded... please wait";
}
function completeHandler(event){
    _("status").innerHTML = event.target.responseText;
    _("progressBar").value = 0;
}
function errorHandler(event){
    _("status").innerHTML = "Upload Failed";
}
function abortHandler(event){
    _("status").innerHTML = "Upload Aborted";
}

PHP部分

<?php
$fileName = $_FILES["file1"]["name"]; // The file name
$fileTmpLoc = $_FILES["file1"]["tmp_name"]; // File in the PHP tmp folder
$fileType = $_FILES["file1"]["type"]; // The type of file it is
$fileSize = $_FILES["file1"]["size"]; // File size in bytes
$fileErrorMsg = $_FILES["file1"]["error"]; // 0 for false... and 1 for true
if (!$fileTmpLoc) { // if file not chosen
    echo "ERROR: Please browse for a file before clicking the upload button.";
    exit();
}
if(move_uploaded_file($fileTmpLoc, "test_uploads/$fileName")){ // assuming the directory name 'test_uploads'
    echo "$fileName upload is complete";
} else {
    echo "move_uploaded_file function failed";
}
?>

下面是示例应用程序

没有Jquery的现代方法是,当用户选择一个文件时,使用从<input type=“file”>返回的FileList对象,然后使用Fetch发布包裹在FormData对象周围的FileList。

// The input DOM element // <input type="file">
const inputElement = document.querySelector('input[type=file]');

// Listen for a file submit from user
inputElement.addEventListener('change', () => {
    const data = new FormData();
    data.append('file', inputElement.files[0]);
    data.append('imageName', 'flower');

    // You can then post it to your server.
    // Fetch can accept an object of type FormData on its  body
    fetch('/uploadImage', {
        method: 'POST',
        body: data
    });
});

你可以很容易地用普通JavaScript实现。以下是我当前项目的片段:

var xhr = new XMLHttpRequest();
xhr.upload.onprogress = function(e) {
    var percent = (e.position/ e.totalSize);
    // Render a pretty progress bar
};
xhr.onreadystatechange = function(e) {
    if(this.readyState === 4) {
        // Handle file upload complete
    }
};
xhr.open('POST', '/upload', true);
xhr.setRequestHeader('X-FileName',file.name); // Pass the filename along
xhr.send(file);