上传多个文件时，我们可以跟踪单个文件的上传进度吗？

基本上，当我处理时<input type="file" multiple/>，我总是将文件存储在另一个数组中以进行进一步的工作，例如删除特定文件。

var UploadFiles = [];

$('#input').on('change',function(){
    var files = this.files; // get files from input
    UploadFiles = files.slice(0) // storage files in UploadFiles array
})

然后，通过AJAX分别上传文件

// initialize your progress bar
$.each(UploadFiles,function(){
    let uploadFile = new FormData()
    uploadFile.append('file', this)

    $.ajax({
        // some parameters...
        , beforeSend: function(){
              // some code...
              // setting progress bar percentage as you want
          }
        , success: function(){
              // some code...
              // setting progress bar percentage as you want
          }
    }).done(function(){
        // some code...
        // setting progress bar percentage as you want
    })
})
// setting progress bar to 100%