Drag and drop image(s) from desktop to browser instead of searching via input

问题

I'll be honest, way out of my depth here so any help or guidance would be great.

I have a very basic input form that allows me to choose multiple images from local folders and display them on the page as well as display info such as file type/name/size.

I'd like to be able to drag and drop images into the page, rather than manually search for the images each time. This is where I'm stuck. I have no idea what I need to google to get my desired result. I've seen a lot around the file API that I genuinely don't really understand.

Here's what I have so far: https://jsfiddle.net/umx1vpwy/

Any help would be massively appreciated!

Code:

function readImage(file) {

     var reader = new FileReader();
     var image = new Image();

     reader.readAsDataURL(file);
     reader.onload = function(_file) {
       image.src = _file.target.result; // url.createObjectURL(file);
       image.onload = function() {
         var w = this.width,
           h = this.height,
           t = file.type, // ext only: // file.type.split('/')[1],
           n = file.name,
           s = ~~(file.size / 1024) + 'KB';
         $('#uploadPreview').append('<img src="' + this.src + '"> ' + w + 'x' + h + ' ' + s + ' ' + t + ' ' + n + '<br>');
       };
       image.onerror = function() {
         alert('Invalid file type: ' + file.type);
       };
     };

   }
   $("#choose").change(function(e) {
     if (this.disabled) return alert('File upload not supported!');
     var F = this.files;
     if (F && F[0])
       for (var i = 0; i < F.length; i++) readImage(F[i]);
   });

<input type="file" id="choose" multiple="multiple" />
<div id="uploadPreview"></div>

I'd just like to say that browser compatibility shouldn't be an issue as this will just be used as a tool in Chrome or Firefox.

回答1:

This should help:

var el = document.querySelector(YOUR SELECTOR);

function onDragEnter(e) {
    e.stopPropagation();
    e.preventDefault();
}

function onDragOver(e) {
    e.stopPropagation();
    e.preventDefault();
}

function onDragLeave(e) {
    e.stopPropagation();
    e.preventDefault();
}

function onDrop(e) {
    e.stopPropagation();
    e.preventDefault();
    setFiles(e.dataTransfer.files);
    return false;
}

el.addEventListener('dragenter', onDragEnter, false);
el.addEventListener('dragover', onDragOver, false);
el.addEventListener('dragleave', onDragLeave, false);
el.addEventListener('drop', onDrop, false);

function setFiles(files){
    //Here you have your files
}