拖到浏览器并检测正在被拖放的文件的mime

<div id="dropzone">将文件拖放到此处</div>

var dropzone = document.getElementById('dropzone');

dropzone.addEventListener('dragover', handleDragOver, false);
dropzone.addEventListener('drop', handleFileSelect, false);

function handleDragOver(event) {
  event.stopPropagation();
  event.preventDefault();
  event.dataTransfer.dropEffect = 'copy';
}

function handleFileSelect(event) {
  event.stopPropagation();
  event.preventDefault();

  var files = event.dataTransfer.files;
  // 处理文件列表
}

function handleFileSelect(event) {
  // ...

  for (var i = 0; i < files.length; i++) {
    var file = files[i];
    var fileType = file.type;
    // 处理文件的 MIME 类型
  }
}