js监听拖入文件

const fileinput = document.querySelector("#fileinput")

document.addEventListener('dragover', (e) => {
  e.preventDefault()
})

document.addEventListener('drop', (e) => {
  e.preventDefault()
  const { files } = e.dataTransfer
  if (fileinput) {
    if (files.length > 1) {
      alert("只支持单个文件")
    } else {
      console.log(files[0].name);
      fileinput.files = files
    }
  } 
})

if (fileinput) {
  fileinput.addEventListener("change", e => {
    console.log(fileinput.files)
  })
}

// @run-at       document-idle