js上传图片样式

<input type="file" id="imageUpload" accept="image/*">
<div id="preview"></div>

#imageUpload {
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 5px;
}

#preview {
  margin-top: 20px;
  width: 200px;
  height: 200px;
  border: 1px solid #ccc;
  display: none;
}

document.getElementById('imageUpload').addEventListener('change', function(event) {
  const file = event.target.files[0];
  if (file) {
    const reader = new FileReader();
    reader.onload = function(e) {
      const img = document.createElement('img');
      img.src = e.target.result;
      img.style.width = '100%';
      img.style.height = '100%';
      document.getElementById('preview').innerHTML = '';
      document.getElementById('preview').appendChild(img);
      document.getElementById('preview').style.display = 'block';
    };
    reader.readAsDataURL(file);
  }
});