Typescript Promise文件上传

function uploadFile(file: File): Promise<string> {
  return new Promise((resolve, reject) => {
    const formData = new FormData();
    formData.append('file', file);

    const xhr = new XMLHttpRequest();
    xhr.open('POST', '/upload', true);

    xhr.onload = () => {
      if (xhr.status === 200) {
        resolve(xhr.responseText);
      } else {
        reject(new Error('File upload failed'));
      }
    };

    xhr.onerror = () => {
      reject(new Error('File upload failed'));
    };

    xhr.send(formData);
  });
}

// 调用示例
const fileInput = document.getElementById('fileInput') as HTMLInputElement;
const file = fileInput.files[0];
uploadFile(file)
  .then((response) => {
    console.log('File upload successful:', response);
  })
  .catch((error) => {
    console.error('File upload failed:', error);
  });