将CaptureVisibleTab图像保存到要通过Node.js服务器发送的临时文件

// 捕获可见区域图像并发送到服务器
function captureAndSend() {
  var canvas = document.createElement('canvas');
  var context = canvas.getContext('2d');
  var width = window.innerWidth;
  var height = window.innerHeight;

  canvas.width = width;
  canvas.height = height;

  context.drawImage(document.documentElement, 0, 0, width, height);

  var imageDataURL = canvas.toDataURL('image/png');

  // 发送POST请求到服务器
  fetch('/saveImage', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({ image: imageDataURL })
  })
  .then(response => {
    console.log('Image sent successfully');
  })
  .catch(error => {
    console.error('Error sending image:', error);
  });
}

const fs = require('fs');

// 处理保存图像的请求
app.post('/saveImage', (req, res) => {
  const imageDataURL = req.body.image;
  const imageData = Buffer.from(imageDataURL.split(',')[1], 'base64');
  const filePath = '/tmp/image.png'; // 临时文件路径

  fs.writeFile(filePath, imageData, (error) => {
    if (error) {
      console.error('Error saving image:', error);
      res.status(500).send('Error saving image');
    } else {
      console.log('Image saved successfully');
      res.send('Image saved');
    }
  });
});