Firebase 存儲：`put` 預期 Blob 或文件中的參數無效

Question

我正在學習教程並嘗試使用網絡攝像頭作為 jpeg 捕獲圖像，我想將其上傳到 firebase 存儲，在那里它要求我將其上傳為文件或 blob。 當我使用<input type = 'file'>格式時，我可以上傳圖像，但我想直接從網絡攝像頭捕獲上傳圖像。 無論如何將jpeg轉換為文件或blob？

這是代碼

import React, { useState } from 'react'
import Webcam from 'react-webcam'
import firebase from 'firebase'

const WebcamComponent = () => <Webcam/>

const videoConstraints = {
  width: 220,
  height: 200,
  facingMode: 'user'
}

const WebcamCapture = () => {
  const webcamRef = React.useRef(null)

  const [image, setImage] = useState('')

  const capture = React.useCallback(
    () => {
      const imageSrc = webcamRef.current.getScreenshot()

      setImage(imageSrc)

      const file = image
      var storage = firebase.storage()
      storage.ref('FormPhotos/' + file.name).put(file).on('state_changed', alert('success'), alert)
      console.log(image)
    },
    [webcamRef]
  )

  return (
    <div className = 'webcam-container'>
      <div className = 'webcam-img'>
        {
          image == '' ? <Webcam
            audio = {false}
            height = {200}
            ref = {webcamRef}
            screenshotFormat = 'image/jpeg'
            width = {220}
            videoConstraints = {videoConstraints}
          /> : <img src = {image}/>}
      </div>
      <div>
        {
          image != ''

            ? <button onClick = {(e) => {
              e.preventDefault()
              setImage('')
            }} className = 'webcam-btn'>
            Retake Image
            </button>
            : <button onClick = {(e) => {
              e.preventDefault()
              capture()
            }}>Capture</button>
        }
      </div>
    </div>
  )
}

export default WebcamCapture

Answer 1

getScreenshot()方法返回當前網絡攝像頭圖像的 base64 編碼字符串。 使用putString方法，而不是put並傳遞imageSrc在它：

const imageSrc = webcamRef.current.getScreenshot()
const base64String = imageSrc.split(',')[1]
var storage = firebase.storage()
storage
  .ref('FormPhotos/' + file.name)
  .putString(base64string, "base64", {contentType: 'image/jpeg'})
  .then(() => {
    console.log("Image uploaded")
  }).catch((e) => console.log(e))

從文檔中，

如果未指定 contentType 元數據且文件沒有文件擴展名，則 Cloud Storage 默認為類型 application/octet-stream。