成功将图像上传到 Firebase 存储后，Firebase 获取下载 URL

Question

我正在尝试将单个图像上传到 Firebase 存储，然后获取其下载 url 并将其分配给一个变量。

我可以成功地将我的图片上传到 Firebase，但是我无法检索下载网址。这是我已经尝试过的。

upload() {
    let storageRef = firebase.storage().ref();
    let success = false;

    for (let selectedFile of [(<HTMLInputElement>document.getElementById('file')).files[0]]) {
      let router = this.router;
      let af = this.af;
      let folder = this.folder;
      let path = `/${this.folder}/${selectedFile.name}`;
      var iRef = storageRef.child(path);
      iRef.put(selectedFile).then((snapshot) => {
        console.log('Uploaded a blob or file! Now storing the reference at', `/${this.folder}/images/`);
        af.list(`/${folder}/images/`).push({ path: path, filename: selectedFile.name })
      });
    }

    // This part does not work
    iRef.getDownloadURL().then((url) => {this.image = url});
    console.log('IREF IS ' + iRef)
    console.log('IMAGEURL IS ' + this.image)

  }

控制台日志如下：

    IREF IS gs://my-app-159520.appspot.com/images/Screen Shot 2017-08-14 at 12.19.01.png
    view-order.component.ts:134 IMAGEURL IS undefined
Uploaded a blob or file! Now storing the reference at /images/images/

我一直在尝试使用 iRef 引用来获取下载 url，但我不断收到错误消息。我正在尝试获取 url，以便将其分配给 this.image 变量，然后使用另一个函数将其存储在我的数据库中。

Answer 1

API 已更改。使用以下获取downloadURL

  snapshot.ref.getDownloadURL().then(function(downloadURL) {
    console.log("File available at", downloadURL);
  });

Answer 2

我想我已经想通了，而且它似乎正在工作，我意识到我必须从快照中获取 downloadURL 并将其分配给 this.image，如下所示：

upload() {
    let storageRef = firebase.storage().ref();
    let success = false;

    for (let selectedFile of [(<HTMLInputElement>document.getElementById('file')).files[0]]) {
      let router = this.router;
      let af = this.af;
      let folder = this.folder;
      let path = `/${this.folder}/${selectedFile.name}`;
      var iRef = storageRef.child(path);
      iRef.put(selectedFile).then((snapshot) => {

        // added this part which as grabbed the download url from the pushed snapshot
        this.image = snapshot.downloadURL;

        console.log('Uploaded a blob or file! Now storing the reference at', `/${this.folder}/images/`);
        af.list(`/${folder}/images/`).push({ path: path, filename: selectedFile.name })

        console.log('DOWNLOAD URL IS ' + this.image)
      });
    }

  }

然后我运行我的其他函数将 URL 添加到数据库中，它已按预期运行！

所以我已经将图像上传到数据库，然后使用 put 函数中的快照，然后将我的变量 image:any 分配给快照下载URL，如下所示：

this.image = snapshot.downloadURL;

我希望这可以帮助别人！

Answer 3

在 2019 年，我通过以下功能访问了 firebase 中新保存文件的 url：

const uploadImage = async(uri) => {
  const response = await fetch(uri);
  const blob = await response.blob();
  // child arg specifies the name of the image in firebase
  const ref = firebase.storage().ref().child(guid());
  ref.put(blob).then(snapshot => {
    snapshot.ref.getDownloadURL().then(url => {
      console.log(' * new url', url)
    })
  })
}

Answer 4

.put()函数正在返回一个任务，可以用来跟踪上传状态。

例如，您可以像这样监听进度、错误或完成：

onUploadImage () {
  const self = this
  const file = self.selectedFile
  if (!file) {
    return
  }
  self.isUploading = true
  const storageRef = firebase.storage().ref('/images/' + file.name)
  const task = storageRef.put(file)
  task.on('state_changed',
    function progress (snapshot) {
      self.status = 'UPLOADING...'
      self.percentage = (snapshot.bytesTransferred / snapshot.totalBytes) * 100
    },
    function error () {
      self.status = 'FAILED TRY AGAIN!'
      self.isUploading = false
    },

    function complete (event) {
      self.status = 'UPLOAD COMPLETED'
      self.isUploading = false
      storageRef.getDownloadURL().then((url) => { console.log(url) })
    }
  )
}

Answer 5

从网络版本 v9（模块化）开始，您可以通过以下方式实现此目的：

import { getStorage, ref, uploadBytes, getDownloadURL } from "firebase/storage"; 

uploadImage = () => {
  const storage = getStorage()
  const reference = ref(storage, 'file_name.jpg')
  const file = e.target.files[0]

  uploadBytes(reference, file)
    .then(snapshot => {
      return getDownloadURL(snapshot.ref)
    })
    .then(downloadURL => {
      console.log('Download URL', downloadURL)
    })
}