上传图片时如何显示下载网址

Question

此代码成功上传了文件，但下载后不会显示下载网址

控制台显示错误

<script src="https://www.gstatic.com/firebasejs/4.9.0/firebase.js"></script>
 <script>

   var config = {
 // Initialize Firebase
};

   firebase.initializeApp(config);
   var snapshot;

var  uploader = document.getElementById('uploader');
var fileButton = document.getElementById('fileButton');
fileButton.addEventListener('change' , function(e) {

var file= e.target.files[0];
var storageRef = firebase.storage().ref('pics/' + file.name);

var task = storageRef.put(file);   


task.on('state_changed' , 

function progress(){
    var percentage = (task.snapshot.bytesTransferred / task.snapshot.totalBytes) * 100;
    uploader.value = percentage;



},
function error(err){

},
function complete(res)
{ 
    console.log("Complete Response :" + res);

     }
);


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



 </script>

*我希望在文件上传后立即打印下载链接*

控制台显示错误

Answer 1

解决方案：

您需要在附近的代码中稍作修改。

function progress(){
    var percentage = (task.snapshot.bytesTransferred / task.snapshot.totalBytes) * 100;
    uploader.value = percentage;



},
function error(err){

},
function complete(res)
{ 
    console.log("Complete Response :" + res);

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

参考Firebase：

// File or Blob named mountains.jpg
var file = ...

// Create the file metadata
var metadata = {
  contentType: 'image/jpeg'
};

// Upload file and metadata to the object 'images/mountains.jpg'
var uploadTask = storageRef.child('images/' + file.name).put(file, metadata);

// Listen for state changes, errors, and completion of the upload.
uploadTask.on(firebase.storage.TaskEvent.STATE_CHANGED, // or 'state_changed'
  function(snapshot) {
    // Get task progress, including the number of bytes uploaded and the total number of bytes to be uploaded
    var progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
    console.log('Upload is ' + progress + '% done');
    switch (snapshot.state) {
      case firebase.storage.TaskState.PAUSED: // or 'paused'
        console.log('Upload is paused');
        break;
      case firebase.storage.TaskState.RUNNING: // or 'running'
        console.log('Upload is running');
        break;
    }
  }, function(error) {

  // A full list of error codes is available at
  // https://firebase.google.com/docs/storage/web/handle-errors
  switch (error.code) {
    case 'storage/unauthorized':
      // User doesn't have permission to access the object
      break;

    case 'storage/canceled':
      // User canceled the upload
      break;

    ...

    case 'storage/unknown':
      // Unknown error occurred, inspect error.serverResponse
      break;
  }
}, function() {
  // Upload completed successfully, now we can get the download URL
  uploadTask.snapshot.ref.getDownloadURL().then(function(downloadURL) {
    console.log('File available at', downloadURL);
  });
});