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如何使用将Base64图像上载到firebase。网芯

base64 .net-core asp.net-core firebase c#

Sachith Wickramaarachchi · 技术社区 · 4 年前

在我的应用程序中,图像是Base64字符串,我需要将其存储在Firebase存储中。为了实现这一点,我首先将Base64解码到图像中,然后将其存储到本地服务器中。然后从服务器路径上传到FirebaseStorage。上传到Firebase后,从本地服务器删除图像。我的示例代码如下:,

string filename = "stackoverflow.jpg";
var folderPath = Path.Combine(_hostingEnv.WebRootPath, "dev");

//Creating dev foder if not exists
if (!Directory.Exists(folderPath)) {
  Directory.CreateDirectory(folderPath);
}

var path = Path.Combine(folderPath, filename);
File.WriteAllBytes(path, Convert.FromBase64String(req.Data));
var firebaseAutProvider = new FirebaseAuthProvider(new FirebaseConfig(_configuration["FirebaseConfig:ApiKey"]));
var firebaseAuthLink = await firebaseAutProvider.SignInWithEmailAndPasswordAsync(_configuration["FirebaseConfig:AuthEmail"], _configuration["FirebaseConfig:AuthPassword"]);

//  CancellationTokenSource can be used to cancel the upload midway
var cancellation = new CancellationTokenSource();

using(FileStream fileStream = new FileStream(path, FileMode.Open)) {
  var task = new FirebaseStorage(
      _configuration["FirebaseConfig:Bucket"],
      new FirebaseStorageOptions {
        AuthTokenAsyncFactory = () => Task.FromResult(firebaseAuthLink.FirebaseToken),
          ThrowOnCancel = true // when cancel the upload, exception is thrown. By default no exception is thrown
      })
    .Child("dev") //uploading to the firebase's storage dev folder
    .Child(_configuration["FirebaseConfig:ImageFolder"])
    .PutAsync(fileStream, cancellation.Token);
  //task.Progress.ProgressChanged += (s, e) => Console.WriteLine($"Progress: {e.Percentage} %");
  imageAccessLink = await task;
  fileStream.Dispose();
}

//Delete uploaded file from the local server, after uploading to the firebase
if (File.Exists(path))
  File.Delete(path);

它工作正常,但我担心的是,我需要在不使用本地服务器的情况下执行此操作,这意味着,我需要直接将Base64上传到firebase,而不将其保存到本地服务器。我该怎么做?我找了找 Upload a base64 image with Firebase Storage .但问题是通过网络来实现这一点。网提前谢谢。

0 回复 | 直到 4 年前

J.Salas 4 年前

您只需要使用Base64String来创建要发送到Firebase的流(通常它只需要是一个流,而不是一个文件流),比如:

byte[] bytes = Convert.FromBase64String(imageInbase64);

using(MemoryStream fileStream = new MemoryStream(bytes)) {
  var task = new FirebaseStorage(
      _configuration["FirebaseConfig:Bucket"], 
      //Continue your code ....

如果它真的需要是一个文件流,请在发送之前在内部复制该流

 tmpStream.WriteTo(fileStream);

或

 tmpStream.Position = 0;
 tmpStream.CopyTo(fileStream);

markovic-m 4 年前

您可以从同一字节数组创建MemoryStream,而不是将字节数组写入路径并创建要写入firebase的FileStream( Convert.FromBase64String(req.Data) )就像这样:

MemoryStream stream = new MemoryStream(Convert.FromBase64String(req.Data));

然后将该流而不是文件流传递给PutAsync

.PutAsync(stream, cancellation.Token);