ASP.NET Core 2.0中的Azure Blob存储

问题

如何在ASP.NET Core中使用Azure Blob存储

解

创建一个类库并添加NuGet包 - WindowsAzure.Storage

添加一个类来封装设置，

1. publicclass AzureBlobSetings

2. {

3. public AzureBlobSetings(string storageAccount,

4. string storageKey,

5. string containerName)

6. {

7. if (string.IsNullOrEmpty(storageAccount))

8. thrownew ArgumentNullException("StorageAccount");

9. if (string.IsNullOrEmpty(storageKey))

10. thrownew ArgumentNullException("StorageKey");

11. if (string.IsNullOrEmpty(containerName))

12. thrownew ArgumentNullException("ContainerName");

13. this.StorageAccount = storageAccount;

14. this.StorageKey = storageKey;

15. this.ContainerName = containerName;

16. }

17. public string StorageAccount { get; }

18. public string StorageKey { get; }

19. public string ContainerName { get; }

20. }

添加一个类来封装一个blob项目，

1. publicclass AzureBlobItem

2. {

3. public AzureBlobItem(IListBlobItem item)

4. {

5. this.Item = item;

6. }

7. public IListBlobItem Item { get; }

8. public bool IsBlockBlob => Item.GetType() == typeof(CloudBlockBlob);

9. public bool IsPageBlob => Item.GetType() == typeof(CloudPageBlob);

10. public bool IsDirectory => Item.GetType() == typeof(CloudBlobDirectory);

11. public string BlobName => IsBlockBlob ? ((CloudBlockBlob)Item).Name :

12. IsPageBlob ? ((CloudPageBlob)Item).Name :

13. IsDirectory ? ((CloudBlobDirectory)Item).Prefix :

14. "";

15. public string Folder => BlobName.Contains("/") ?

16. BlobName.Substring(0, BlobName.LastIndexOf("/")) : "";

17. public string Name => BlobName.Contains("/") ?

18. BlobName.Substring(BlobName.LastIndexOf("/") + 1) : BlobName;

19. }

Add a class to encapsulate storage access. Add a private helper methods to access storage,

1. private async Task<CloudBlobContainer> GetContainerAsync()

2. {

3. //Account

4. CloudStorageAccount storageAccount = new CloudStorageAccount(

5. new StorageCredentials(settings.StorageAccount, settings.StorageKey), false);

6. //Client

7. CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

8. //Container

9. CloudBlobContainer blobContainer =

10. blobClient.GetContainerReference(settings.ContainerName);

11. await blobContainer.CreateIfNotExistsAsync();

12. return blobContainer;

13. }

14. private async Task<CloudBlockBlob> GetBlockBlobAsync(string blobName)

15. {

16. //Container

17. CloudBlobContainer blobContainer = await GetContainerAsync();

18. //Blob

19. CloudBlockBlob blockBlob = blobContainer.GetBlockBlobReference(blobName);

20. return blockBlob;

21. }

22. private async Task<List<AzureBlobItem>> GetBlobListAsync(

23. bool useFlatListing = true)

24. {

25. //Container

26. CloudBlobContainer blobContainer = await GetContainerAsync();

27. //List

28. var list = new List<AzureBlobItem>();

29. BlobContinuationToken token = null;

30. do

31. {

32. BlobResultSegment resultSegment =

33. await blobContainer.ListBlobsSegmentedAsync("", useFlatListing,

34. new BlobListingDetails(), null, token, null, null);

35. token = resultSegment.ContinuationToken;

36. foreach (IListBlobItem item in resultSegment.Results)

37. {

38. list.Add(new AzureBlobItem(item));

39. }

40. } while (token != null);

41. return list.OrderBy(i => i.Folder).ThenBy(i => i.Name).ToList();

42. }

现在添加公共方法来上传和下载blob项目，

1. public async Task UploadAsync(string blobName, string filePath)

2. {

3. //Blob

4. CloudBlockBlob blockBlob = await GetBlockBlobAsync(blobName);

5. //Upload

6. using (var fileStream = System.IO.File.Open(filePath, FileMode.Open))

7. {

8. fileStream.Position = 0;

9. await blockBlob.UploadFromStreamAsync(fileStream);

10. }

11. }

12. public async Task UploadAsync(string blobName, Stream stream)

13. {

14. //Blob

15. CloudBlockBlob blockBlob = await GetBlockBlobAsync(blobName);

16. //Upload

17. stream.Position = 0;

18. await blockBlob.UploadFromStreamAsync(stream);

19. }

20. public async Task<MemoryStream> DownloadAsync(string blobName)

21. {

22. //Blob

23. CloudBlockBlob blockBlob = await GetBlockBlobAsync(blobName);

24. //Download

25. using (var stream = new MemoryStream())

26. {

27. await blockBlob.DownloadToStreamAsync(stream);

28. return stream;

29. }

30. }

31. public async Task DownloadAsync(string blobName, string path)

32. {

33. //Blob

34. CloudBlockBlob blockBlob = await GetBlockBlobAsync(blobName);

35. //Download

36. await blockBlob.DownloadToFileAsync(path, FileMode.Create);

37. }

添加方法来获取blob项目列表，

1. public async Task<List<AzureBlobItem>> ListAsync()

2. {

3. return await GetBlobListAsync();

4. }

5. public async Task<List<string>> ListFoldersAsync()

6. {

7. var list = await GetBlobListAsync();

8. return list.Where(i => !string.IsNullOrEmpty(i.Folder))

9. .Select(i => i.Folder)

10. .Distinct()

11. .OrderBy(i => i)

12. .ToList();

13. }

注入和使用存储助手，

1. publicclass HomeController : Controller

2. {

3. private readonly IAzureBlobStorage blobStorage;

4. public HomeController(IAzureBlobStorage blobStorage)

5. {

6. this.blobStorage = blobStorage;

7. }

注意

示例代码具有一个控制器，其中包含列出，下载和上载项目的操作。

在 ASP.NET核心 Web应用程序中，配置服务，

1. publicvoid ConfigureServices(

2. IServiceCollection services)

3. {

4. services.AddScoped<IAzureBlobStorage>(factory =>

5. {

6. returnnew AzureBlobStorage(new AzureBlobSetings(

7. storageAccount: Configuration["Blob_StorageAccount"],

8. storageKey: Configuration["Blob_StorageKey"],

9. containerName: Configuration["Blob_ContainerName"]));

10. });

11. services.AddMvc();

12. }

讨论

示例代码将要求您设置Azure帐户，Blob存储帐户和容器。这些指令可以在这里找到