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");

10. if (string.IsNullOrEmpty(storageKey))

11. thrownew ArgumentNullException("StorageKey");

13. if (string.IsNullOrEmpty(containerName))

14. thrownew ArgumentNullException("ContainerName");

16. this.StorageAccount = storageAccount;

17. this.StorageKey = storageKey;

18. this.ContainerName = containerName;

19. }

21. public string StorageAccount { get; }

22. public string StorageKey { get; }

23. public string ContainerName { get; }

24. }

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. }

8. public IListBlobItem Item { get; }

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

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

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

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

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

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

17. "";

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

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

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

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

24. }

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);

7. //Client

8. CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

10. //Container

11. CloudBlobContainer blobContainer =

12. blobClient.GetContainerReference(settings.ContainerName);

13. await blobContainer.CreateIfNotExistsAsync();

15. return blobContainer;

16. }

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

19. {

20. //Container

21. CloudBlobContainer blobContainer = await GetContainerAsync();

23. //Blob

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

26. return blockBlob;

27. }

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

30. bool useFlatListing = true)

31. {

32. //Container

33. CloudBlobContainer blobContainer = await GetContainerAsync();

35. //List

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

37. BlobContinuationToken token = null;

38. do

39. {

40. BlobResultSegment resultSegment =

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

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

43. token = resultSegment.ContinuationToken;

45. foreach (IListBlobItem item in resultSegment.Results)

46. {

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

48. }

49. } while (token != null);

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

52. }

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);

6. //Upload

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

8. {

9. fileStream.Position = 0;

10. await blockBlob.UploadFromStreamAsync(fileStream);

11. }

12. }

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

15. {

16. //Blob

17. CloudBlockBlob blockBlob = await GetBlockBlobAsync(blobName);

19. //Upload

20. stream.Position = 0;

21. await blockBlob.UploadFromStreamAsync(stream);

22. }

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

25. {

26. //Blob

27. CloudBlockBlob blockBlob = await GetBlockBlobAsync(blobName);

29. //Download

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

31. {

32. await blockBlob.DownloadToStreamAsync(stream);

33. return stream;

34. }

35. }

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

38. {

39. //Blob

40. CloudBlockBlob blockBlob = await GetBlockBlobAsync(blobName);

42. //Download

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

44. }

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. }

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

7. {

8. var list = await GetBlobListAsync();

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

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

11. .Distinct()

12. .OrderBy(i => i)

13. .ToList();

14. }

注入和使用存储助手，

1. publicclass HomeController : Controller

2. {

3. private readonly IAzureBlobStorage blobStorage;

5. public HomeController(IAzureBlobStorage blobStorage)

6. {

7. this.blobStorage = blobStorage;

8. }

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. });

12. services.AddMvc();

13. }

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