C# CloudBlobContainer.DeleteIfExistsAsync方法代碼示例

        /// <summary>
        /// Basic operations to work with block blobs
        /// </summary>
        /// <returns>Task<returns>
        private static async Task BasicStorageBlockBlobOperationsWithAccountSASAsync()
        {
            const string imageToUpload = "HelloWorld.png";
            string blockBlobContainerName = "demoblockblobcontainer-" + Guid.NewGuid();

            // Call GetAccountSASToken to get a sasToken based on the Storage Account Key
            string sasToken = GetAccountSASToken();
          
            // Create an AccountSAS from the SASToken
            StorageCredentials accountSAS = new StorageCredentials(sasToken);

            //Informational: Print the Account SAS Signature and Token
            Console.WriteLine();
            Console.WriteLine("Account SAS Signature: " + accountSAS.SASSignature);
            Console.WriteLine("Account SAS Token: " + accountSAS.SASToken);
            Console.WriteLine();
            
            // Create a container for organizing blobs within the storage account.
            Console.WriteLine("1. Creating Container using Account SAS");

            // Get the Container Uri  by passing the Storage Account and the container Name
            Uri ContainerUri = GetContainerSASUri(blockBlobContainerName);

            // Create a CloudBlobContainer by using the Uri and the sasToken
            CloudBlobContainer container = new CloudBlobContainer(ContainerUri, new StorageCredentials(sasToken));
            try
            {
                await container.CreateIfNotExistsAsync();
            }
            catch (StorageException)
            {
                Console.WriteLine("If you are running with the default configuration please make sure you have started the storage emulator. Press the Windows key and type Azure Storage to select and run it from the list of applications - then restart the sample.");
                Console.ReadLine();
                throw;
            }

            // To view the uploaded blob in a browser, you have two options. The first option is to use a Shared Access Signature (SAS) token to delegate 
            // access to the resource. See the documentation links at the top for more information on SAS. The second approach is to set permissions 
            // to allow public access to blobs in this container. Uncomment the line below to use this approach. Then you can view the image 
            // using: https://[InsertYourStorageAccountNameHere].blob.core.windows.net/democontainer/HelloWorld.png
            // await container.SetPermissionsAsync(new BlobContainerPermissions { PublicAccess = BlobContainerPublicAccessType.Blob });

            // Upload a BlockBlob to the newly created container
            Console.WriteLine("2. Uploading BlockBlob");
            CloudBlockBlob blockBlob = container.GetBlockBlobReference(imageToUpload);
            await blockBlob.UploadFromFileAsync(imageToUpload, FileMode.Open);

            // List all the blobs in the container 
            Console.WriteLine("3. List Blobs in Container");
            foreach (IListBlobItem blob in container.ListBlobs())
            {
                // Blob type will be CloudBlockBlob, CloudPageBlob or CloudBlobDirectory
                // Use blob.GetType() and cast to appropriate type to gain access to properties specific to each type
                Console.WriteLine("- {0} (type: {1})", blob.Uri, blob.GetType());
            }

            // Download a blob to your file system
            Console.WriteLine("4. Download Blob from {0}", blockBlob.Uri.AbsoluteUri);
            await blockBlob.DownloadToFileAsync(string.Format("./CopyOf{0}", imageToUpload), FileMode.Create);

            // Create a read-only snapshot of the blob
            Console.WriteLine("5. Create a read-only snapshot of the blob");
            CloudBlockBlob blockBlobSnapshot = await blockBlob.CreateSnapshotAsync(null, null, null, null);

            // Clean up after the demo 
            Console.WriteLine("6. Delete block Blob and all of its snapshots");
            await blockBlob.DeleteIfExistsAsync(DeleteSnapshotsOption.IncludeSnapshots, null, null, null);

            Console.WriteLine("7. Delete Container");
            await container.DeleteIfExistsAsync();

        }

 public async Task<bool> DeleteContainerAsync(string containerName)
 {
     // Delete the container if it doesn't exist.
     blobContainer = blobClient.GetContainerReference(containerName);
     return await blobContainer.DeleteIfExistsAsync();
 }

        /// <summary>
        /// Basic operations to work with block blobs
        /// </summary>
        /// <returns>A Task object.</returns>
        private static async Task BasicStorageBlockBlobOperationsWithAccountSASAsync()
        {
            const string ImageToUpload = "HelloWorld.png";
            string containerName = ContainerPrefix + Guid.NewGuid();

            // Get an account SAS token.
            string sasToken = GetAccountSASToken();

            // Use the account SAS token to create authentication credentials.
            StorageCredentials accountSAS = new StorageCredentials(sasToken);

            // Informational: Print the Account SAS Signature and Token.
            Console.WriteLine();
            Console.WriteLine("Account SAS Signature: " + accountSAS.SASSignature);
            Console.WriteLine("Account SAS Token: " + accountSAS.SASToken);
            Console.WriteLine();

            // Get the URI for the container.
            Uri containerUri = GetContainerUri(containerName);

            // Get a reference to a container using the URI and the SAS token.
            CloudBlobContainer container = new CloudBlobContainer(containerUri, accountSAS);

            try
            {
                // Create a container for organizing blobs within the storage account.
                Console.WriteLine("1. Creating Container using Account SAS");

                await container.CreateIfNotExistsAsync();
            }
            catch (StorageException e)
            {
                Console.WriteLine(e.ToString());
                Console.WriteLine("If you are running with the default configuration, please make sure you have started the storage emulator. Press the Windows key and type Azure Storage to select and run it from the list of applications - then restart the sample.");
                Console.ReadLine();
                throw;
            }

            try
            {
                // To view the uploaded blob in a browser, you have two options. The first option is to use a Shared Access Signature (SAS) token to delegate 
                // access to the resource. See the documentation links at the top for more information on SAS. The second approach is to set permissions 
                // to allow public access to blobs in this container. Uncomment the line below to use this approach. Then you can view the image 
                // using: https://[InsertYourStorageAccountNameHere].blob.core.windows.net/democontainer/HelloWorld.png
                // await container.SetPermissionsAsync(new BlobContainerPermissions { PublicAccess = BlobContainerPublicAccessType.Blob });

                // Upload a BlockBlob to the newly created container
                Console.WriteLine("2. Uploading BlockBlob");
                CloudBlockBlob blockBlob = container.GetBlockBlobReference(ImageToUpload);
                await blockBlob.UploadFromFileAsync(ImageToUpload);

                // List all the blobs in the container 
                Console.WriteLine("3. List Blobs in Container");
                BlobContinuationToken token = null;
                do
                {
                    BlobResultSegment resultSegment = await container.ListBlobsSegmentedAsync(token);
                    token = resultSegment.ContinuationToken;
                    foreach (IListBlobItem blob in resultSegment.Results)
                    {
                        // Blob type will be CloudBlockBlob, CloudPageBlob or CloudBlobDirectory
                        Console.WriteLine("{0} (type: {1}", blob.Uri, blob.GetType());
                    }
                }
                while (token != null);

                // Download a blob to your file system
                Console.WriteLine("4. Download Blob from {0}", blockBlob.Uri.AbsoluteUri);
                await blockBlob.DownloadToFileAsync(string.Format("./CopyOf{0}", ImageToUpload), FileMode.Create);

                // Create a read-only snapshot of the blob
                Console.WriteLine("5. Create a read-only snapshot of the blob");
                CloudBlockBlob blockBlobSnapshot = await blockBlob.CreateSnapshotAsync(null, null, null, null);

                // Delete the blob and its snapshots.
                Console.WriteLine("6. Delete block Blob and all of its snapshots");
                await blockBlob.DeleteIfExistsAsync(DeleteSnapshotsOption.IncludeSnapshots, null, null, null);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                Console.ReadLine();
                throw;
            }
            finally
            {
                // Clean up after the demo.
                // Note that it is not necessary to delete all of the blobs in the container first; they will be deleted
                // with the container. 
                Console.WriteLine("7. Delete Container");
                await container.DeleteIfExistsAsync();
            }
        }