CloudBlob.BeginDeleteIfExists Method (AsyncCallback, Object)
From Storage Client Library NET API
Begins an asynchronous operation to delete the blob if it exists.
Namespace: Microsoft.WindowsAzure.StorageClient
Assembly: Microsoft.WindowsAzure.StorageClient (in Microsoft.WindowsAzure.StorageClient.dll)
Usage
| Visual Basic |
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Dim instance As CloudBlob Dim callback As AsyncCallback Dim state As Object Dim returnValue As IAsyncResult returnValue = instance.BeginDeleteIfExists(callback, state) |
Syntax
| Visual Basic |
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Public Function BeginDeleteIfExists ( _ callback As AsyncCallback, _ state As Object _ ) As IAsyncResult |
| C# |
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public IAsyncResult BeginDeleteIfExists ( AsyncCallback callback, Object state ) |
| C++ |
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public: IAsyncResult^ BeginDeleteIfExists ( AsyncCallback^ callback, Object^ state ) |
| J# |
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| JScript |
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Parameters
- callback
Type: System.AsyncCallback
The callback delegate that will receive notification when the asynchronous operation completes.
- state
Type: System.Object
A user-defined object that will be passed to the callback delegate.
Return Value
Type: System.IAsyncResult
An IAsyncResult that references the asynchronous operation.
Example
The following code example deletes a blob if it exists, and it does it using an asynchronous call.
| C# | Copy Code |
|---|---|
private void Eg_BeginDeleteBlobIfExists2(Uri blobEndpoint, string accountName, string accountKey)
{
// Create a service client for credentialed access to the Blob service.
CloudBlobClient blobClient =
new CloudBlobClient(blobEndpoint,
new StorageCredentialsAccountAndKey(accountName, accountKey));
// Create a blob reference.
CloudBlob myBlob = blobClient.GetBlobReference("mycontainer/myblob.txt");
// Use the blob reference to create and initialize an actual blob instance in the cloud.
myBlob.UploadFile("C:\\somefile.txt");
// Delete the blob if it exists, using an asynchronous call.
myBlob.BeginDeleteIfExists(Eg_DeleteIfExistsCallback, myBlob);
}
private void Eg_DeleteIfExistsCallback(IAsyncResult result)
{
CloudBlob blobToDelete = (CloudBlob)result.AsyncState;
blobToDelete.EndDeleteIfExists(result);
}
| |
Remarks
A blob that has snapshots cannot be deleted unless the snapshots are also deleted. If a blob has snapshots, specify the options parameter, setting the DeleteSnapshotsOption property to specify how the snapshots should be handled when the blob is deleted.