CloudPageBlob.ClearPages Method (Int64, Int64, BlobRequestOptions)

static void WriteToPageBlob(Uri blobEndpoint, string accountName, string accountKey)
{
    //Create service client for credentialed access to the Blob service.
    CloudBlobClient blobClient = 
        new CloudBlobClient(blobEndpoint, new StorageCredentialsAccountAndKey(accountName, accountKey));

    // create container if it does not exist
    CloudBlobContainer cloudContainer = blobClient.GetContainerReference("mypageblobs");
    cloudContainer.CreateIfNotExist();

    //Get a reference to the page blob that will be created.
    CloudPageBlob pageBlob = cloudContainer.GetPageBlobReference("apageblob");

    //Generate some data to write.  
    byte[] data = new byte[1024];
    Random rnd = new Random();
    rnd.NextBytes(data);

    //Create a 100 MB page blob.
    pageBlob.Create(100 * 1024 * 1024);

    //Write two sets of pages. Note that you can write 4 MB per call to WritePages().
    pageBlob.WritePages(new MemoryStream(data), 0);
    pageBlob.WritePages(new MemoryStream(data), 4096);

    //Populate the page blob's attributes.
    pageBlob.FetchAttributes();
    Console.WriteLine("Blob length = {0}", pageBlob.Properties.Length);

    //Print out the current range of pages.
    PrintPageRanges("Before write to 10240:", pageBlob);

    //Write another page.
    pageBlob.WritePages(new MemoryStream(data), 10240);

    //Print out the new range of pages.
    PrintPageRanges("After write to 10240:", pageBlob);

    //Clear a page.
    pageBlob.ClearPages(4096, 1024);

    //Print out the new range of pages.
    PrintPageRanges("After clearing page at 4096:", pageBlob);

    //Delete the page blob.
    pageBlob.Delete();
}

static void PrintPageRanges(string msg, CloudPageBlob cloudBlob)
{
    //Write out the page ranges for the page blob.
    IEnumerable<PageRange> ranges = cloudBlob.GetPageRanges();
            
    Console.Write("{0}:<", msg);
            
    foreach (PageRange range in ranges)
    {
        Console.Write(" [{0}-{1}] ", range.StartOffset, range.EndOffset);
    }

    Console.WriteLine(">");
}