C# Azure Blob Storage / Get blob size

Question

I've started work on Azure Storage. I've implemented create/delete container, create/delete/isExist blob functionalities. But I'm struck in find current Blob size from Azure Storage.

I've made lots of research but I'm not able to find any reasonable solution.

Here is my function to Get Size of Blob:

public long GetBlockBlobSize(string containerName, string blobName)
        {
            try
            {
                CloudBlobContainer container = _blobClient.GetContainerReference(containerName);
                var blockBlob = container.GetBlockBlobReference(blobName);
                return blockBlob.Properties.Length;
            }
            catch (Exception ex)
            {
                throw;
            }
        }

blockBlob.Properties.Length value is -1.

• Is there anything wrong on this approach?
• Is there a better approach available?

Thanks!

Answer 1

Please change your code to:

public long GetBlockBlobSize(string containerName, string blobName)
{
    try
    {
        CloudBlobContainer container = _blobClient.GetContainerReference(containerName);
        var blockBlob = container.GetBlockBlobReference(blobName);
        blockBlob.FetchAttributes();
        return blockBlob.Properties.Length;
    }
    catch (Exception ex)
    {
        throw;
    }
}

Essentially your code is simply creating an instance of CloudBlockBlob on the client side and thus the properties are initialized with default values. When you call FetchAttributes method, actual properties of the blob will be fetched from Azure Storage.