DataServiceContext.CreateQuery<T> Method

.

$assembly = [Reflection.Assembly]::LoadFile("Microsoft.WindowsAzure.StorageClient.dll")

$blobCreds = New-Object Microsoft.WindowsAzure.StorageCredentialsAccountAndKey("---storage-account---","---storage-key---")
$account = New-Object Microsoft.WindowsAzure.CloudStorageAccount($blobCreds,$false)$tableclient = [Microsoft.WindowsAzure.StorageClient.CloudStorageAccountStorageClientExtensions]::CreateCloudTableClient($account)

$dataServiceContext = $tableclient.GetDataServiceContext()

#
# create a type on the fly to bing the 3 well-known required properties
# PartitionKey, RowKey, DateTime
# Also, save the full XML of the entity in a different property
#
add-type -ReferencedAssemblies @("System.Xml","System.Xml.Linq") @"
public partial class TElement {   private string _PartitionKey;
   private string _RowKey;
   private System.DateTime _Timestamp;
   public string PartitionKey { get { return _PartitionKey; } set { _PartitionKey = value; } }
   public string RowKey { get { return _RowKey; } set { _RowKey = value; } }
   public System.DateTime Timestamp { get { return _Timestamp; } set { _Timestamp = value; } }   private System.Xml.Linq.XElement _XElement;
   public System.Xml.Linq.XElement XElement { get { return _XElement; } set { _XElement = value; } }
}
"@

#
# Create and set an event handler.
# this event-handler is invoked before deserialization.
# the event-handler saves the original XML as a property of the TElement instance
#
$readHandler = [System.EventHandler[System.Data.Services.Client.ReadingWritingEntityEventArgs]] {   
    param([System.Object]$sender, [System.Data.Services.Client.ReadingWritingEntityEventArgs]$eventArgs);    [TElement]$entity = [TElement]$eventArgs.Entity;
    $entity.XElement  = $eventArgs.Data;
}
$dataServiceContext.add_ReadingEntity($readHandler)

#
# generate a closed method from a generic method.
# the usual examples use a class derived from Microsoft.WindowsAzure.StorageClient.TableServiceEntity.
# System.Xml.Linq does a reflection-based binding, and does not care as long as we provide
# a type with 3 required settable properties
#
$method = [Microsoft.WindowsAzure.StorageClient.TableServiceContext].GetMethod("CreateQuery")
$closedMethod = $method.MakeGenericMethod([TElement])

#
# invoke the selection method on the table named `WADPerformanceCountersTable` and hold onto the collection
# the collection is lazy-enumerated anyway
#
$collection = $closedMethod.Invoke($dataServiceContext,"WADPerformanceCountersTable")