迁移Azure SDK 1.6表存储和写/读实体处理程序

Question

有一些使用Azure SDK 1.6的遗留代码，我的任务是更新到最新的/2.7。下面是保存实体的快速示例。注意，我们似乎使用了自己的自定义序列化器。我知道如何转换到新的CloudTable进行基本的读/写，但我不确定如何移植我们正在使用的序列化/反序列化逻辑。

 internal class FaultyMessageRecord : TableServiceEntity {
    public DateTime Created { get; set; }
    public Byte[ ] Content { get; set; }
}
public void StoreMessage( FaultyMessage faultyMessage ) {
        var context = tableClient.GetDataServiceContext( );
        context.WritingEntity += ( o, e ) => entrySerializer.WritingEntity( e );
        var now = DateTime.UtcNow;
        context.AddObject( tableName, new FaultyMessageRecord {
            PartitionKey = "",
            RowKey = now.ToString( "s" ), //sortable datetime
            Content = (byte[])faultyMessage.TransportMessageContent,
            Created = now
        } );
    }

部分移植代码:

 internal class FaultyMessageRecord : TableEntity {
    public DateTime Created { get; set; }
    public Byte[ ] Content { get; set; }
}
public void StoreMessage( FaultyMessage faultyMessage ) {           
        var table = tableClient.GetTableReference(tableName);
        var now = DateTime.UtcNow;
        var insertOperation = TableOperation.Insert(new FaultyMessageRecord
        {
            PartitionKey = "",
            RowKey = now.ToString("s"), //sortable datetime
            Content = (byte[]) faultyMessage.TransportMessageContent,
            Created = now
        });
        table.Execute(insertOperation);          
    }

Reading似乎有一个类似的逻辑，我可以在必要时提供，但基本上它使用上下文。ReadingEntity传入反序列化器

下面是序列化器类的表示:

public class UntypedAtomSerializer {

protected string[ ] hardcodedProperties;
  public UntypedAtomSerializer( params string[ ] hardcodedProperties ) {
     this.hardcodedProperties = hardcodedProperties;
  }

  public void WritingEntity( System.Data.Services.Client.ReadingWritingEntityEventArgs e ) {
            var propertyEl = e.Data
                .Elements( ).Where( el => el.Name.LocalName == "content" )
                .Elements( ).Where( el => el.Name.LocalName ==  "properties" )
                .FirstOrDefault( );
            SerializeProperties( e.Entity, propertyEl );
  }
  private void SerializeProperties( object tableEntry, XElement propertyEl ) {
            SerializeProperties( tableEntry, propertyEl, this.hardcodedProperties );
  }

  private static void SerializeProperties( object entry, XElement propertyEl, params string[ ] hardcodedProperties ) {
            var tableEntry = entry as IDictionaryEntity;
            if ( tableEntry != null ) {
                var elNS = XNamespace.Get( BaseAtomSerializer.WCF_DATA_NAMESPACE );
                var attrNS = XNamespace.Get( BaseAtomSerializer.WCF_METADATA_NAMESPACE );
                //add any properties that are part of the BaseStorageEntity dictionary
                foreach ( var kvp in tableEntry.ExtraProperties.Where( kvp => !hardcodedProperties.Contains( kvp.Key ) ) ) {
                    var newEl = new XElement( XName.Get( kvp.Key, elNS.NamespaceName ), kvp.Value );
                    if ( kvp.Value == null )
                        newEl.Add( new XAttribute( XName.Get( "null", attrNS.NamespaceName ), "true" ) );
                    else
                        newEl.Add( new XAttribute( XName.Get( "type", attrNS.NamespaceName ), BaseAtomSerializer.MapCLRtoAtomType( kvp.Value.GetType( ) ) ) );
                    propertyEl.Add( newEl );
                }
            }
  }
}

并且它被实例化为UntypedAtomSerializer entrySerializer = new UntypedAtomSerializer( "PartitionKey", "RowKey", "Timestamp", "Created", "Content" );，供上面的StoreMessage方法使用。

Answer 1

如果您很难保持对Atom的相同功能和依赖，则可以通过CloudTableClient实例上的GetTableServiceContext()方法获得表服务上下文。注意，您需要设置格式以使用Atom(. format . useatom()方法)。Context具有相同的WritingEntity和ReadingEntity事件处理程序。

然而，这些api已经过时了。我们建议使用ITableEntity/TableEntity的ReadEntity和WriteEntity方法。如果你有不能从ITableEntity派生的第三方对象，你可以参考下面的博客文章来序列化它们:http://blogs.msdn.com/b/windowsazurestorage/archive/2013/09/07/announcing-storage-client-library-2-1-rtm.aspx