Skip to main content

One way to persist objects in isolated storage

In unele cazuri avem nevoie sa stocam date in isolated storage. In cazul in care numarul de date pe vrem sa le stocam nu este foarte mare, putem sa le serializam direct si sa le salvam sub forma unui fisier in isolated storage.
In exemplul de mai jos, datele le-am serializat folosind DataContractSerializer. Din aceasta cauta, clasele pe care vrem sa le salvam trebuie sa fie decorate cu atributul DataContract, iar fiecare proprietate pe care dorim sa o salvam trebuie decorata cu atributul DataMember.
[DataContract]
class Foo
{
   [DataMember]
   public string Name { get; set; }
   public int Age {get; set; }
}
In exemplul dat mai sus o sa salvam doar proprietatea Name.
Mai jos puteti sa gasiti o clasa generica care salveaza un obiect dat. In metodele Save si Load as fi putut sa trimit ca si parametru numele la fisier, dar am ales ca numele de fisier sa se genereze pe baza tipului. Se poate si in alte moduri.
public class IsolatedStorageRepository<TItem>
   {
       public void Save(TItem item)
       {
           using (IsolatedStorageFileStream fileStream = IsolatedStorageFile.GetUserStoreForApplication()
                                                           .OpenFile(GetFileName(), FileMode.Create))
           {
               new DataContractSerializer(typeof(TItem))
                       .WriteObject(fileStream, item);
           }
       }
       public TItem Load()
       {
           IsolatedStorageFile storageFile = IsolatedStorageFile.GetUserStoreForApplication();
           if (!storageFile.FileExists(filename))
           {
               return default(TItem);
           }

           using (IsolatedStorageFileStream fileStream = storageFile.OpenFile(GetFileName, FileMode.Open))
           {
               return (TItem)new DataContractSerializer(typeof(TItem)).ReadObject(fileStream);              
           }
       }

       private string GetFileName()
       {
           string typeName = typeof (TItem).ToGenericFullName();
           typeName = typeName.Replace('<', '_');
           typeName = typeName.Replace('>', '_');

           return typeName;
       }
   }
Metoda ToGenericFullName imi returneaza numele unui obiect. Pentru a vedea implementarea acestei clase puteti sa intrati pe link-ul urmator: http://vunvulearadu.blogspot.com/2012/03/how-to-get-friendly-format-for.html
List<Foo> fooList = new List<Foo>();
// populate list
IsolatedStorageRepository repository = new IsolatedStorageRepository<List<Foo>>();
// Save list
repository.Save(fooList);
// Load list
repository.Load();
Solutia se poate implementa in diferite moduri. Aceasta este doar o varianta.
Enjoy!.

Comments

Popular posts from this blog

Windows Docker Containers can make WIN32 API calls, use COM and ASP.NET WebForms

After the last post , I received two interesting questions related to Docker and Windows. People were interested if we do Win32 API calls from a Docker container and if there is support for COM. WIN32 Support To test calls to WIN32 API, let’s try to populate SYSTEM_INFO class. [StructLayout(LayoutKind.Sequential)] public struct SYSTEM_INFO { public uint dwOemId; public uint dwPageSize; public uint lpMinimumApplicationAddress; public uint lpMaximumApplicationAddress; public uint dwActiveProcessorMask; public uint dwNumberOfProcessors; public uint dwProcessorType; public uint dwAllocationGranularity; public uint dwProcessorLevel; public uint dwProcessorRevision; } ... [DllImport("kernel32")] static extern void GetSystemInfo(ref SYSTEM_INFO pSI); ... SYSTEM_INFO pSI = new SYSTEM_INFO(...

How to audit an Azure Cosmos DB

In this post, we will talk about how we can audit an Azure Cosmos DB database. Before jumping into the problem let us define the business requirement: As an Administrator I want to be able to audit all changes that were done to specific collection inside my Azure Cosmos DB. The requirement is simple, but can be a little tricky to implement fully. First of all when you are using Azure Cosmos DB or any other storage solution there are 99% odds that you’ll have more than one system that writes data to it. This means that you have or not have control on the systems that are doing any create/update/delete operations. Solution 1: Diagnostic Logs Cosmos DB allows us activate diagnostics logs and stream the output a storage account for achieving to other systems like Event Hub or Log Analytics. This would allow us to have information related to who, when, what, response code and how the access operation to our Cosmos DB was done. Beside this there is a field that specifies what was th...

Cloud Myths: Cloud is Cheaper (Pill 1 of 5 / Cloud Pills)

Cloud Myths: Cloud is Cheaper (Pill 1 of 5 / Cloud Pills) The idea that moving to the cloud reduces the costs is a common misconception. The cloud infrastructure provides flexibility, scalability, and better CAPEX, but it does not guarantee lower costs without proper optimisation and management of the cloud services and infrastructure. Idle and unused resources, overprovisioning, oversize databases, and unnecessary data transfer can increase running costs. The regional pricing mode, multi-cloud complexity, and cost variety add extra complexity to the cost function. Cloud adoption without a cost governance strategy can result in unexpected expenses. Improper usage, combined with a pay-as-you-go model, can result in a nightmare for business stakeholders who cannot track and manage the monthly costs. Cloud-native services such as AI services, managed databases, and analytics platforms are powerful, provide out-of-the-shelve capabilities, and increase business agility and innovation. H...