Skip to main content

How to store an array of booleans in a int

Uneori ajungem sa ne dorim sa stocam intr-un int mai multe valori booleene( de obicei de dragul artei) pentru a salva a avea mesajele care se trimit pe tiava cat mai mici. O solutie pe care o propun este sa folosim BitArray.
Acesta ne permite sa lucram cu biti. Pentru a initializa si seta valoriile unui BitArray trebuie sa scriem urmatorul cod:  
BitArray bits = new BitArray(32); // 32 - numarul de biti pe care il ocupa un int 
bits[0] = true;
bits[31] = false; 
Urmatorul pas este sa convertim un BitArray in int. Acest lucru se face destul de usor cu metoda CopyTo:  
int[] valueConverted = new int[1];
bits.CopyTo(valueConverted,0); // 0 - reprezinta indexul de inceput 
int result = valueConverted[0]; 
In result am obtinut int-ul care contine BitArrat-ul nostru.Pentru a executa procesul invers, sa obtinem un BitArray dintr-un int este nevoie sa apelam metoda statica GetBytes a clasei BitConverter.  
BitArray bits = BitConverter.GetBytes(result); 
Ce alta solutie aveti pentru aceast task?


  1. In functie de context, as folosi Enum-uri decorate cu [Flags]. Sint mult mai intuitive, in ciuda suportului dectul de slab de lucru cu ei in C#. Sincer, nici nu stiam de BitArray. Mersi.

  2. Eh, bitarrays, flags.. :)
    Ne obisnuim lenesi si uitam de un banal
    int bits |= 1 << pos;
    ca sa "stocam" un bit
    si (bits & 1< 0
    ca sa ii aflam valoarea..


  3. Normal, mai sus corect era:
    int bits = 0;
    bits |= 1 << pos;
    if (bits & (1 << pos) != 0) ...


Post a Comment

Popular posts from this blog

How to check in AngularJS if a service was register or not

There are cases when you need to check in a service or a controller was register in AngularJS.
For example a valid use case is when you have the same implementation running on multiple application. In this case, you may want to intercept the HTTP provider and add a custom step there. This step don’t needs to run on all the application, only in the one where the service exist and register.
A solution for this case would be to have a flag in the configuration that specify this. In the core you would have an IF that would check the value of this flag.
Another solution is to check if a specific service was register in AngularJS or not. If the service was register that you would execute your own logic.
To check if a service was register or not in AngularJS container you need to call the ‘has’ method of ‘inhector’. It will return TRUE if the service was register.
if ($injector.has('httpInterceptorService')) { $httpProvider.interceptors.push('httpInterceptorService&#…

ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded

Today blog post will be started with the following error when running DB tests on the CI machine:
threw exception: System.InvalidOperationException: The Entity Framework provider type 'System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer' registered in the application config file for the ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded. Make sure that the assembly-qualified name is used and that the assembly is available to the running application. See for more information. at System.Data.Entity.Infrastructure.DependencyResolution.ProviderServicesFactory.GetInstance(String providerTypeName, String providerInvariantName) This error happened only on the Continuous Integration machine. On the devs machines, everything has fine. The classic problem – on my machine it’s working. The CI has the following configuration:

TeamCity.NET 4.51EF 6.0.2VS2013
It seems that there …

Entity Framework (EF) TransactionScope vs Database.BeginTransaction

In today blog post we will talk a little about a new feature that is available on EF6+ related to Transactions.
Until now, when we had to use transaction we used ‘TransactionScope’. It works great and I would say that is something that is now in our blood.
using (var scope = new TransactionScope(TransactionScopeOption.Required)) { using (SqlConnection conn = new SqlConnection("...")) { conn.Open(); SqlCommand sqlCommand = new SqlCommand(); sqlCommand.Connection = conn; sqlCommand.CommandText = ... sqlCommand.ExecuteNonQuery(); ... } scope.Complete(); } Starting with EF6.0 we have a new way to work with transactions. The new approach is based on Database.BeginTransaction(), Database.Rollback(), Database.Commit(). Yes, no more TransactionScope.
In the followi…