Using Flags Features in C#

For example: I have the following requirement. When I want to obtain user information, I will first look up from the local cache, then look up from the distributed cache, and finally I can't find it and then query from the database. But in some scenarios I don't need to query the database.

So I want to build a model like this.

public UserEntity  GetUserInfo(List&lt;DataSource&gt;  dataSources)
{
    var xxxx = new UserEntity();
    if(()
    {
        //Fetch from local cache        return xxxx;
    }
 
    if(()
    {
        //Get from distributed cache        //Update local cache        return xxxx;
    }
 
    if(()
    {
        //Get from DB        //Update distributed cache        //Update local cache    }
    return xxxx;
}

However, it is more troublesome to build a List every time the caller will build a List. At this time, we can use the Flags feature in the enumeration and modify the program as follows:

First of all, the definition of enumeration, add the [Flags] feature tag, and the definition is generally to the n-power of 2, mainly to facilitate displacement operation

/// &lt;summary&gt;
/// Where to get data/// &lt;/summary&gt;
[Flags]
public enum DataSource
{
    /// &lt;summary&gt;
    /// Local cache    /// &lt;/summary&gt;
    [Description("Local Cache")]
    LocalCache = 1,
 
    /// &lt;summary&gt;
    /// Distributed Cache    /// &lt;/summary&gt;
    [Description("Distributed Cache")]
    DistributeCache = 2,
 
    /// &lt;summary&gt;
    ///     database    /// &lt;/summary&gt;
    [Description("database")]
    DB = 4,
}

Modify the code:

public UserEntity  GetUserInfo(DataSource dataSources)
{
    var xxxx = new UserEntity();
    if(()
    {
        //Fetch from local cache        return xxxx;
    }
 
    if(()
    {
        //Get from distributed cache        //Update local cache        return xxxx;
    }
 
    if(()
    {
        //Get from DB        //Update distributed cache        //Update local cache    }
    return xxxx;
}

The place where the call can be specified by "|", for example, I just want to use distributed cache and database, then:

var userInfo = GetUserInfo( | );

The above is all the content of this article. I hope it will be helpful to everyone's study and I hope everyone will support me more.