What is Membership Provider and how to implement it in ASP.Net

It's very simple really:

1. Create a new Class file (if you're not using a multi-layered system, in your project's Models folder) let's called MyMembershipProvider.cs

2. Inherit that class from System.Web.Security.MembershipProvider

3. automagically create the needed methods (period + space in the inherit class)

Done!

All methods will have the NotImplementedException exception, all you need to do is edit each one and put your own code, for example, I use for the GetUser:

public override MembershipUser GetUser(string username, bool userIsOnline)
{
    return db.GetUser(username);
}

dbis my Database Repository that I added into the class as

MyServicesRepository db = new MyServicesRepository();

there, you will find the GetUser method as:

public MembershipUser GetUser(string username)
{
    OS_Users user = this.FindUserByUsername(username);

    if (user == null)
        return
        new MembershipUser(
            providerName: "MyMembershipProvider",
            name: "",
            providerUserKey: null,
            email: "",
            passwordQuestion: "",
            comment: "",
            isApproved: false,
            isLockedOut: true,
            creationDate: DateTime.UtcNow,
            lastLoginDate: DateTime.UtcNow,
            lastActivityDate: DateTime.UtcNow,
            lastPasswordChangedDate: DateTime.UtcNow,
            lastLockoutDate: DateTime.UtcNow);

    return
        new MembershipUser(
            providerName: "MyMembershipProvider",
            name: user.username,
            providerUserKey: null,
            email: user.email,
            passwordQuestion: "",
            comment: "ANYTHING you would like to pass",
            isApproved: true,
            isLockedOut: user.lockout,
            creationDate: user.create_date,
            lastLoginDate: user.lastLoginDate,
            lastActivityDate: user.lastActivityDate,
            lastPasswordChangedDate: user.lastPasswordChangedDate,
            lastLockoutDate: user.lastLockoutDate);
}

Do this for all the methods you use (debug the project and see which ones you need) - I only use some, not all as I don't really care about methods like ChangePasswordQuestionAndAnswer, DeleteUser, etc

just make sure that in your web.config you add the new Membership as:

<membership defaultProvider="MyMembershipProvider">
  <providers>
    <clear/>
    <add name="MyMembershipProvider" type="Your.NameSpace.MyMembershipProvider" connectionStringName="OnlineServicesEntities"
         enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false"
         maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10"
         applicationName="/" />
  </providers>
</membership>