Membership

// Creates a new membership object
MembershipInfo newMembership = new MembershipInfo();

// Sets the membership properties
newMembership.MembershipDisplayName = "New membership";
newMembership.MembershipName = "NewMembership";
newMembership.MembershipSiteID = SiteContext.CurrentSiteID;

// Saves the membership to the database
MembershipInfoProvider.SetMembershipInfo(newMembership);

// Gets the membership
MembershipInfo updateMembership = MembershipInfoProvider.GetMembershipInfo("NewMembership", SiteContext.CurrentSiteName);
if (updateMembership != null)
{
    // Updates the membership properties
    updateMembership.MembershipDisplayName = updateMembership.MembershipDisplayName.ToLower();

    // Saves the changes to the database
    MembershipInfoProvider.SetMembershipInfo(updateMembership);
}

// Gets all memberships whose name starts with 'NewMembership'
var memberships = MembershipInfoProvider.GetMemberships().WhereStartsWith("MembershipName", "NewMembership");

// Loops through individual memberships
foreach (MembershipInfo modifyMembership in memberships)
{
    // Updates the  membership properties
    modifyMembership.MembershipDisplayName = modifyMembership.MembershipDisplayName.ToUpper();

    // Saves the changes
    MembershipInfoProvider.SetMembershipInfo(modifyMembership);
}

// Gets the membership
MembershipInfo deleteMembership = MembershipInfoProvider.GetMembershipInfo("NewMembership", SiteContext.CurrentSiteName);

if (deleteMembership != null)
{
    // Deletes the membership
    MembershipInfoProvider.DeleteMembershipInfo(deleteMembership);
}

// Gets role and membership objects
RoleInfo role = RoleInfoProvider.GetRoleInfo("Rolename", SiteContext.CurrentSiteID);
MembershipInfo membership = MembershipInfoProvider.GetMembershipInfo("NewMembership", SiteContext.CurrentSiteName);

if ((role != null) && (membership != null))
{             
    // Adds the role to the membership
    MembershipRoleInfoProvider.AddMembershipToRole(membership.MembershipID, role.RoleID);
}

// Gets role and membership objects
RoleInfo role = RoleInfoProvider.GetRoleInfo("Rolename", SiteContext.CurrentSiteID);
MembershipInfo membership = MembershipInfoProvider.GetMembershipInfo("NewMembership", SiteContext.CurrentSiteName);

if ((role != null) && (membership != null))
{
    // Removes the role from the membership
    MembershipRoleInfoProvider.RemoveMembershipFromRole(membership.MembershipID, role.RoleID);
}

// Gets user and membership objects
UserInfo user = UserInfoProvider.GetUserInfo("Username");
MembershipInfo membership = MembershipInfoProvider.GetMembershipInfo("NewMembership", SiteContext.CurrentSiteName);

if ((user != null) && (membership != null))
{
    // Grants the membership to the user (valid for 3 minutes)
    MembershipUserInfoProvider.AddMembershipToUser(membership.MembershipID, user.UserID, DateTime.Now.AddMinutes(3));
}

// Gets user and membership objects
UserInfo user = UserInfoProvider.GetUserInfo("Username");
MembershipInfo membership = MembershipInfoProvider.GetMembershipInfo("NewMembership", SiteContext.CurrentSiteName);

if ((user != null) && (membership != null))
{
    // Removes the membership from the user
    MembershipUserInfoProvider.RemoveMembershipFromUser(membership.MembershipID, user.UserID);
}

// Gets the current user
UserInfo user = MembershipContext.AuthenticatedUser;

if (user != null)
{
    // Gets all valid memberships assigned to the user.
    // Requires a using statement for the 'System.Linq' namespace.
    // The boolean parameter of the IsInMembership method is set to true,
    // so both memberships on the current site and global memberships are loaded.
    var memberships = MembershipInfoProvider.GetMemberships()
        .Where(membership => user.IsInMembership(membership.MembershipName, SiteContext.CurrentSiteName, true));

    // Loops through the memberships
    foreach (MembershipInfo membership in memberships)
    {
        // Process the membership
    }
}