Traverse all sites in SharePoint Online using C# CSOM.

CS-CSOM_Traverse_All_Sites_SPO.txt

List <SiteProperties> list = new List <SiteProperties>();

SPOSitePropertiesEnumerable ssp = null;
SPOSitePropertiesEnumerableFilter sspFilter = new SPOSitePropertiesEnumerableFilter();
SharePointOnlineCredentials creds = new SharePointOnlineCredentials("myUsernameGoesHere", securePassword);

using (ClientContext cc = new ClientContext("myURLGoesHere"))
{
    cc.Credentials = creds;

    String nextIndex = null;
    Tenant tenant = new Tenant(cc);

    //loop through all site collections including personal sites (even though not being used)
    //borrowed this code from after decompiling SPO Management Shell assemblies
    sspFilter.IncludePersonalSite = PersonalSiteFilter.Include;
    sspFilter.IncludeDetail = true;

    do
    {
        sspFilter.StartIndex = nextIndex;
        ssp = tenant.GetSitePropertiesFromSharePointByFilters(sspFilter);

        cc.Load(ssp);
        cc.ExecuteQuery();

        list.AddRange(ssp);
        nextIndex = ssp.NextStartIndexFromSharePoint;
    }while(nextIndex != null);

    foreach (SiteProperties sp in list)
    {
        //DO YOUR WORK HERE FOR EACH SITE COLLECTION, such as looping through subwebs
        cc.Load(cc.Web, w => w.NoCrawl,
                                    w => w.Webs,
                                    w => w.Url);
        cc.ExecuteQuery();

        //check subweb(s)
        foreach (var subweb in cc.Web.Webs)
        {
            cc.Load(subweb, sw => sw.NoCrawl,
                                        sw => sw.Url);
            cc.ExecuteQuery();
        }
    }
}