how to access an XAML control from code

here is the class with the changes

public class Viapoints : INotifyPropertyChanged

    {
        private string _simpleAddress;
        private string civicNumber;
        private string civicName;
        private string civicCity;
        private string civicPostalCode;
        private string civicProvince;
        private string viaType;

       
        public Viapoints()
        { 
        
        
        }

        public Viapoints(string simpleAddress, string viatype)
        {
            this._simpleAddress = simpleAddress;
            this.ViaType = viatype;


        }
        public Viapoints(string cnumber, string cname, string ccity,string cpostalcode, string cprovince)
        {
            this.civicNumber = cnumber;
            this.civicName = cname;
            this.civicCity = ccity;
            this.civicPostalCode = cpostalcode;
            this.civicProvince = cprovince;
        }

        public string SimpleAddress
        {
            get { return _simpleAddress; }
            set { _simpleAddress = value;
            NotifyPropertyChanged();
            }

        }
        public string ViaType
        {
            get { return viaType; }
            set { viaType = value; }

        }
        public string CivicNumber
        {
            get { return civicNumber; }
            set { civicNumber = value; }
        }

        public string CivicName
        {
            get { return civicName; }
            set { civicName = value; }
        }

        public string CivicCity
        {
            get { return civicCity; }
            set { civicCity = value; }
        }

        public string CivicPostalCode
        {
            get { return civicPostalCode; }
            set { civicPostalCode = value; }
        }

        public string CivicProvince
        {
            get { return civicProvince; }
            set { civicProvince = value; }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

       
    }