how to reference a collection object in another class

[tatinccr]

Hi guys,
I have a collection in a class, and I have another class and I need to reference this collection in another class. How can I do that? This is my code:

 
namespace CashRegister.Reports
{
     public partial class CustLevelReportPrint : Window
    {
      public CustLevelReportPrint(string zipfrom, string zipto, int catId,
         string custNumber, bool sortbyzip, bool sortbyname, bool sortbycat)
               {
                 InitializeComponent();
                 Customers = CustLabels.LoadDatas(zipfrom, zipto, catId,     <--- HERE I FILL MY COLLECTION
                                      custNumber, sortbyzip, sortbyname, sortbycat);
                 this.DataContext = this;
               }
 
         public List<CustLabels> Customers { get; set; }   <--- HERE I DECLARE THE COLLECTION
}
 
public class CustLabelConverter : IValueConverter
{
      int i ,j = 0;
      StringBuilder Line1 = new StringBuilder();
      StringBuilder Line2 = new StringBuilder();
      StringBuilder Line3 = new StringBuilder();
      StringBuilder theLabelText = new StringBuilder();
      public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
     {     <--- HERE I NEED TO REFERENCE THE COLLECTION
E.G  i = Customers.Count;
        string cad;
 
        if (value == null || !(value is CustLabels))
          {
             if (theLabelText.ToString() == string.Empty)
                return Binding.DoNothing;
             else
                return theLabelText.ToString();
         }
         if (i < 3)
         {
             CustLabels val = value as CustLabels;
 
             cad = (val.Name.ToString().Length > 50 ? val.Name.ToString().Substring(0, 50) : val.Name.ToString();
             Line1.AppendFormat(cad + "\t");
             cad = (val.Address.ToString().Length > 50 ? val.Address.ToString().Substring(0, 50) : val.Address.ToString());
             Line2.AppendFormat(cad + "\t");
             cad = val.City.ToString().Trim() + ", " + val.State.ToString().Trim() + ", " + val.ZipCode.ToString().Trim(); 
             cad = (cad.Length > 50 ? cad.ToString().Substring(0, 50) : cad.ToString().PadRight(50));
             Line3.AppendFormat(cad + "\t");
             i++;
             if (i == 3)
             {
                i = 0;
                theLabelText.AppendFormat("{0}" + Line1.ToString(), Environment.NewLine);
                theLabelText.AppendFormat("{0}" + Line2.ToString(), Environment.NewLine);
                theLabelText.AppendFormat("{0}" + Line3.ToString(), Environment.NewLine);
                Line1.Remove(0, Line1.Length);
                return theLabelText.ToString();
            }
            else
               return Binding.DoNothing;
           }
        else
         {
           i = 0;
           return theLabelText.ToString();
         }
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
       return Binding.DoNothing;
}
}
 

[Sfreak]

You didnt define your CustLabels class there to show us where is the List attribute. I will show an usual example and tell me if is not the case.

public class Address
{
    public string Street {get; set;}
    public string City   {get; set;}
}
public class Customer
{
    public string        Name    {get; set;}
    public int           Age     {get; set;}
    public List<Address> Address {get; set;}
}
The usual operation is:
 
public List<Address> AddressList()
{
   List<Address> lst = new List<Address>();
   Address  address  = new Address();
   address.Street    = "Paranagua";
   address.City      = "Londrina";
   lst.Add(address);
 
   Address  address2  = new Address();
   address2.Street    = "Brazil";
   address2.City      = "Londrina";
   lst.Add(address2);
 
   return lst;
}
 
public void CreateCustomer()
{
   Customer customer = new Customer();
   customer.Name     = "Fernando Mello";
   customer.Age      = 29;
   customer.Address  = AddressList();
}

I think you are trying to cast a third object into Address class and then bind into "customer.Address" list right?

Ok here we go. I suppose you have a DTO class (Data Transfer Object).

public class DTOCustomer
{
   public string Name   {get; set;}
   public string Age    {get; set;}
   public string Street {get; set;}
   public string City   {get; set;}
   // and some other attributes
}
public Address AddressConverter(DTOCustomer dto)
{
   Address address = new Address();
   address.Street  = dto.Street;
   address.City    = dto.City;
   return address;
}

And then you have a compatible class to bind into your original class. Try to see how to use DTO classes, it might help you.

I hope it can help you.

Fernando Mello

[tatinccr]

@Sfreak
Fernando,
Thank you very much for responding. I have tried to instantiate the class but I get other errors
always related to null references. I send you the complete code to see if you can help.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Data;
using System.Data.SqlClient;
using System.ComponentModel;
using System.Globalization;
using System.Collections;
 
namespace CashRegister.Reports
{
    /// <summary>
    /// Interaction logic for CustLevelReportPrint.xaml
    /// </summary>
    public partial class CustLabelReportPrint : Window
    {
        public CustLabelReportPrint()
        { }
 
        public CustLabelReportPrint(int zipfrom, int zipto, int catId,
            string sortby)
        {
            InitializeComponent();
            Customers = CustLabels.LoadDatas(zipfrom, zipto, catId,
                sortby);
            this.DataContext = this;
        }
 
        public List<CustLabels> Customers { get; set; }
 
    }
 
    public partial class CustLabels : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
 
        private string _name;
        public string Name
        {
            get { return _name; }
            set
            {
                _name = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("Name"));
                }
            }
        }
 
        private string _address;
        public string Address
        {
            get { return _address; }
            set
            {
                _address = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("Address"));
                }
            }
        }
 
        private string _city;
        public string City
        {
            get { return _city; }
            set
            {
                _city = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("City"));
                }
            }
        }
 
        private string _state;
        public string State
        {
            get { return _state; }
            set
            {
                _state = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("State"));
                }
            }
        }
 
        private string _zipcode;
        public string ZipCode
        {
            get { return _zipcode; }
            set
            {
                _zipcode = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("ZipCode"));
                }
            }
        }
 
       public CustLabels(string name, string address, string city, string state,
             string zipcode)
        {
            Name = name;
            Address = address;
            City = city;
            State = state;
            ZipCode = zipcode;
        }
 
        public static List<CustLabels> LoadDatas(int zipfrom, int zipto, int category,
            string sortby)
        {
            List<CustLabels> list = new List<CustLabels>();
            string conn = Common.Common.GetConnectionString();
            using (SqlConnection con = new SqlConnection(conn))
            {
                try
                {
                    SqlCommand cmd = new SqlCommand("spCustomerLabelReport", con);
                    cmd.CommandType = CommandType.StoredProcedure;
                    //Parameters to Store Procedure
                    cmd.Parameters.Add("@Param_ZipCodeFrom", SqlDbType.Int);
                    cmd.Parameters["@Param_ZipCodeFrom"].Value = zipfrom;
                    cmd.Parameters.Add("@Param_ZipCodeTo", SqlDbType.Int);
                    cmd.Parameters["@Param_ZipCodeTo"].Value = zipto;
                    cmd.Parameters.Add("@Param_Category", SqlDbType.SmallInt);
                    cmd.Parameters["@Param_Category"].Value = category;
                    cmd.Parameters.Add("@Param_SortBy", SqlDbType.VarChar);
                    cmd.Parameters["@Param_SortBy"].Value = sortby;
 
                    con.Open();
                    SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                    while (dr.Read())
                    {
                        CustLabels custreporting = new CustLabels(dr["name"].ToString().Trim(),
                            dr["address"].ToString().Trim(), dr["city"].ToString().Trim(),
                            dr["state"].ToString().Trim(), dr["zip"].ToString().Trim());
                        list.Add(custreporting);
                    }
 
                    return list;
                }
                catch (SqlException ex)
                {
                    throw (ex);
                }
            }
        }
    }
 
    public class CustLabelConverter : IValueConverter
    {
        int i = 0 ,j = 0, k = 4;  //k representa la cantidad de elementos en la coleccion
        // Customers. Como la referencio aqui???
        StringBuilder Line1 = new StringBuilder();
        StringBuilder Line2 = new StringBuilder();
        StringBuilder Line3 = new StringBuilder();
        StringBuilder theLabelText = new StringBuilder();
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            string cad;
 
            if (value == null || !(value is CustLabels || value is IList))
            {
                if (theLabelText.ToString() == string.Empty)
                    return Binding.DoNothing;
                else
                    return theLabelText.ToString();
            }
            if (i < 3)
            {
                //IList cant = value as IList;
                CustLabels val = value as CustLabels;
 
                k = val.Cant;
                cad = (val.Name.ToString().Length > 50 ? val.Name.ToString().Substring(0, 50) : val.Name.ToString().PadRight(50));
                Line1.AppendFormat(cad + "\t");
                cad = (val.Address.ToString().Length > 50 ? val.Address.ToString().Substring(0, 50) : val.Address.ToString().PadRight(50));
                Line2.AppendFormat(cad + "\t");
                cad = val.City.ToString().Trim() + ", " + val.State.ToString().Trim() + ", " + val.ZipCode.ToString().Trim(); 
                cad = (cad.Length > 50 ? cad.ToString().Substring(0, 50) : cad.ToString().PadRight(50));
                Line3.AppendFormat(cad + "\t");
                i++;
                j++;
                if (i == 3)
                {
                    i = 0;
                    theLabelText.AppendFormat("{0}" + Line1.ToString(), Environment.NewLine);
                    theLabelText.AppendFormat("{0}" + Line2.ToString(), Environment.NewLine);
                    theLabelText.AppendFormat("{0}" + Line3.ToString(), Environment.NewLine);
                    theLabelText.AppendLine();
                    Line1.Remove(0, Line1.Length);
                    Line2.Remove(0, Line2.Length);
                    Line3.Remove(0, Line3.Length);
                    return Binding.DoNothing; // NtheLabelText.ToString();
                }
                else
                {
                    if (j == k)
                    {
                        theLabelText.AppendFormat("{0}" + Line1.ToString(), Environment.NewLine);
                        theLabelText.AppendFormat("{0}" + Line2.ToString(), Environment.NewLine);
                        theLabelText.AppendFormat("{0}" + Line3.ToString(), Environment.NewLine);
                        Line1.Remove(0, Line1.Length);
                        Line2.Remove(0, Line2.Length);
                        Line3.Remove(0, Line3.Length);
                        return theLabelText.ToString();
                    }
                    else
                        return Binding.DoNothing;
                }
            }
            else
            {
                i = 0;
                return theLabelText.ToString();
            }
        }
 
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return Binding.DoNothing;
        }
    }
}