GetBytes in C# not returning correct value

Question

I have a method that execute stored procedure and returns values of that stored procedure. I have a VIN that in SQL is in VarBinary type. I am not sure what can I use to get the value.

This is my code:

    // Get Customer Product By CustomerID
    public Model.CustomerProduct Get_CustomerProduct(int Customer_ID)
    {
        Model.CustomerProduct model = null;

        string myConnection = System.Configuration.ConfigurationManager.ConnectionStrings[connectionName].ToString();
        SqlDatabase db = new SqlDatabase(myConnection);
        int bufferSize = 100;                   

        byte[] outByte = new byte[bufferSize];  
        using (DbCommand command = db.GetStoredProcCommand("Get_Customer_Product"))
        {
            db.AddInParameter(command, "Customer_ID", DbType.Int32, Customer_ID);

            var result = db.ExecuteReader(command);

            try
            {
                if (result.FieldCount == 0)
                    model = null;
                else
                {
                    result.Read();
                    model = new Model.CustomerProduct()
                    {
                       Product_Name = result.GetString(2)
                      ,VIN =result.GetBytes(3,0,outByte,0,bufferSize)   // this return me wrong 



                    };
                }
            }
            catch (Exception ex)
            {


            }
            return model;
        }
    }

My problem is this line:

     VIN =result.GetBytes(3,0,outByte,0,bufferSize) 

This is returning 44 however the value that is suppose to return is:

0x00D1CCE9771AE7554D479F7B93A45611010000004158D130E5097EF2924DEC4C6255E5BAF4C8EF4C2AC2A8FD9F29295F41DA3550123C6C4575788F5E6

Answer 1

The GetBytes method returns the number of bytes it has written to the array, not the bytes themselves. Have a look at the contents of outByte and you should find your data there.

I would also suggest you first call GetBytes with a null buffer. This will cause it to return the length of the field, allowing you to size your buffer properly:

int len = result.GetBytes( 3, 0, null, 0, 0 );
byte[] buf = new byte[len];
result.GetBytes( 3, 0, buf, 0, buf.Length );

model = new Model.CustomerProduct()
{
    Product_Name = result.GetString(2),
    VIN = buf
};

If the code you have now runs, you most likely will have to change the type of VIN to a byte[] too.