Object reference not set to an instance of an object - webservices

Question

I have this error appearing in my web service and even though I'v had a look at the articles on the null issue, I am not able to find how to fix this error

this is my code:

    SendInvUpdate.InvServices.UpdateRatePackagesRequest urq = new SendInvUpdate.InvServices.UpdateRatePackagesRequest();
    SendInvUpdate.InvServices.UpdateRatePackagesOperationResponse ors = new SendInvUpdate.InvServices.UpdateRatePackagesOperationResponse();


    protected void Page_Load(object sender, EventArgs e)
    {
        Int64 HID = 819942;
        Int64 HRID = 154482;

        SendInvUpdate.InvServices.UpdateRatePackagesRequest request = new SendInvUpdate.InvServices.UpdateRatePackagesRequest();

        ChannelManagerAccount account = new ChannelManagerAccount();
        request.HotelId = HID;

        int avail = 4;
        DateTime frodte = Convert.ToDateTime("2012-04-12");
        DateTime todte = Convert.ToDateTime("2012-04-30");
        int NoofRatePackages = 3;
        UpdateRatePackageRequest[] RatePackages = new UpdateRatePackageRequest[NoofRatePackages];
        string res;
        request.RatePackages = new UpdateRatePackageRequest[NoofRatePackages];
        request.RatePackages = RatePackages;

        UpdateRatePackageRequest rp = new UpdateRatePackageRequest();

        for (int i = 0; i < NoofRatePackages; i++)
        {        
            rp.RatePackageId = HRID;        

            RateDetails[] Rates = new RateDetails[NoofRatePackages];

            rp.Rates = new RateDetails[NoofRatePackages];
            rp.Rates = Rates;

            RateDetails rd = new RateDetails();

            for (int j = 0; j < NoofRatePackages; j++)
            {
                rd.Availability = avail;

                rd.AvailabilityApplicationType = SendInvUpdate.InvServices.AvailabilityApplicationType.SET;

                rd.FromDate = frodte;

                rd.ToDate = todte;

            }

        }

       SendInvUpdate.InvServices.InventoryServiceClient icc = new SendInvUpdate.InvServices.InventoryServiceClient();            
        // ( *Line where the error appears*)
        ors = icc.UpdateRatePackages(request); 

        res = ors.Results.ToString();          
    }

I know that it has something to do with the RateDetails array and initialising the value of the RateDetails to that instant of request but I am not sure how or what to do with regards to that. In debug mode when looking at values of rp there are no values for rp.Rates[0],rp.Rates[1],rp.Rates[2] also RatePackages[0],RatePackages[1],RatePackages[2] are also null so I have a strong feeling thats where my problem is but I don't have a clue on how to fix.

Would be grateful for any sort of insight to where I've gone wrong!

Answer 1

Move the initialization of icc service reference inside your page_load code as

SendInvUpdate.InvServices.InventoryServiceClient icc = new SendInvUpdate.InvServices.InventoryServiceClient(); 
ors = icc.UpdateRatePackages(request); ( Line where the error appears)

I'm not an expert in asp.net but you can't base your code on global vars if you don't save them in some persistent container (search about SESSION, VIEWSTATE)

EDIT: also something seems wrong here

   UpdateRatePackageRequest[] RatePackages = new UpdateRatePackageRequest[NoofRatePackages]; 
   string res; 
   request.RatePackages = new UpdateRatePackageRequest[NoofRatePackages]; 
   request.RatePackages = RatePackages; 

should be only request.RatePackages = new UpdateRatePackageRequest[NoofRatePackages]; ?

EDIT2: You send to the InventoryServiceClient an object request that contains an array of UpdateRatePackageRequest, but after creation of the array you don't set any instance of UpdateRatePackageRequest. So I suppose the InventoryServiceClient fails when reading the values from the array. I will try to change your for loop in this way

   for (int i = 0; i < NoofRatePackages; i++)       
   {               
        UpdateRatePackageRequest rp = new UpdateRatePackageRequest(); 
        request.RatePackages[i] = rp;
        ....

Same error with RateDetails. You create the array, but don't set any value of your array with an actual instance of RateDetails

        for (int j = 0; j < NoofRatePackages; j++) 
        { 
            RateDetails rd = new RateDetails();  
            rp.Rates[j] = rd;
            ....