Question

Does anyone know of examples which show how to encrypt a dataset at the client side and send it over to a web service and have it decrypted there?

Another question: What i need to do is a send hundreds of rows of data from a client to a web service and have the web service update the database with these records. I can’t think of any other way to do this without using a dataset. Is there a better method?

Thanks in advance!

Answer 1

As far as the encryption is concerned, why try to reinvent the wheel? Just connect to the webservice over SSL – it’ll most likely be much safer than a homegrown alternative.

I would probably create a custom struct/object and send an array of those to the webservice rather than a DataSet. It will mean (slightly) less network traffic; it will make the webservice’s WSDL more descriptive; and it will make it easier for any non-Microsoft apps to talk to the webservice, if that becomes necessary in the future.

EDIT: An example…

At the server-side you can declare a custom type (eg, ExampleUser), and then setup your method to accept an array of that type instead of a DataSet:

[WebService(Namespace='http://example.yourdomain.com/ExampleWebService/')] public class ExampleWebService : System.Web.Services.WebService {     // this is your custom type     public class ExampleUser     {         public int UserID { get; set; }         public string Name { get; set; }         public DateTime DateOfBirth { get; set; }     }      // this is your method     // accepts an array of ExampleUser rather than a DataSet     [WebMethod]     public void UploadUsers(ExampleUser[] usersArray)     {         // do something...     } } 

In the client application you would add a reference to the webservice. This will enable you to use the ExampleUser type declared in the server-side code above.

You could then just convert your DataSet to an array of ExampleUser objects before sending it to the webservice:

// get the number of rows in the DataTable int rowCount = yourDataSet.Tables[0].Rows.Count;  // create an array of ExampleUser with the correct capacity ExampleWebService.ExampleUser[] usersArray =     new ExampleWebService.ExampleUser[rowCount];  // iterate through each row in the table for (int i = 0; i < rowCount; i++) {     DataRow dr = yourDataSet.Tables[0].Rows[i];      // create an ExampleUser object and populate it from the DataRow columns     ExampleWebService.ExampleUser eu = new ExampleWebService.ExampleUser();     eu.UserID = (int)dr['User_ID'];     eu.Name = (string)dr['Name'];     eu.DateOfBirth = (DateTime)dr['Date_Of_Birth'];      // add the ExampleUser object to the array     usersArray[i] = eu; }  // the array is populated so let's call the webservice ExampleWebService.UploadUsers(usersArray); 

EDIT: Another example…

If you’re using .NET 3.5 then you can get the client-side down to just a few lines of code by using LINQ and object initialisers to create your array:

// create and populate the array ExampleWebService.ExampleUser[] usersArray =     yourDataSet.Tables[0].AsEnumerable().Select     (         s => new ExampleWebService.ExampleUser()         {             UserID = (int)s['User_ID'],             Name = (string)s['Name'],             DateOfBirth = (DateTime)s['Date_Of_Birth']         }     ).ToArray();  // the array is populated so let's call the webservice ExampleWebService.UploadUsers(usersArray);