C# Discussion Boards - CodeProject

Re: Need to understand work assigned to me

nisss14-Dec-17 20:33

nisss

14-Dec-17 20:33

Thank you so much for guiding me rather than discouraging me.

Re: Need to understand work assigned to me

Gerry Schmitz14-Dec-17 22:48

Gerry Schmitz

14-Dec-17 22:48

Any time!

"Class" assignment (pardon the pun) or not, you get extra points for being able to carry on an intelligent conversation.

And I was "on call" the first 2 weeks into my first job; so those that can, do (the "fast immersion" track).

"(I) am amazed to see myself here rather than there ... now rather than then".
― Blaise Pascal

modified 15-Dec-17 5:12am.

HTTP GET

Member 1355170113-Dec-17 2:54

Member 13551701

13-Dec-17 2:54

Hope someone can share some knowledge.

I made a HttpPost method, which sent a list of ids to a method in my service. The method then compared the ids to a anothers list, and return the object, which does´t contain the ids from the post request.

Now I want to make a HTTP Get method, which get the object after they are sorted

<pre> public List<ProductBO> GetAll()
        {
            using (var uow = facade.UnitOfWork)
            {
                return uow.ProductRepository.GetAll().Select(p => Pconv.Convert(p)).ToList();
            }
        }
        public List<ProductBO> FilteretProduct(List<int> ids)
        {
            // Get all the product from the repository
            var AllProducts = GetAll();
            List<ProductBO> FilteredProducts = new List<ProductBO>();
            // Runs through the list of all the products of var AllProducts
            foreach (var prod in AllProducts)
            {
                //Runs through list ids that we get from the controller post request
                foreach (var id in ids)
                {
                    /*If: the IngredientIds(list of ids) of the current
                     * product doesn't contain the current id
                     * Then add that product to the 'FilteredProducts' List*/
                    if (!prod.IngredientIds.Contains(id))
                    {
                        FilteredProducts.Add(prod);
                    }
                }
            }
            //returning the list
            return FilteredProducts;
        }


<pre>
        // This post request, gets the ids, which are used in the FilteretProduct method.
        [HttpPost]
        [Route("FilteredProducts")]
        public List<ProductBO> FilteredList(List<int> ids)
        {
            List<ProductBO>filterProduct;
            return filterProduct = facade.ProductService.FilteretProduct(ids);


        }
        [HttpGet]
        [Route("GetFilteredProducts")]
        public List<ProductBO> GetFilteredList()
        {
            //The list from  above
            return filterProduct;


        }

Re: HTTP GET

Richard Deeming13-Dec-17 3:06

Richard Deeming

13-Dec-17 3:06

That doesn't make any sense. Web applications are stateless - they don't remember state from one request to the next. So even if you moved your local variable out of the POST method to make it available from the GET method, by the time you made the GET request, the content of the variable would have been lost.

You would need to use some form of session storage to persist the data between the requests. The precise details of how you do that will depend on how you're hosting your application, and whether you're using the full framework or .NET Core.

It's not clear why you would need two requests, when the POST request already returns the data?

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Re: HTTP GET

Member 1355170113-Dec-17 7:25

Member 13551701

13-Dec-17 7:25

thanks for the replay!
Normally I make a post request to insert some values and af get request to get some values.
I didn´t know you could do that with a post request ?

C# interface

Member 1212070811-Dec-17 1:23

Member 12120708

11-Dec-17 1:23

i have two interface with diffrent name but method name will same and i am consumming in a class both interface how i know which method will cll i1 method or i2 method

Re: C# interface

Pete O'Hanlon11-Dec-17 1:27

Pete O'Hanlon

11-Dec-17 1:27

What you are looking for is the difference between an implicit and explicit interface. There's a very good explanation here[^].

This space for rent

Voting System in C#

Member 1356906610-Dec-17 20:41

Member 13569066

10-Dec-17 20:41

How to make Voting system in C# that should be object oriented programming?

Re: Voting System in C#

Richard MacCutchan10-Dec-17 20:59

Richard MacCutchan

10-Dec-17 20:59

Gather the requirements, identify the inputs and outputs, design the user interface, and write and test the code.

Re: Voting System in C#

Member 1356906610-Dec-17 22:16

Member 13569066

10-Dec-17 22:16

first each user should save ther self with fingerprint scanner and then can vote to the candidates.
candidates must have photo and name

Re: Voting System in C#

Richard MacCutchan10-Dec-17 22:38

Richard MacCutchan

10-Dec-17 22:38

How to get an answer to your question - C# Discussion Boards[^]

Re: Voting System in C#

Pete O'Hanlon10-Dec-17 22:47

Pete O'Hanlon

10-Dec-17 22:47

Those aren't requirements; that's a vague wishlist. For instance, what types of photo id are you accepting? What happens if the fingerprint scanner breaks down? How are the candidate details stored? How do you vote for them?

This space for rent

Re: Voting System in C#

OriginalGriff10-Dec-17 23:32

OriginalGriff

10-Dec-17 23:32

And?
What have you done so far?
Where are you stuck?
What help do you need?

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Re: Voting System in C#

Mycroft Holmes10-Dec-17 23:39

Mycroft Holmes

10-Dec-17 23:39

OriginalGriff wrote:
What help do you need?

Well duh - send the codez NOW!

Never underestimate the power of human stupidity
RAH

Re: Voting System in C#

OriginalGriff10-Dec-17 23:43

OriginalGriff

10-Dec-17 23:43

That was my guess: "I want you to do my homework" but it'd be nice to know if he's genuine and wants to think or just waste his whole life ... Big Grin | :-D

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Re: Voting System in C#

phil.o11-Dec-17 18:02

phil.o

11-Dec-17 18:02

Democracy's in danger! Smile | :)

"I'm neither for nor against, on the contrary." John Middle

Generic type passed into method question

User987439-Dec-17 20:44

User98743

9-Dec-17 20:44

I'd like to start using more C# generics. Can someone tell me what the

<?>

portion of the method syntax below represents? Is it a placeholder for the object type? (see my example further down)

<Access Specifier> <Return Type> <Method Name><?>(Parameter List) 
{
   Method Body
}

I was wanting to do something like this, so that I could pass either an OLEDB DB Connection object or an SqlClient connection object.

private T DataConnection<T> ( T db_conn_obj , int index_of_mydatafile )
{
...
}

Re: Generic type passed into method question

OriginalGriff9-Dec-17 22:32

OriginalGriff

9-Dec-17 22:32

The "bit in the middle" is the indicator that this is a Generic method, and allows you to specify a substitution name which identifies where the generic class type is needed. It doesn't have to be <T> - you can use any valid identifier:

private TypeOfClass DataConnection<TypeOfClass>(TypeOfClass db_conn_obj, int index_of_mydatafile)
    {
    return db_conn_obj;
    }

But the convention is to use "T" as the generic class name.
The trouble with that is I can happily pass any class type to your method:

var x = DataConnection("hello", 666);

And it will work - additionally, You can't use any of the fields, properties, or methods of your Connection, even if you pass an SqlConnection object.

The solution is to apply a constraint:

private T DataConnection<T>(T db_conn_obj, int index_of_mydatafile) where T: System.Data.Common.DbConnection
    {
    Console.WriteLine(db_conn_obj.ConnectionString);
    db_conn_obj.Open();
    return db_conn_obj;
    }

Which limits the classes you can pass to those derived from DbConnection (which includes SqlConnection, OleDbConnection, and so forth:

var x = DataConnection(new SqlConnection(), 666);
var y = DataConnection(new OleDbConnection(), 666);

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Re: Generic type passed into method question

User9874310-Dec-17 0:49

User98743

10-Dec-17 0:49

This is a big help! I've been working on it for hours. I'm working on some existing code that I'm supposed to make work with both OleDbConnection as well as SqlConnection.

It's more of a training exercise for me, because it looks like it's going to take a lot of time to convert all of the db methods to use either connection.

So right now, I have an OleDbConnection, like so:

private OleDbConnection DataConnection ( int index_of_mydatafile )
{
    string dbpath = MyDataFiles[ index_of_mydatafile ];

    string conn_string = OledbProvider(dbpath) + "data source=" + dbpath;

    Debug.WriteLine ( conn_string );

    return new OleDbConnection ( conn_string );

}

The connection is just be declared and instantiated in a using statement like this:

using ( OleDbConnection dbConnection = DataConnection ( index_of_mydatafile ) )
			using ( OleDbCommand dbCommand = new OleDbCommand ( sql , dbConnection ) )
			using ( OleDbDataAdapter adapter = new OleDbDataAdapter ( dbCommand ) )

So the command object is actually opening the connection later. To get this working, I tried this, but I'm stuck at the new declaration, which is causing an error, presumably because I need to cast the T maybe? I'm just pulling things out of thin air now. lol

private T DataConnection<T> ( T db_conn_obj , int index_of_mydatafile ) where T : System.Data.Common.DbConnection
		{
			string dbpath = MyDataFiles[ index_of_mydatafile ];
			string provider = OledbProvider ( dbpath );
			string conn_string =  provider + "data source=" + dbpath;

			Debug.WriteLine ( conn_string );

			if ( provider == "" )
			{
				conn_string = @"Data Source= xxxx\xxxx;Initial Catalog=xxxx;Integrated Security=SSPI;Connect Timeout=5;ConnectRetryCount=0;ApplicationIntent=ReadWrite;"
			}
	
			return new T ( conn_string );
		}

Re: Generic type passed into method question

OriginalGriff10-Dec-17 0:57

OriginalGriff

10-Dec-17 0:57

Ah! To create a new instance, you need to tell it that the only classes that can be "generic-ed" are concrete classes (like OldedbConnection, and SqlConnection), not abstract classes like DbConnection.
That's easy: add the new constraint (and remove the class instance from the parameters list):

private T DataConnection<T>(int index_of_mydatafile) where T : System.Data.Common.DbConnection, new()
    {
    T db_conn_obj = new T();
    db_conn_obj.ConnectionString = "...";
    db_conn_obj.Open();
    return db_conn_obj;
    }

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Re: Generic type passed into method question

User9874310-Dec-17 1:05

User98743

10-Dec-17 1:05

Holy crap, man! That's freak'n awesome! It's a double ++ because the original code doesn't include the class instance in the parameters list.

This is the first time I actually posted a question on any programmer's forum. I wish I had done this sooner.

I really appreciate it.

Re: Generic type passed into method question

OriginalGriff10-Dec-17 1:49

OriginalGriff

10-Dec-17 1:49

You're welcome!

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Re: Generic type passed into method question

Eddy Vluggen10-Dec-17 3:03

Eddy Vluggen

10-Dec-17 3:03