C# Discussion Boards - CodeProject

Re: Seperate conversion functions or 1 overloaded function?

10-Oct-10 14:14

What about shoe sizes? Big Grin | :-D

Eddy Vluggen10-Oct-10 20:37

Eddy Vluggen

10-Oct-10 20:37

PIEBALDconsult wrote:
What about shoe sizes?

Never considered those, but you're right Laugh | :laugh:

I are Troll Suspicious | :suss:

Retrieving a DataTable from a Collection by name

boreland10-Oct-10 1:02

boreland

10-Oct-10 1:02

Is there a direct way to access a datatable in a collection directly by its name?

Currently, the only way I know how access a datatable is by using a foreach statement to find the table I wish to update/modify:

DataTableCollection tables = collection.Tables;<br />
                 <br />
                foreach (DataTable tbl in tables)<br />
                {<br />
                    string name = tbl.TableName;<br />
                    <br />
                    if (name == "name")<br />
                    {<br />
                        //Update datatable with new row<br />
                        DataRow myNewRow;<br />
                        myNewRow = tbl.NewRow();<br />
<br />
                        code.....<br />
<br />
                        tbl.Rows.Add(myNewRow);   <br />
                         <br />
                    }<br />
}

Thanks for any help

Re: Retrieving a DataTable from a Collection by name

OriginalGriff10-Oct-10 1:12

Re: Retrieving a DataTable from a Collection by name

10-Oct-10 1:12

Umm... perhaps DataTableCollection.Item[^]

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

boreland10-Oct-10 1:20

boreland

10-Oct-10 1:20

Thanks for the answer. I've not used datatable collections before and was spinning my wheels. So I can replace the foreach loop with:

DataTable table = tables["name"];

Re: Retrieving a DataTable from a Collection by name

OriginalGriff10-Oct-10 1:23

Re: Retrieving a DataTable from a Collection by name

10-Oct-10 1:23

Yep. Should work for all collections!

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

MasttsaM13-Oct-10 21:27

MasttsaM

13-Oct-10 21:27

ds = DB.FillDataSet(cmd, "StRecord");
GridView1.DataSource = ds.Tables[0];
GridView1.DataBind();
foreach (DataColumn col in ds.Tables[0].Columns )
{

}

From: <ahref="http: www.programlive.tk"="">http://www.programlive.tk

Controlling a Parallel Port

TowerTurtle9-Oct-10 11:30

TowerTurtle

9-Oct-10 11:30

I have written a program in C# using inpout32.dll which, when you press a button, it sets all the data pins on the paralell port to high by setting the address as 888 and the decimal value 255 to that address. I have heard that when a pin on the port is a high, it is outputting a voltage of 5v, but it shows about 1.5v constantly, not changing, while none of the other data ports do anything. I have a feeling this is not working because I either have the wrong address, or I am setting the wrong value.

In my BIOS, it says that the address is 378h, which I know if 888 in decimal, which is why I am setting it as the address. I also have the mode set to EPP. Can somebody tell me what I am doing wrong?

Re: Controlling a Parallel Port

PIEBALDconsult9-Oct-10 14:52

9-Oct-10 14:52

I don't know. I've used that in one small app. My code is:

        [
            System.Runtime.InteropServices.DllImportAttribute 
            ( 
                "INPOUT32" 
            , 
                SetLastError=true 
            , 
                EntryPoint="Out32" 
            )
        ]
        private static extern void
        API_Out32
        (
            System.Int32 Port
        ,
            System.Int32 Data
        ) ;
        
        public static void
        WriteToPort
        (
            System.UInt16 Port
        ,
            System.Byte   Data
        )
        {
            API_Out32
            (
                Port
            ,
                Data
            ) ;
            
            return ;
        }

PIEBALD.Lib.LibApi.WriteToPort ( 0x378 , (byte) this.tvStati.Tag ) ;

Highscore

SRJ929-Oct-10 9:35

SRJ92

9-Oct-10 9:35

hi, i want to store 2 strings which are named "player" and "score" ,
how do i create a table for this and i want to know how to display this information ...

thanks for all your help

PIEBALDconsult9-Oct-10 9:40

9-Oct-10 9:40

XML

<Game>
  <Players>
    <Player Name="Joshua" Score="42" />
  </Players>
</Game>

How you display it is up to you.

dan!sh 9-Oct-10 10:32

dan!sh

9-Oct-10 10:32

Won't that give InsaneDataException at name?

PIEBALDconsult9-Oct-10 15:53

9-Oct-10 15:53

What? I said Joshua, not HAL.

Abhinav S9-Oct-10 17:44

Abhinav S

9-Oct-10 17:44

You need to get some books on databases and start reading...

The funniest thing about this particular signature is that by the time you realise it doesn't say anything it's too late to stop reading it.

My latest tip/trick

Visit the Hindi forum here.

Marshalling a structure to contain an array whose length is an earlier struct member?

Richard MacCutchan9-Oct-10 21:49

Richard MacCutchan

9-Oct-10 21:49

Store them where? In memory, database, text file, ...
Display them how? On screen, console, printer, ...

Try and describe your problem in clearer terms.

Just say 'NO' to evaluated arguments for diadic functions! Ash

o m n i9-Oct-10 9:33

o m n i

9-Oct-10 9:33

For loading a file that was originally written by an application written in C++, I have been declaring each part of the file as a struct, and converting the data into a struct using this function:

public static TStruct GetStruct<TStruct>(byte[] data,Type t)
      where TStruct : new()
    {
      int structSize = Marshal.SizeOf(typeof(TStruct));
      TStruct outstruct = new TStruct();
      GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
      outstruct = (TStruct)Marshal.PtrToStructure(handle.AddrOfPinnedObject(),t);
      handle.Free();
      return outstruct;
    }

This works fine for structs that do not contain arrays or that contain only arrays that can be defined using fixed (eg fixed int someVariable[10]; works fine) ,but I run into a problem when I want to do this to a struct such as:

struct Foobar
{
int count;
customStructType someStruct[count];
}

I've tried using [MarshalAs(UnmanagedType.<tried all these>, <parameters specified type takes here>)] but it either requires me to specify a fixed number upfront or causes my GetStruct method to give me an error that it "could not meaningfully obtain the size of the struct". LPArray allowed me to specify a particular element in the struct that acts as the number of elements in the array but that gave me the aforementioned lack of meaningful size error. Is there any way to make this work?

Re: Marshalling a structure to contain an array whose length is an earlier struct member?

OriginalGriff10-Oct-10 0:19

An attempt was made to access the socket in a way forbidden by its access permissions

10-Oct-10 0:19

Nasty one. AFAIK .NET does not allow any direct coding that will create a structure whose length is not fixed at compile time - and I can understand why not.
I haven't tried it, but this[^] appears to address the problem. In a suitably nasty way, of course... Laugh | :laugh:

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

ars.029-Oct-10 8:02

ars.02

9-Oct-10 8:02

Hi everyone..

I am getting the above error in one of the application on this portal.

The application is:
http://www.codeproject.com/KB/IP/CSNetworkSniffer.aspx?msg=3625563#xx3625563xx

I am really new to socket programming so i need your help

Thank you and any help would be appreciated

Re: An attempt was made to access the socket in a way forbidden by its access permissions

Richard MacCutchan9-Oct-10 21:47

Richard MacCutchan

9-Oct-10 21:47

Try posting your question in the forum at the end of the article, and then the author should get notified.

Just say 'NO' to evaluated arguments for diadic functions! Ash

Re: An attempt was made to access the socket in a way forbidden by its access permissions

Dave Kreskowiak10-Oct-10 3:19

Dave Kreskowiak

10-Oct-10 3:19

It uses raw sockets to sniff TCP/IP, which cannot be done in Windows XP SP2 and above for security reasons. If you want to run this code, you'll need to do it on Windows Server 2003 and above.

From MSDN on Raw Socket limitations:

On Windows 7, Windows Server 2008 R2, Windows Vista, and Windows XP with Service Pack 2 (SP2), the ability to send traffic over raw sockets has been restricted in several ways:

•TCP data cannot be sent over raw sockets.
•UDP datagrams with an invalid source address cannot be sent over raw sockets. The IP source address for any outgoing UDP datagram must exist on a network interface or the datagram is dropped. This change was made to limit the ability of malicious code to create distributed denial-of-service attacks and limits the ability to send spoofed packets (TCP/IP packets with a forged source IP address).
•A call to the bind function with a raw socket is not allowed.

These above restrictions do not apply to Windows Server 2008 , Windows Server 2003, or to versions of the operating system earlier than Windows XP with SP2.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

A question on wcf and composite objects

Michael Eber9-Oct-10 7:20

Michael Eber

9-Oct-10 7:20

This is my scenario: I have a huge database and I'm building numerous services to access the data.
Each service exposes a unique set of data and services to the consumer.

So for an object such as Company our internal service needs the raw address in the composite. However our portal service need fully enumerated Address info in the composite.

I wanted to avoid having a massive object with various composite addon's that don't apply to a given object but I'm running into difficulties.

First I decided that each composite builder class will be in a namespace deeper than the data namespace. So instead of myApp.Data it would be myApp.Data.Mainservice and myApp.Data.Portalservice for the composite objects.

My next step was to inherit Company, add a constructure that takes Company as input to populate internal fields, and add the DataMember for each Composite that is needed. Works great but I get a runtime error that I cannot inherit an object that is not marked as Serializable or DataContract.

Initially I just added a public partial class Customer and added the DataContract attribute, but that does not expose the DataMembers inside of the object.

I also cannot use the partial class definition as I need to be inside the namespace of the Customer object which puts me back into the same problem of having an accumulation of composite objects.

For those who need pictures here is the code I want to implement:

namespace Company.Data.InternalServices
{
     [DataContract]
     public sealed class CompositeLocation : Company.Data.Location
     {

           [DataMember]
           public Address LocationAddress{get;set;}

      }


[ServiceContract]
public class InternalContract:IInternalContract
{
     [OperationContract]
     public CompositeLocation GetLocation( Guid LocationIdentity );
}

}

namespace Company.Data.Portal
{
      [DataContract]
      public sealed class CompositeLocation:Location
      {
            [DataMember]
             public EnumeratedAddress{get;set;}
       }

      [ServiceContract]
      public class PortalContract:IPortalContract
      {
           [OperationContract]
           public CompositeLocation GetLocation(Guid LocationIdentity);
       }
 }

When no method returns a Location, WCF drops the DataContract for Location. I want to force it to keep Location as a data contract!!! Cool | :cool:

which way better for activation?

Jassim Rahma9-Oct-10 5:21

Jassim Rahma

9-Oct-10 5:21

I have a software which requires activation. I am going to save the user registration data on my sql server database on my host (online) via the WinForm registration form.

DO you recommended to do a normal sqlConection from the WinForm to the sql server online to syore the data?

or it's better to develop a web service for that?

what do you think?

Re: which way better for activation?

DaveAuld9-Oct-10 6:04

DaveAuld

9-Oct-10 6:04

Web Service

You should never expose the SQL server to public access outwith a private network unless you really really really must....

Dave
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Re: which way better for activation?

OriginalGriff9-Oct-10 6:15