Re: Smart device authentification problem - C# Discussion Boards

Re: Smart device authentification problem

William Winner13-Apr-10 13:31

13-Apr-10 13:31

God...you've totally mixed ideas from your last thread without actually finishing one.

You created dat, but you never actually filled it with any values. You need to use the Select statement to fill the datatable. The way you have it, nothing will ever be in the datatable.

As Luc has said, dat.Tables["Connexion"].Select will never return a null value. it will return an array of DataRow...in your case with an upper bound of -1.

First, read up on ADO.NET. Then, use a SELECT statement to fill a datatable using the "WHERE login = @login...".

Then, you just check the datatable Rows.Count property to see if it has rows.

And, again, like they've said, don't use "like" in password authentication. "Like %a%" will return a high percentage of words (any word with 'a' in it).

ADO.NET[^] (it's in English...hopefully your English is good enough to get through it...otherwise, find a book in French on ADO.NET)

Re: Smart device authentification problem

Tunisien8614-Apr-10 2:32

Tunisien86

14-Apr-10 2:32

Hi,
I tried like this but still not working:

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlServerCe;

namespace ModeDifféré
{
    public partial class Connexion : Form
    {
        public Connexion()
        {
            InitializeComponent();
        }

        private void Connexion_load(object sender, EventArgs e)
        {
            createconnexion();
        }

        private void createconnexion()
        {
            /*string chbd= Environment. + "\\BaseGmaoLocale.sdf";
            //string chcon= "Data source=\'[0]'\ BaseGmaoLocale.sdf;";
            SqlCeConnection sqlceconn= new SqlCeConnection(chcon);
            sqlceconn.Open();*/
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string chcon = null;
            SqlCeCommand command;
            SqlCeDataAdapter adapter = new SqlCeDataAdapter();
            adapter.TableMappings.Add("Table", "Connexion");
            DataSet ds = new DataSet();
            string sql = null;
            string login,MotPass;
            sql = "Select login from Connexion where login=@login and MotPass=@MotPass ";
            string chcc= "BaseGmaoLocale.sdf;";
            SqlCeConnection sqlceconn= new SqlCeConnection(chcc);
            sqlceconn.Open();
            try
            {
                  sqlceconn.Open();
                command = new SqlCeCommand(sql, sqlceconn);
                adapter.SelectCommand = command;
                adapter.Fill(ds, "SQL Temp Table");
                adapter.Dispose();
                command.Dispose();
                sqlceconn.Close();

                MessageBox.Show("Number of row(s) - " + ds.Tables[0].Rows.Count);
            }
            catch (Exception ex)
            {
                MessageBox.Show("Can not open connection ! ");
            }
            if (ds.Tables[0].Rows.Count != 0)
            {
                MessageBox.Show("Authentification réussie");
                MenuP m = new MenuP();
                m.Show();
            }
            else
            {
                MessageBox.Show("Login ou mot de passe incorrect veuillez réessayer");
            }
        }
    }
}

4 notifications appears:

Warning	1	The variable 'chcon' is assigned but its value is never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs	
Warning	2	The variable 'login' is declared but never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs	
Warning	3	The variable 'MotPass' is declared but never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs	
Warning	4	The variable 'ex' is declared but never used	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs

When running it tells me there are an error in the connexion string chcc
Can u help me
Thanks

Re: Smart device authentification problem

William Winner14-Apr-10 6:56

William Winner

14-Apr-10 6:56

You're still not understanding the basic concepts. Have a look at the example on this page: SqlCeDataAdapter Class[^]

Here are the steps you need to do...
1. Create the Connection
2. Create the command and sql string that will extract the data
3. Add the parameter values to the command
4. Create the adapter using the command
5. Fill the dataset

The errors you get are self-explanatory...you created variables that you never assign anything to or use in any way.

You also created a sql string with parameters in it, but then never filled the parameters, so you're never going to return what you want.

With your code...you would want to follow the steps:

//Create the connection
string chcc= "Data Source = BaseGmaoLocale.sdf;";
SqlCeConnection sqlceconn= new SqlCeConnection(chcc);

//Create the command
SqlCeCommand command = sqlceconn.CreateCommand();
command.CommandText = "Select login from Connexion where login=@login and MotPass=@MotPass ";

//Add the parameters
string s1; //store the login name here YOU MUST FILL THIS IN
SqlCeParameter login = new SqlCeParameter("@login", SqlDbType.NVarChar);
login.value = s1;

string s2; //store the password here YOU MUST FILL THIS IN
SqlCeParameter MotPass = new SqlCeParameter("@MotPass", SqlDbType.NVarChar);
MotPass.value = s2;

command.Parameters.Add(login);
command.Parameters.Add(MotPass);

//Create the adapter
SqlCeDataAdapter adapter = new SqlCeDataAdapter(command);

//Create and fill the dataset
DataSet ds = new DataSet();

try
{
   adapter.Fill(ds, "SQL Temp Table");
}
catch (Exception ex)
{
   MessageBox.Show(ex.Message);
}
if ((ds.Tables.Count > 0) && (ds.Tables["SQL Temp Table"] != null))
    MessageBox.Show("Number of row(s) - " + ds.Tables["SQL Temp Table"].Rows.Count);

adapter.Dispose();
sqlceconn.Dispose();
command.Dispose();

if that doesn't work, tell me what the exception message is specifically...and don't change anything that I've written...try it as is filling in the login and password information.

And you only need to put the specific line that could throw an error in the Try/Catch block. In this case, nothing should throw an error until the adapter.Fill call.

Re: Smart device authentification problem

William Winner14-Apr-10 7:12

William Winner

14-Apr-10 7:12

To be fair...you've gotten some conflicting...and some bad information.

One of which did come from me...which I explained the mistake I made (using parens instead of brackets to get at an item in an array)

You had one person telling you to use wildcards...which no programmer in their right mind would do when dealing with authentication...it's either all or nothing.

You had someone tell you to use:

string req = "SELECT * FROM Connexion WHERE Login = @login AND MotPasse = @pass";
SqlCeCommand cmd = new SqlCeCommand(req, cnx);
SqlCeParameter login = new SqlCeParameter("login", s1);
cmd.Parameters.Add(login);
SqlCeParameter pass = new SqlCeParameter("pass", s2);
cmd.Parameters.Add(pass);

which won't work because he used "@login" and "@pass" as his parameter names but then didn't include the "@" when defining the parameters which is required.

You had someone tell you to use: int count = cmd.ExecuteScalar();. That's not always going to work, and it doesn't return a count of anything. It just returns the value in the first column of the first row. So if your first column is a string, this should throw an error.

But, he was right in saying that you could do it that way and see if it returned an object or a null value. You could say

string req = "SELECT * FROM Connexion WHERE Login = @login AND MotPasse = @pass";
SqlCeCommand cmd = new SqlCeCommand(req, cnx);
SqlCeParameter login = new SqlCeParameter("@login", s1);
cmd.Parameters.Add(login);
SqlCeParameter pass = new SqlCeParameter("@pass", s2);
cmd.Parameters.Add(pass);

object value = cmd.ExecuteScalar();
if (value != DbNull.Value)
{
   MessageBox.Show("Authentification réussie");
}

Re: Smart device authentification problem

Tunisien8614-Apr-10 10:23

Tunisien86

14-Apr-10 10:23

Hi William,
You propose to me 2 solutions:
*First Solution

private void button1_Click(object sender, EventArgs e)
        {
            /*string req = "select Login, MotPasse from Connexion";
            DataTable tab = new DataTable();
            SqlCeCommand com = new SqlCeCommand(req, sqlceconn);
            SqlCeDataAdapter ada = new SqlCeDataAdapter(com);
             ada.Fill(tab);*/
            string s1 = textBox1.Text;
            string s2 = textBox2.Text;
            SqlCeConnection cnx = new SqlCeConnection();
            string wCS = String.Format("DATA SOURCE =BaseGmaoLocale.sdf" );
            cnx.ConnectionString = wCS;
            string req = "SELECT * FROM Connexion WHERE Login = @login AND MotPasse = @pass";
            SqlCeCommand cmd = new SqlCeCommand(req, cnx);
            SqlCeParameter login = new SqlCeParameter("login", s1);
            cmd.Parameters.Add(login);
            SqlCeParameter pass = new SqlCeParameter("pass", s2);
            cmd.Parameters.Add(pass);
            object value = cmd.ExecuteScalar();
            if (value != DbNull.Value)
            {
                MessageBox.Show("Authentification réussie");
            }
            else
            {
                MessageBox.Show("Login ou mot de passe incorrect veuillez réessayer");
            }
        }
    }
}

This solution has an error in Dbnul

Error	1	The name 'DbNull' does not exist in the current context	C:\Users\Admin\Documents\Visual Studio 2008\Projects\GMAOMobile\ModeDifféré\Connexion.cs

I added the directory using System.Runtime and the class

[SerializableAttribute]
        [ComVisibleAttribute(true)]
        public sealed class DBNull :ISeriasable,IConvertible
        {
        }

but this solution doesn't work
*Second Solution:

//Create the connection
string chcc= "Data Source = BaseGmaoLocale.sdf;";
SqlCeConnection sqlceconn= new SqlCeConnection(chcc);

//Create the command
SqlCeCommand command = sqlceconn.CreateCommand();
command.CommandText = "Select login from Connexion where login=@login and MotPass=@MotPass ";

//Add the parameters
string s1; //store the login name here YOU MUST FILL THIS IN
SqlCeParameter login = new SqlCeParameter("@login", SqlDbType.NVarChar);
login.value = s1;

string s2; //store the password here YOU MUST FILL THIS IN
SqlCeParameter MotPass = new SqlCeParameter("@MotPass", SqlDbType.NVarChar);
MotPass.value = s2;

command.Parameters.Add(login);
command.Parameters.Add(MotPass);

//Create the adapter
SqlCeDataAdapter adapter = new SqlCeDataAdapter(command);

//Create and fill the dataset
DataSet ds = new DataSet();

try
{
   adapter.Fill(ds, "SQL Temp Table");
}
catch (Exception ex)
{
   MessageBox.Show(ex.Message);
}
if ((ds.Tables.Count > 0)&&(ds.Tables["SQL Temp Table"] != null))
    MessageBox.Show("Number of row(s) - " + ds.Tables["SQL Temp Table"].Rows.Count);

adapter.Dispose();
sqlceconn.Dispose();
command.Dispose();

This solution tells me that the path of my database is not found.Also,where can i add this statement to show me the message Box :

 if (ds.Tables["SQL Temp Table"].Rows.Count!=0)
{
   MessageBox.Show("Authentification réussie");
}
else
{
MessageBox.Show("Login ou mot de passe incorrect veuillez réessayer");
}

what can i do and what solution do i follow?
Thanks

Re: Smart device authentification problem

William Winner14-Apr-10 10:48

William Winner

14-Apr-10 10:48

You're still not getting the basics.

When you use a parameter..as in SqlCeParameter login = new SqlCeParameter("login", s1);, you have to use the name exactly as you typed it in the SQL...in this case "@login".

As far as DbNull not existing, I don't know what to tell you because it's a class within the System namespace. Make sure you've include using System; in your header. If you didn't, you can include it, or use System.DbNull. But the first code still won't work because you have the parameters wrong.

As far as the second code, you didn't provide values for s1 and s2

You need to change

string s1; //store the login name here YOU MUST FILL THIS IN<br />

to
string s1 = textBox1.Text;

and do the same for s2. If you can't understand that concept, then this project is way beyond your skills. You have to provide a value to a variable.

And I'm just curious, but when you run the first solution, insert a breakpoint at line object value = cmd.ExecuteScalar();. Run the code and tell me what value is.

And I'm sorry, but if you can't tell where to insert that line of code, then you need to pay someone to do this for you, because that's basic coding. If you don't understand the code that we've written, then you shouldn't be doing this.

Re: Smart device authentification problem

Tunisien8614-Apr-10 13:01

Tunisien86

14-Apr-10 13:01

Hi William,
It seems difficult for me because it is the first time I develop a Csharp smart device application.

For the second code:the problem still in the database path.Althought i follow this link,http://www.connectionstrings.com/sql-server-2005-ce[^],I change my connectionstring by: string wCS = String.Format("Data Source=C:\\Users\\Admin\\Documents\\Visual Studio 2008\\Projects\\GMAOMobile\\ModeDifféréBaseGmaoLocal.sdf;Persist Security Info=False;");it still the same sql exception

For the first code,the same exception of the database appears.
Thank u if u help me more
Smile | :)

Re: Smart device authentification problem

Tunisien8619-Apr-10 23:00

Tunisien86

19-Apr-10 23:00

Hi,
Thank u a lot,I found the solution finally.This is the code

private void button1_Click(object sender, EventArgs e)
        {

            /*string req = "select Login, MotPasse from Connexion";
            DataTable tab = new DataTable();
            SqlCeCommand com = new SqlCeCommand(req, sqlceconn);
            SqlCeDataAdapter ada = new SqlCeDataAdapter(com);
            ada.Fill(tab);*/
            //Create the connection
            string wCS = @"Data Source =\Storage Card\ModeDifféré\BaseGmaoLocale.sdf;";
            SqlCeConnection sqlceconn = new SqlCeConnection(wCS);

            //Create the command
            SqlCeCommand command = sqlceconn.CreateCommand();
            command.CommandText = "Select login from Connexion where Login=@Login and MotPasse=@MotPasse ";

            //Add the parameters
            string s1=textBox1.Text; //store the login name here YOU MUST FILL THIS IN
            SqlCeParameter Login = new SqlCeParameter("@Login", SqlDbType.NVarChar);
            Login.Value = s1;

            string s2=textBox2.Text; //store the password here YOU MUST FILL THIS IN
            SqlCeParameter MotPasse = new SqlCeParameter("@MotPasse", SqlDbType.NVarChar);
            MotPasse.Value = s2;

            command.Parameters.Add(Login);
            command.Parameters.Add(MotPasse);

            //Create the adapter
            SqlCeDataAdapter adapter = new SqlCeDataAdapter(command);

            //Create and fill the dataset
            DataSet ds = new DataSet();

            try
            {
                adapter.Fill(ds, "SQL Temp Table");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            if ((ds.Tables.Count > 0) && (ds.Tables["SQL Temp Table"] != null))
            {MessageBox.Show("Number of row(s) - " + ds.Tables["SQL Temp Table"].Rows.Count);
                if(ds.Tables["SQL Temp Table"].Rows.Count>0)
                { MessageBox.Show("Authentification réussie");
                MenuP m = new MenuP();
                m.Show();}
                else MessageBox.Show("Login ou mot de passe incorrect veuillez réessayer");}
            adapter.Dispose();
            sqlceconn.Dispose();
            command.Dispose();



        }

Thanks a lot for all u contribution

Writing Assembly Attributes Programmatically

Nadia Monalisa13-Apr-10 10:26

Nadia Monalisa

13-Apr-10 10:26

Hello,

I have assembly attributes like this:

[assembly: InternalsVisibleTo("UI Test")]
[assembly: AssemblyCopyright("Copyright © 2009")]

in my AssemblyInfo.cs file. But, now, I want to set the values programmatically from my code. Is it possible ? If so, can you please give me a snippet to do that ?

Re: Writing Assembly Attributes Programmatically

Martin Jarvis13-Apr-10 10:32

Martin Jarvis

13-Apr-10 10:32

Not for the executing assembly, once the assemblies compiled these attributes are 'baked' in. However, you may be able to do it for a dynamically generated assembly using the Reflection Emit functionality.

Re: Writing Assembly Attributes Programmatically

Paw Jershauge13-Apr-10 10:41

Paw Jershauge

13-Apr-10 10:41

I dont get, why would you like to do this runtime???

With great code, comes great complexity, so keep it simple stupid... $Shucks | :-\$ $Shucks | :-\$

Re: Writing Assembly Attributes Programmatically

Nadia Monalisa13-Apr-10 11:00

Nadia Monalisa

13-Apr-10 11:00

Hi Paw, thanks for reply.

Ok, I have the assembly attribute

[assembly: InternalsVisibleTo("UI Test")]

And I want it applicable only when I do debugging and testing. I dont want to make internals visible to some assembly in my production build. Now, Yes, I can comment this line everytime I make a RELEASE build and comment out when I do debugging, but it is not easy to maintain. Many times I can forget to comment this line and ship the release build with this attribute. Now, if I know how I can do it programmatically, then, I will use

#if (DEBUG)
...
[assembly: InternalsVisibleTo("UI Test")]

#end if

So, I dont have to remember to comment this line.

Thats why I need the snippet for doing so. Can you give me any idea for doing this task in some other way ?

Thanks again.

Re: Writing Assembly Attributes Programmatically

PIEBALDconsult13-Apr-10 11:17

PIEBALDconsult

13-Apr-10 11:17

Does # if DEBUG not work for that?

Maybe have two versions of AssemblyInfo.cs?

Re: Writing Assembly Attributes Programmatically

Nadia Monalisa13-Apr-10 11:46

Nadia Monalisa

13-Apr-10 11:46

Owee... yes, it is working. I could not think that it will work, I thought I cannot write any C# code in AssemblyInfo.cs file. So, I did not dare to try. Now it see it works Smile | :)

thanks.

Re: Writing Assembly Attributes Programmatically

Luc Pattyn13-Apr-10 13:16

Luc Pattyn

13-Apr-10 13:16

There isn't anything special about AssemblyInfo.cs
The file extension is .cs which stands for C-sharp.
and you can move all of its content to another C# file, e.g. Program.cs

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

Prolific encyclopedia fixture proof-reader browser patron addict?
We all depend on the beast below.

Re: Writing Assembly Attributes Programmatically

PIEBALDconsult13-Apr-10 13:36

PIEBALDconsult

13-Apr-10 13:36

Or simply delete it.

Re: Writing Assembly Attributes Programmatically

Luc Pattyn13-Apr-10 13:41

Luc Pattyn

13-Apr-10 13:41

yeah, however that ruins the nice little About Box Visual Studio is keen to provide.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

Prolific encyclopedia fixture proof-reader browser patron addict?
We all depend on the beast below.

Re: Writing Assembly Attributes Programmatically

PIEBALDconsult13-Apr-10 13:47

PIEBALDconsult

13-Apr-10 13:47

I've tried that, but I prefer a simple MessageBox.

Print images with the correct size

Eagle3213-Apr-10 9:33

Eagle32

13-Apr-10 9:33

Hi,

I am currently working on printing an image from my picturebox but i am finding difficulties regarding this.

For example, I have a large image of 1024 x 768. How would i go about working out the correct size regarding the width and height
so when the image is printed, it is printed with the original width and height i.e 1024 x 768 in this example.

At the moment, i am having trouble doing this. If i do the following the image takes up all of the page(i know why) but the original
image doesnt even take up the whole page. I am using A4 piece of paper.

Here is the code:

//the width and height I will be using
 float destHeight = bitmap.Height /bitmap.VerticalResolution * 90;
 float destWidth = bitmap.Width / bitmap.HorizontalResolution * 90;


//Boundary for printable area
float highestHeight = destHeight / e.MarginBounds.Height;
float highestWidth = destWidth / e.MarginBounds.Width;

I would greatly appreciate if somebody could kindly assist me with this problem.

Thanks & Regards,

Re: Print images with the correct size

Alan Balkany14-Apr-10 3:57

Alan Balkany

14-Apr-10 3:57

My guess: The vertical/horizontal resolution of the bitmap is not the same as the printer's resolution, so the destHeight/destWidth are getting incorrect values. You need to use the printer's resolution in your calculations.

Re: Print images with the correct size

Eagle3214-Apr-10 11:55

Eagle32

14-Apr-10 11:55

Hi,

Thanks for replying. How would i go about doing this?

Would this work?

<br />
PrintDocument document = new PrintDocument();<br />
<br />
document.PrinterSettings.DefaultPageSettings.PrinterResolution.X = 300;<br />
document.PrinterSettings.DefaultPageSettings.PrinterResolution.Y = 300;<br />
<br />

Thanks,

Re: Print images with the correct size

Alan Balkany15-Apr-10 2:56

Alan Balkany

15-Apr-10 2:56

The printer's resolution would probably be mentioned in the owner's manual. If not, look on the manufacturer's web site. If it's not there, send their support department an email.

Running a BackgroundWorker in a Single Threaded Apartment

William Winner13-Apr-10 9:09

William Winner

13-Apr-10 9:09

So, I have been working on a project to allow me to query an OLAP data cube from within another program. I built a form that I use to connect to the cube, pull out the information for the user to select from, and then it creates the query.

It works great as a stand-alone application. The info is loaded using a BackgroundWorker and updates the UI as the loading completes certain levels (it can take up to a minute to load the entire cube's dimensions and lower levels.

My problem is that I built it to work in a program, that I now discover runs in a Single Threaded Apartment. Within that environment, the BackgroundWorker.DoWork event never gets called. I did a little test using the Threading.Thread model and that seems to work the way I would expect.

My question is, does anyone know why the BackgroundWorker wouldn't work within an STA and is there a way around it without rewriting my code to switch from a BackgroundWorker to the Threading.Thread model?

Re: Running a BackgroundWorker in a Single Threaded Apartment

Luc Pattyn13-Apr-10 11:08

Luc Pattyn

13-Apr-10 11:08

Hi William,

a lot of my programs are STA and use BGW successfully. The problem probably is with what you have inside your DoWork method; AFAIK STA will prevent multiple threads (BGW or other) to concurrently enter a COM object, so if one thread is executing code of such COM object, another thread will have to wait.

Smile | :)

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Prolific encyclopedia fixture proof-reader browser patron addict?
We all depend on the beast below.

Re: Running a BackgroundWorker in a Single Threaded Apartment

William Winner13-Apr-10 11:21

William Winner

13-Apr-10 11:21

My problem is that the BackgroundWorker DoWork event is never even raised.

I have:

LoadCubeInBackground = New BackgroundWorker();
LoadCubeInBackground.WorkerReportsProgress = True;
LoadCubeInBackground.WorkerSupportsCancellation = True;

LoadCubeInBackground.DoWork += new DoWorkEventHandler(LoadCube);
LoadCubeInBackground.ProgressChanged += new ProgressChangedEventHandler(LoadCubeInBackground_ProgressChanged);

LoadCubeInBackground.RunWorkerAsync(_connectionString);

But, the first line of my LoadCube function never gets hit.

Right now...because converting it to the Threading.Thread model just doesn't seem like it's going to be easy, I'm looking at just starting the form as a process and having it output a string when it finishes. The whole point of the form is to end up with MDX queries, so I can just join each query into a single string, and then split it in the other program...

There are a few arguments to pass in, but they're all strings, so I can handle it with Environment.GetCommandLineArgs.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.