Find user & password in Access DB. - C# Discussion Boards

eggie56-Jul-05 10:54

6-Jul-05 10:54

Off the top of my head...

You can set up a client/server application on the two machines respectively, and then send a certain message from the client program to the waiting server and depending on the message received have the server execute that particular command, whether it be shut down, log off, lock etc.

On the server to log off, shut down and junk, look into the windows api and pinvoke the needed functions to preform those operations. Off the top of my head to shut down is ExitWindowsEx, just poke around it shouldn't be hard to find.

But, once you log out remotely, you won't be able to log back in remotely. I don't think...

/\ |_ E X E GG

Re: Log off/Lock a client machine

eternalsoul6-Jul-05 20:01

eternalsoul

6-Jul-05 20:01

right thanks.. any one has an actual sample of a code of a form with a lock/unlock button on the client where i can log off or lock the client. Once i know how to do that locally, I should be able to do it remotely. thanks

Feedback from a form

Carl-Johan Larsson6-Jul-05 9:55

Carl-Johan Larsson

6-Jul-05 9:55

Hi,
I have two Forms (A and B). When Form A is active I open Form B. I then want to run some code automatically in Form A when I close Form B. How do I do that?

Thanks,

Carl-Johan Larsson

Re: Feedback from a form

Christian Graus6-Jul-05 11:29

Christian Graus

6-Jul-05 11:29

I assume FormB is not modal - that is, you show it so that it floats but you can still use FormA ( you call Show instead of ShowDialog ). You need to create a function in FormA that looks like this:

private static void dlg_Closed(object sender, EventArgs e)
{

}

then before you show FormB in FormA, you do this ( assuming dlg is the name of your FormB class instance:

dlg.Closed += new EventHandler(dlg_Closed);

There is also a Closing event, which get's called BEFORE the form closes. Now add your code to the method you added to FormA.

Christian Graus - Microsoft MVP - C++

Re: Feedback from a form

Carl-Johan Larsson6-Jul-05 18:48

Carl-Johan Larsson

6-Jul-05 18:48

Did the trick, Thanks Carl-Johan Larsson

PowerCollections 1.0 is released

Kevin McFarlane6-Jul-05 9:53

Kevin McFarlane

6-Jul-05 9:53

http://www.wintellect.com/weblogs/default.aspx?GroupID=2[^]

Power Collections is a set of classes and methods that add new generic collection types and algorithms to the .NET Framework 2.0.

Kevin

Re: PowerCollections 1.0 is released

Judah Gabriel Himango6-Jul-05 10:57

Judah Gabriel Himango

6-Jul-05 10:57

Awesome! Thanks for the info. Looking forward to the Wintellect PowerThreading library I've heard to be in the works...

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Homosexuality in Christianity
Judah Himango

Find user & password in Access DB.

sea#6-Jul-05 9:30

sea#

6-Jul-05 9:30

I'm writing a small app, and I have to prepare a form which will authenticate users. This is the code I wrote. The problem is I get exception in the marked line : "no value given for for on or more required parameters"
What is wrong with it?
Table name is users.
Column name is UserName

<br />
public void userExists(string username)<br />
		{<br />
		try<br />
			{//SQL statements<br />
			string sqlFinduser = "SELECT COUNT(UserName) AS UserNameExists " +<br />
					"FROM users " +<br />
					"WHERE (UserName=" + username + ")";<br />
<br />
				//Command object<br />
				OleDbCommand cmdFindsqlFinduser = new OleDbCommand();<br />
			<br />
				cmdFindsqlFinduser.Connection = cnSurvey;<br />
				cmdFindsqlFinduser.CommandType = CommandType.Text;<br />
				cmdFindsqlFinduser.CommandText = sqlFinduser;<br />
<br />
				//Connect<br />
				cnSurvey.Open();<br />
<br />
				//Execute command<br />
int count = int.Parse(cmdFindsqlFinduser.ExecuteScalar().ToString()); <br />
			//error is right here                      <br />
<br />
				bool exists = count != 0 ? true : false;<br />
			<br />
			//Disconnect<br />
			cnSurvey.Close();<br />
<br />
			//Return result<br />
	//		return exists;<br />
				}<br />
			catch(Exception ex)<br />
			{<br />
				MessageBox.Show(ex.Message);<br />
			}<br />
		<br />
		}<br />
<br />

TIA,

Ronen

Re: Find user & password in Access DB.

Guffa6-Jul-05 11:17

Guffa

6-Jul-05 11:17

That means that you have one or more names in your query that the database does not regognise.

You have forgotten the apostrophes around the value for username. The database will try to interpret the username as being an identifier, not a string.

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Re: Find user & password in Access DB.

malharone6-Jul-05 13:13

malharone

6-Jul-05 13:13

How about changing
(UserName=" + username + ")"
to
(UserName='" + username + "')"

assume: username = "abc"
Current code: (UserName = abc)
Fixed code: (UserName = 'abc')

Re: Find user & password in Access DB.

Matt Gerrans7-Jul-05 10:57

Matt Gerrans

7-Jul-05 10:57

How about using Parameters instead of duct-taping together your SQL statements?
Visual Basic and Visual C# Concepts - Parameters in Data-Adapter Commands[^]

Doesn't everyone know about the security holes in the duct-tape approach, yet?

By the way, are you storing the password in the db in plain text?

Matt Gerrans

Please help - COM Interop

metal_rob6-Jul-05 8:44

metal_rob

6-Jul-05 8:44

Hey everyone, a quick thanks for taking a look at this...

Basically, my problem is this... I have a "Core" library which contains a "Manager" component, and I want to use this component in C#. This component is written in C++, and here is the IDL file defining its type library.

<br />
import "unknwn.idl";<br />
<br />
[<br />
object,<br />
uuid(822A2EDE-09F1-45b8-B80E-A32F21415677),<br />
helpstring("Interface used by the Manager")<br />
]<br />
<br />
interface IManager : IUnknown<br />
{<br />
	HRESULT GetAppName([out, size_is(, *pcMax)] char **ppAppName,<br />
						   [out] long *pcMax);<br />
<br />
	HRESULT	SetStatus([in] long cLength,<br />
				   [in, size_is(cLength)] char* id,<br />
				   [in] int s);<br />
};<br />
<br />
[<br />
uuid(AE068C74-0B8B-4041-8CA9-4A590DDDC382),<br />
helpstring("Core Component Library")<br />
]<br />
library Core<br />
{<br />
	importlib("stdole32.tlb");<br />
	importlib("stdole2.tlb");<br />
	<br />
	interface IManager;<br />
}<br />

Now, if I write a C++ app to use this component, doing this, it works great...
(Keep in mind, the component is registered in the registry and the DLL creates an instance of the component by using IClassFactory)

<br />
#include "stdafx.h"<br />
#include <objbase.h><br />
#import "Core.tlb"<br />
<br />
int main(int argc, char* argv[])<br />
{<br />
	HRESULT hr = NULL;<br />
	CLSID clsid;<br />
<br />
	::CoInitialize(NULL);<br />
<br />
	Core::IManager* pManager;<br />
	hr = CLSIDFromProgID(OLESTR("Core.1"), &clsid);<br />
<br />
	if(FAILED(hr))<br />
	{<br />
	     cout << "DLL not installed correctly" << endl;<br />
	}<br />
<br />
	hr = ::CoCreateInstance(clsid, NULL, <br />
                 CLSCTX_ALL, __uuidof(Core::IManager), (void** )&pManager);<br />
<br />
<br />
	if(SUCCEEDED(hr))<br />
	{<br />
		cout << "Found component!" << endl;<br />
<br />
        }<br />
}<br />

No problem, it executes just fine, my C++ app easily uses the component.

Now, I try importing "Core.tlb" into .NET, by using tlbimp.exe, I get a useless managed assembly... After pouring through MSDN article after MSDN article, I've come to the conclusion that its possible to create a COM class wrapper? However, I've had no luck with that as well... This is all I've been able to come up with, but I know it doesn't work...

<br />
namespace Core<br />
{<br />
	[Guid("822A2EDE-09F1-45b8-B80E-A32F21415677"),<br />
		InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]<br />
	interface IManager<br />
	{<br />
		void GetAppName(<br />
			[Out, MarshalAs(UnmanagedType.BStr)] string strAppname,<br />
			[Out] int maxSize);<br />
<br />
		void SetTestPointStatus(<br />
			[In] int MaxLength,<br />
			[In, MarshalAs(UnmanagedType.BStr)] string id,<br />
			[In] int status);<br />
	}<br />
<br />
	[ComImport, Guid("AE068C74-0B8B-4041-8CA9-4A590DDDC382")]<br />
	class CManager<br />
	{<br />
	}<br />
}<br />

Anyone have any suggestions? I've come to the conclusion that I really have no idea what I'm doing in C# as far as interop goes, I'm not a bad C# coder, but this just escapes me at the moment...

Anyway, thanks again for reading this Smile | :)

Re: Please help - COM Interop

mav.northwind6-Jul-05 22:43

mav.northwind

6-Jul-05 22:43

Hi!
In your C# project, just add a reference to your COM object (in project explorer, select "Add reference..." and find your COM class on the COM tab).
VS.NET will create the interop assembly and you can immediately use your COM class.

Typing "Core." should already give you intellisense for IManager, CManager and so on.

Regards,
mav

Re: Please help - COM Interop

metal_rob7-Jul-05 2:15

metal_rob

7-Jul-05 2:15

First, thank you very much for your advice...

Hmmm, I've tried that, but like I said, I don't really have that usable of an interop assembly... It only gives me Core::IManager, just the interface... Do I have to implement that interface, or write a wrapper for that? There are no class objects for me to instantiate... Some sites talk about coclasses, but I have none defined in my IDL file, and I'm not really sure what I'm doing as far as that... haha, am I just doing this wrong?

Thanks again Smile | :)

Re: Please help - COM Interop

mav.northwind7-Jul-05 11:06

mav.northwind

7-Jul-05 11:06

Ok, now that I've taken a second look at the IDL, there in fact isn't a CoClass defined, so all you'll get will be IManager. This is correct so far.
What puzzles me is that you claim that it does work with C++/CoCreateInstance...
I didn't find any class actually implementing IManager, so which class is created by the class factory?

mav

closing the form with the [x] button

marazm16-Jul-05 8:25

marazm1

6-Jul-05 8:25

I have a program, it's a form, a GUI. I need it to close when I hit the x-button in the corner. It is still running in the processes after I close it. How do I permenantly kill the program?

I tried this:

private void ExitButton_Click(object sender, System.EventArgs e)
{
this.Close();
}

thanks very much! Confused | :confused:

Re: closing the form with the [x] button

LongRange.Shooter6-Jul-05 9:26

LongRange.Shooter

6-Jul-05 9:26

You want to register on the Form_Closing event.

private void Form1_Closing(object sender, CancelEventArgs e)<br />
{<br />
   if (should Not Close)<br />
      e.Cancel = true;<br />
}

There are 10 kinds of people in the world.

Those that read binary...

...and those who don't.

Database question

Tom Wright6-Jul-05 8:20

Tom Wright

6-Jul-05 8:20

I'm writing an app that needs to write to a database (database file...like mdf) with out having to install one (like SQL server or Access). Are there any examples on how to do this in C#?

What is the best practice for writing an app that needs database support but is not network aware?

Thanks

Tom Wright
tawright915@yahoo.com

Re: Database question

Anonymous6-Jul-05 8:29

Anonymous

6-Jul-05 8:29

take a look at Firebird
www.firebirdsql.com

it kan be used in embedded mode
so u only need a dll (1,5MB) in the app folder and you have a full RDBMS

Re: Database question

Tom Wright6-Jul-05 8:46

Tom Wright

6-Jul-05 8:46

So do I need to download the .net data provider for framework 1.1? Or is there more to it?

Thanks

Tom Wright
tawright915@yahoo.com

Re: Database question

Luis Alonso Ramos6-Jul-05 8:54

Luis Alonso Ramos

6-Jul-05 8:54

I've used VistaDB in the past. It has only a 500KB footprint, and a fully featured .NET data provider for use with ADO.NET.

Check http://www.vistadb.com[^].

-- LuisR

Luis Alonso Ramos
Intelectix - Chihuahua, Mexico

Not much here: My CP Blog!

Re: Database question

Guffa6-Jul-05 9:01

Guffa

6-Jul-05 9:01

You don't have to install Microsoft Access to use an Access database. The drivers come with windows.

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Re: Database question

Tom Wright7-Jul-05 11:09

Tom Wright

7-Jul-05 11:09

So I can use access and just make my connection string point to a specific file?

Thanks

Tom Wright
tawright915@yahoo.com

Re: Database question

Guffa7-Jul-05 12:29

Guffa

7-Jul-05 12:29

Yes.

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Delete Button in Datagrid

just4ulove76-Jul-05 7:29

just4ulove7

6-Jul-05 7:29

Hi,
How can I add a Delete button to a datagrid, to delete a row?

I added an Edit Command by , its working fine, but how to add a delete command?

Thanks

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