Creating MDB & MDW with ADOX and C# - C# Discussion Boards

Creating MDB & MDW with ADOX and C#

28-Jul-04 2:56

crushinghellhammer wrote:
Is there any difference between these two techniques - casting and ToSingle?

The basic difference is that a cast can thrown an exception which means anytime you cast something you should also wrap it in a try/catch block to handle any exception that is thrown. This in turn emits additional IL instructions, not much but it's there.

- Nick Parker
My Blog | My Articles

ulrich_v27-Jul-04 10:49

ulrich_v

27-Jul-04 10:49

I want to create a secure Access-Database from C#.
I want to create a Database and a Systemdatabase - I suppose this works only in the same time.

Why does the following code not work?

private void button1_Click(object sender, System.EventArgs e)<br />
{<br />
ADOX.Catalog catalog = new ADOX.Catalog();<br />
catalog.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=e:\\new.mdb;Jet OLEDB:System Database=e:\\new.mdw;Jet OLEDB:Create System Database=true");<br />
}

- it creates the e:\new.mdb but fails to create the e:\new.mdw.
the e:\new.mdb is not accessible.

I use Visual Studio 2003 and I have tried this
- on W2K with installed Access97 and Access2000 and
- on WXP with installed Access2003

All with the same result. Dead | X|

Protocol Violation using HttpWebRequest

Amir Zicherman27-Jul-04 9:50

27-Jul-04 9:50

Hi,

In Visual c# 2005 Express, the code below will throw the following exception when accessing www.amazon.com. This does not happen in older versions of the .NET Framework. Why is this happening? Not sure what the violation here is. Using a different program, I can see that the returned headers by amazon.com look like this:

HTTP/1.1 301 Moved Permanently
Date: Tue, 27 Jul 2004 18:54:05 GMT
Server: Stronghold/2.4.2 Apache/1.3.6 C2NetEU/2412 (Unix) amarewrite/0.1 mod_fastcgi/2.2.12
Set-Cookie: skin=; domain=.amazon.com; path=/; expires=Wed, 01-Aug-01 12:00:00 GMT
Location: http://www.amazon.com:80/exec/obidos/subst/home/home.html
Connection: close
Content-Type: text/plain

EXCEPTION:

at System.Net.HttpWebRequest.CheckFinalStatus(Boolean mustThrow)
at System.Net.HttpWebRequest.GetResponse()
at ProtocolViolation.ProtocolViolation.GetHTML(String url_) in c:\documents a
nd settings\administrator\local settings\application data\temporary projects\con
soleapplication1\program.cs:line 21

CODE:

using System;
using System.Net;

namespace ProtocolViolation
{
/// <summary>
/// Summary description for Class1.
/// </summary>
class ProtocolViolation
{

public static string GetHTML(string url_)
{
HttpWebResponse response = null;
HttpWebRequest request = null;
try
{
request = (HttpWebRequest)(WebRequest.Create(url_));
response = (HttpWebResponse)request.GetResponse();
}
catch (Exception e)
{
Console.WriteLine(e);
}
finally
{
if (response != null)
{
response.Close();
}
request = null;
response = null;
}
return "";
}

/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main(string[] args)
{
while (true)
{
GetHTML("http://www.amazon.com:80/exec/obidos/subst/home/home.html");
}
}
}
}

Thanx, amir

Nick Parker27-Jul-04 10:35

27-Jul-04 10:35

Why don't you try something like this:

private string GetHtml(string url)
{
    WebRequest wreq;
    WebResponse wres;
    StreamReader sr;
    String content = string.Empty;
    wreq = HttpWebRequest.Create(url);
    wres = wreq.GetResponse();
    sr = new StreamReader(wres.GetResponseStream());
    content = sr.ReadToEnd();
    sr.Close();
    return content;
}

- Nick Parker
My Blog | My Articles

Amir Zicherman27-Jul-04 14:23

27-Jul-04 14:23

That does not solve the problem. I still get an exception. It would solve it if casting the response would be the cause of the problem. It goes deeper than that into issues with GetResponse(). This is not happening in .NET Framework versions lower than 2.0

You need to DL the C# .NET 2005 Express to see this happening.

Amir

Nick Parker27-Jul-04 18:05

27-Jul-04 18:05

amir z wrote:
You need to DL the C# .NET 2005 Express to see this happening.

I have .NET 2005 running on my laptop, in fact here is a dump from a test program I wrote, which works fine.

#region Using directives

using System;
using System.IO;
using System.Net;
using System.Collections.Generic;
using System.Text;

#endregion

namespace Example
{
    class Program
    {
        static void Main(string[] args)
        {
            Program p = new Program();
            Console.WriteLine(p.GetHtml("http://www.yahoo.com"));
            Console.Read();
        }

        public string GetHtml(string url)
        {
            WebRequest wreq;
            WebResponse wres;
            StreamReader sr;
            String content = string.Empty;
            wreq = HttpWebRequest.Create(url);
            wres = wreq.GetResponse();
            sr = new StreamReader(wres.GetResponseStream());
            content = sr.ReadToEnd();
            sr.Close();
            return content;
        }
    }
}

- Nick Parker
My Blog | My Articles

Amir Zicherman27-Jul-04 18:12

27-Jul-04 18:12

yeah, i never said it doesn't work with every site. so far, i only noticed it happen on amazon.com. go visit http://www.amazon.com with your code. you'll see what happens. and the old framework does not throw any exception when i visit amazon.

-amir

Tom Larsen27-Jul-04 18:39

Tom Larsen

27-Jul-04 18:39

There is nothing about the code that requires .Net 2.0 or Dev Studio 2005.

In any event, the code works for me under both .Net 1.0 and 1.1 against both yahoo and amazon. Are you sure you aren't trying to run this thing behind a firewall?

Amir Zicherman27-Jul-04 20:26

Components, Mouse Events and Abnormal Shapes

27-Jul-04 20:26

I have other reasons for using 2.0. This is just a sample. I know that you can access amazon and yahoo from 1.0 and 1.1.

Like i said, it is only 2.0 that is giving the problem.

thanx, amir

Tristan Rhodes27-Jul-04 6:02

Tristan Rhodes

27-Jul-04 6:02

I'd like to create some controls that have unusual shapes. i.e. Oval, Diamond, picture.
The problem is, all controls appear to be represented as rectangles.

How can I make a control a custom shape? There is no region or size map that I can see that determines what shape a control is, so where does the MouseOver event get it's information?

I was thinking of using some Region map to draw my control, and limit it's painting to that. But i'm not sure where to begin.

Failing this, i would have to create some kind of transparent control, but this leaves me with the problem of custom controls hiding controls they overlap with in transparent areas. I believe this is due to UserControls handling their own paint methods.

Any advice on where to start would be appreciated.

Cata

Re: Components, Mouse Events and Abnormal Shapes

Gary Thom27-Jul-04 7:26

Gary Thom

27-Jul-04 7:26

Use

GraphicsPath to definet the shape, then use control.Region to set the region shape.

Creating Bitmap Regions for Forms and Buttons[^] shows how

Gary

"A fellow with the inventiveness of Albert Einstein but with the attention span of Daffy Duck."
Tom Shales talking about Robin Williams

Initialization in web services

pelos27-Jul-04 5:38

pelos

27-Jul-04 5:38

hello,

My Web Service accesses to a MS SQL database to store and retrieve data from it.
but to store data, first I must to create programatacally the database and the tables. My question is what is the best way to do this? where is the best place to put the code which do this? In the beginning of each Web method (if the database and the tables do not exist, of course) or there is a common place to create or to initialize data, structures, systems, connections, etc.?

thanks in advance.

Re: Initialization in web services

Dave Kreskowiak27-Jul-04 6:42

Dave Kreskowiak

27-Jul-04 6:42

Actually, the best way to do it is to run the SQL script that creates everything either ahead of time, or when the Web Service is installed. Checking for the existance of the database on every call is very unecessary and just wastes time and resources doing the checks for something will only be done once.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Initialization in web services

Nick Parker27-Jul-04 9:28