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First off I'm new to this development platform so I don't know some of the most obvious fixes for known problems. Anyway, I've developed an application in C# that creates/accesses text files and utilizes the Microsoft Access database. My application runs fine on XP but fails with file access permission failures on Windows 2000 professional (the only other platform I've had access to to try). The .Net framework 1.1 is loaded on the machine and the application comes up with no problems. Only when I try to access a file I start having problems. Is there someting obvious I'm missing? Something particular to Windows 2000 I need to understand? I can't be the only one who has had this problem....can I?
Any help/insight would be appreciated.
Parrish
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Is your app running on the 2000 machine loaded from a network share on the XP machine? If so, that's where your problem is. Since the netowkr machine isn't a trusted server, your code will not have the same access to the system as if it were launched from the 2000 box.
RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Gnome
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It's running on a Windows 2000 professional network. No XP involved at all.
Thank you for your quick reply.
Parrish
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Also (regarding what Dave said), the file permissions may be different. If your MDB (Jet Database, aka "Access database") is in a directory where you don't have write permissions, then you must change the permissions on that directory.
If you're accessing the file over the network, then your code must have a FileIOPermission that allows access to that resource. This deals with Code Access Security in .NET - a sandbox of sorts that makes it a secure framework. See the article, Understanding .NET Code Access Security[^], for more information.
Microsoft MVP, Visual C#
My Articles
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Thank you very much. I read up on it.
Parrish
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I am trying to write/create a form that takes up the full screen of my pocket pc. In other words the form must obsecure both task bars (bottom and top) of the screen. I cannot get this to work on startup. If I focus off the form by calling up another app and then re-activate - the form becomes full screen. Subsequent forms called from the original startup form behave in a similar fashion.
Can anyone help?
RMe
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A simple have would be to call Form.Activate when your form is loaded.
The correct way requires that you override the CreateParams property, get the base.CreateParams, and modify the Windows styles (which property you set the style using a bitwise OR depends on which style you set - see the Windows CE SDK), then return your CreateParams structure. This the typical way in Windows Forms on non-CE machines.
Microsoft MVP, Visual C#
My Articles
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Thanks for the response Heath - but I am missing something. This is what I have done.
1. I create a new, empty Smart Device Project
2. I add a windows form to the project
3. I make sure that the window is maximised in the properties
4. I build and deploy on my Pocket PC
I don't see where I get access to Form.Activate. What has bothered me is that the MS help states that the Form.WindowState property is set to normal by default regardless of its initial setting.
RMe
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Sorry, Activate isn't supported on the .NET CF. You'll probably have to P/Invoke SendMessage and send the WM_ACTIVATE message.
Microsoft MVP, Visual C#
My Articles
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Thanks for the correspondence Heath - however in the meantime I have figured it out. I created an event handler for Form.Load which as you know occurs before the form is displayed for the first time. In the event handler I change the WindowState of the form to maximised, invalidate the screen and ask for an update. This seems to do it for me nicely. See code
//the Event handler
this.Load += new System.EventHandler(this.welcome_Load);
private void welcome_Load(object sender, System.EventArgs e)
{
this.WindowState = System.Windows.Forms.FormWindowState.Maximized;
this.Invalidate();
this.Update();
}
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Hi folks,
I was recently reading Michael Kennedy's article, "Global System Hooks in .NET" [link], and I got to thinking:
If a global system hook injects the same stub of code into every running process in order to intercept the messages when they reach the process, wouldn't it be smarter to intercept the message before it was even dispatched to the process?
You'll have to forgive my ignorance here; I have next to no knowledge of the Messaging framework!
But, back on track, that thought struck me as quite odd. Surely it would be better to intercept it at a choke point rather than cater for every possible location? And if that was the case, surely it would also mean you wouldn't unnecessarily slow down the other processes on the system? Is that actually possible? Or do I simply not understand at all (quite likely  )
Again, this is just a thought - like I said, I have no knowledge of the internals of Windows' messaging system 
Thanks for any comments,
-Adam Goossens.
This space for rent.
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Adam Goossens wrote:
Surely it would be better to intercept it at a choke point rather than cater for every possible location? And if that was the case, surely it would also mean you wouldn't unnecessarily slow down the other processes on the system?
That's the pitfall for using a global hook. If you monitor the system for a specific message to a specific window, a global hook is not an appropriate solution. Global hooks are more for, say, monitoring the the system for keyboard events, mouse events, ...
I've used it to disable the Window key on our keyboards since there are keyboard shortcuts to launch Explorer even though policy has launching Explorer prohibited. This was a low level keyboard hook that intercepted keyboard messages before they were dispatched to the system.
If written properly and by that, I mean very efficiently, you'd never know the hook was there. Improperly written hooks, on the other hand, can seriously degrade performance. The keyboard hook I wrote just examined the keys coming from the keyboard driver and didn't pass along the key combinations that we needed it to suppress. This hook never showed a single second of consumed CPU time during the entire time it has been running, so it works really fast.
RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Gnome
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Well, that's the thing, global hooks are using the "choke" points. Every app has its own message queue. Even threads have their own queue. The system itself has no queue. So, if you want to capture something globally, you have to put something into each app. No other way around it, unfortuneately.
Now, I'm not sure if this is a confusing point, but the "Messaging framework" is a different beast than "windows messaging". The messaging framework is a service that distribute messages using tcp/ip. The windows messaging is for the gui/user interaction. The two have absolutely nothing in common other than running on Windows machines.
I hope I've cleared things up. If not, well.... ask! 
--
Joel Lucsy
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Well, that's the thing, global hooks are using the "choke" points. Every app has its own message queue. Even threads have their own queue. The system itself has no queue. So, if you want to capture something globally, you have to put something into each app. No other way around it, unfortuneately.
Ah! That's what I was looking for  . I was under the impression the system would have it's own queue where the messages were received from the hardware, processed, and then dispatched to the appropriate process/thread. Since this isn't the case, the idea of inserting that code stub into each process to catch them makes sense. Fair enough.
Now, I'm not sure if this is a confusing point, but the "Messaging framework" is a different beast than "windows messaging". The messaging framework is a service that distribute messages using tcp/ip.
Whoops, that's me talking about things I know nothing about again!  I didn't know there was such a thing as the Messaging framework to be honest
Kudos to both of you for the quick and detailed responses! Much appreciated!
This space for rent.
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hai there,
i need your valuable information.
i would like to create a text editor using c#.
i got a trouble in displaying line numbers on left side of the TextBox
Also i want the feature 'Add Breakpoint' in a panel near the texteditor.
How can we get the position of a cursor with respect to the control.
Thanks in advance.
Regards,
Shaju 
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I suggest you take a look at some open-source applications. You could find a horde of examples on http://www.sourceforge.net[^]. There's no "standard" way of doing this and it greatly depends on your implementation.
Microsoft MVP, Visual C#
My Articles
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Have a look at mine (see link below) It's a helluva lot harder than you mite think (dont look at silly implementations that use a seperate control for line numbers, like #develop)
top secret xacc-ide 0.0.1
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dear friends
i am a new to c#..
plz help me how to run the algorithm whose source code is given in c#. e.g. the source code for the cyclic redundancy check is given in this site..
plz tell me the step by step procedure to run it..
with regards
from gcm
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You should probably ask in the forum for the individual article.
However, I can't imaging why you'd want to run a CRC algorithm on its own, so I can only assume you want to integrate it with something else. It might be better for you to convert the algorithm to the language of your choice.
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar
The Second EuroCPian Event will be in Brussels on the 4th of September
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Hi Friends,
I am working on Visual C# .NET. I want to insert one value in Registry and then retrive that value from registry. In VB.NET there is a funtion "SAVESETTING" to store values in registry. Is there any funtion to store values in registry and retriving that values from registry.
If u have any solution for this then please give reply as early as possible
Thank You
Hemant Mane.
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I found this brilliant piece of code by Francesco Natali when I was looking for an easy way out.
/* ***************************************
* ModifyRegistry.cs
* ---------------------------------------
* a very simple class
* to read, write, delete and count
* registry values with C#
* ---------------------------------------
* if you improve this code
* please email me your improvement!
* ---------------------------------------
* by Francesco Natali
* - fn.varie@libero.it -
* ***************************************/
using System;
// it's required for reading/writing into the registry:
using Microsoft.Win32;
// and for the MessageBox function:
using System.Windows.Forms;
namespace Utility.ModifyRegistry
{
///
/// An useful class to read/write/delete/count registry keys
///
public class ModifyRegistry
{
private bool showError = false;
///
/// A property to show or hide error messages
/// (default = false)
///
public bool ShowError
{
get { return showError; }
set { showError = value; }
}
private string subKey = "SOFTWARE\\" + Application.ProductName.ToUpper();
///
/// A property to set the SubKey value
/// (default = "SOFTWARE\\" + Application.ProductName.ToUpper())
///
public string SubKey
{
get { return subKey; }
set { subKey = value; }
}
private RegistryKey baseRegistryKey = Registry.LocalMachine;
///
/// A property to set the BaseRegistryKey value.
/// (default = Registry.LocalMachine)
///
public RegistryKey BaseRegistryKey
{
get { return baseRegistryKey; }
set { baseRegistryKey = value; }
}
/* **************************************************************************
* **************************************************************************/
///
/// To read a registry key.
/// input: KeyName (string)
/// output: value (string)
///
public string Read(string KeyName)
{
// Opening the registry key
RegistryKey rk = baseRegistryKey ;
// Open a subKey as read-only
RegistryKey sk1 = rk.OpenSubKey(subKey);
// If the RegistrySubKey doesn't exist -> (null)
if ( sk1 == null )
{
return null;
}
else
{
try
{
// If the RegistryKey exists I get its value
// or null is returned.
return (string)sk1.GetValue(KeyName.ToUpper());
}
catch (Exception e)
{
// AAAAAAAAAAARGH, an error!
ShowErrorMessage(e, "Reading registry " + KeyName.ToUpper());
return null;
}
}
}
/* **************************************************************************
* **************************************************************************/
///
/// To write into a registry key.
/// input: KeyName (string) , Value (object)
/// output: true or false
///
public bool Write(string KeyName, object Value)
{
try
{
// Setting
RegistryKey rk = baseRegistryKey ;
// I have to use CreateSubKey
// (create or open it if already exits),
// 'cause OpenSubKey open a subKey as read-only
RegistryKey sk1 = rk.CreateSubKey(subKey);
// Save the value
sk1.SetValue(KeyName.ToUpper(), Value);
return true;
}
catch (Exception e)
{
// AAAAAAAAAAARGH, an error!
ShowErrorMessage(e, "Writing registry " + KeyName.ToUpper());
return false;
}
}
/* **************************************************************************
* **************************************************************************/
///
/// To delete a registry key.
/// input: KeyName (string)
/// output: true or false
///
public bool DeleteKey(string KeyName)
{
try
{
// Setting
RegistryKey rk = baseRegistryKey ;
RegistryKey sk1 = rk.CreateSubKey(subKey);
// If the RegistrySubKey doesn't exists -> (true)
if ( sk1 == null )
return true;
else
sk1.DeleteValue(KeyName);
return true;
}
catch (Exception e)
{
// AAAAAAAAAAARGH, an error!
ShowErrorMessage(e, "Deleting SubKey " + subKey);
return false;
}
}
/* **************************************************************************
* **************************************************************************/
///
/// To delete a sub key and any child.
/// input: void
/// output: true or false
///
public bool DeleteSubKeyTree()
{
try
{
// Setting
RegistryKey rk = baseRegistryKey ;
RegistryKey sk1 = rk.OpenSubKey(subKey);
// If the RegistryKey exists, I delete it
if ( sk1 != null )
rk.DeleteSubKeyTree(subKey);
return true;
}
catch (Exception e)
{
// AAAAAAAAAAARGH, an error!
ShowErrorMessage(e, "Deleting SubKey " + subKey);
return false;
}
}
/* **************************************************************************
* **************************************************************************/
///
/// Retrive the count of subkeys at the current key.
/// input: void
/// output: number of subkeys
///
public int SubKeyCount()
{
try
{
// Setting
RegistryKey rk = baseRegistryKey ;
RegistryKey sk1 = rk.OpenSubKey(subKey);
// If the RegistryKey exists...
if ( sk1 != null )
return sk1.SubKeyCount;
else
return 0;
}
catch (Exception e)
{
// AAAAAAAAAAARGH, an error!
ShowErrorMessage(e, "Retriving subkeys of " + subKey);
return 0;
}
}
/* **************************************************************************
* **************************************************************************/
///
/// Retrive the count of values in the key.
/// input: void
/// output: number of keys
///
public int ValueCount()
{
try
{
// Setting
RegistryKey rk = baseRegistryKey ;
RegistryKey sk1 = rk.OpenSubKey(subKey);
// If the RegistryKey exists...
if ( sk1 != null )
return sk1.ValueCount;
else
return 0;
}
catch (Exception e)
{
// AAAAAAAAAAARGH, an error!
ShowErrorMessage(e, "Retriving keys of " + subKey);
return 0;
}
}
/* **************************************************************************
* **************************************************************************/
private void ShowErrorMessage(Exception e, string Title)
{
if (showError == true)
MessageBox.Show(e.Message,
Title
,MessageBoxButtons.OK
,MessageBoxIcon.Error);
}
}
}
JV
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Hi all,
I am trying to create a custom project for Visual Studio.Net. Basically, what I need is for a specific kind of project to appear within the wizard and then I need for my specific kind of code page (like .cs pages, .cpp pages), corresponding to a particular extension, to appear and to be able to work with it.
Any ideas on this one?
Any help would be greatly appeciated.
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This question is better suited to the VS.NET IDE forum.
In either case, I don't have a clue what your trying to accompish...
Are you trying to write your own project template? Like a Windows Forms Application or a Web Forms Application...
RageInTheMachine9532
"...a pungent, gastly, stinky piece of cheese!" -- The Roaming Gnome
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How I figured it out (and use it quite often) - go to the installation directory for the VC# or VB.NET in the Visual Studio .NET directory and look at the file structure. Creating a new project or item type is as simple as defining a .vsdir file that points to the wizard files in a sibling directory. These files are either simple templates or contain multiple files that you can use variable replacement. VS.NET defines several variables and you can define your own using a set of HTML files for any wizards and a/some javascript file(s).
If you want more information beyond what you can discover for yourself, you'll need to get Visual Studio .NET Enterprise Architect which includes templates and documentation for creating templates. There is some vague information in MSDN Library[^] about this, but it doesn't tell you much beyond what you can discover and most of the time refers you to use the Enterprise Architect project for creating templates.
Microsoft MVP, Visual C#
My Articles
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