restricting 2nd+ users access to a file - C# Discussion Boards

Re: restricting 2nd+ users access to a file

8-Dec-05 4:01

I'm trying to set things up so that multiple users can access a shared file, but only the first to open the file can get write privlages (the remainder are limited to readonly access).

I'm trying to use the FileSHare property to do this without success. What I tried doing was having the
app first try to open it with FileAccess.ReadWrite and FileShare.Read privlages, and if that failed in with FileAccess.Read FileShare.Read for read only acccess.

What I've discovered is that if the first user has the file open, the 2nd+ users fail due to a permissions failure. I don't understand why though, the first user's allowing readshare privs, and the 2nd is only attempting to open it for read access.

Curtis Schlak.8-Dec-05 4:54

Curtis Schlak.

8-Dec-05 4:54

Good morning!

Have a try with this code. Run it simultaneously on a file whose path you set in the variable path.

string path = @"C:\A\Path\To\A\File\moo.txt";
System.IO.FileStream fs = null;
Exception me = null;
try
{
  fs = new System.IO.FileStream( path,
                                 System.IO.FileMode.Open,
                                 System.IO.FileAccess.ReadWrite,
                                 System.IO.FileShare.Read );
}
catch( Exception )
{
  try
  {
    fs = System.IO.File.Open( path,
                              System.IO.FileMode.Open,
                              System.IO.FileAccess.Read,
                              System.IO.FileShare.ReadWrite );
  }
  catch( Exception e )
  {
    me = e;
  }
}
finally
{
  if( me != null )
  {
    Console.WriteLine( "Error: " + me.Message );
    System.Threading.Thread.Sleep( 10000 );
  }
  else
  {
    Console.WriteLine( "Read: " + fs.CanRead + Environment.NewLine +
                       "Write: " + fs.CanWrite );
    System.Threading.Thread.Sleep( 10000 );
    fs.Close();
  }
}

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

-- modified at 11:34 Thursday 8th December, 2005

Re: restricting 2nd+ users access to a file

Dan Neely8-Dec-05 5:30

Re: restricting 2nd+ users access to a file

8-Dec-05 5:30

Thanks.

Curtis Schlak.8-Dec-05 5:35

Curtis Schlak.

8-Dec-05 5:35

I truly hope that it helps.

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

how to use TOP N in c#.net ?

horacyjr8-Dec-05 3:57

horacyjr

8-Dec-05 3:57

i need a help using crystal.net with c#.net
here is my problem: i want to use TOP N propriety in code on c#.net, but i just know how to do it on crystal, can anybody help me ?

tks

Colin Angus Mackay8-Dec-05 9:18

Colin Angus Mackay

8-Dec-05 9:18

horacyjr wrote:
i want to use TOP N propriety in code on c#.net, but i just know how to do it on crystal, can anybody help me ?

TOP N? In C#? I think you are getting confused with SQL.

In SQL you can do something like this:

SELECT TOP 10 * FROM MyTable

If this is not what you are looking for please clarify your request.

My: Blog | Photos

"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious

Johny Ng8-Dec-05 12:09

Johny Ng

8-Dec-05 12:09

In Sql server, you can specify "N" dynamically but you have to use dynamic query.

Colin Angus Mackay8-Dec-05 12:25

Colin Angus Mackay

8-Dec-05 12:25

Only for SQL Server 2000. In SQL Server 2005 you can specify N with a variable.

SELECT TOP @numRows * FROM MyTable

My: Blog | Photos

"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious

Johny Ng8-Dec-05 12:46

Johny Ng

8-Dec-05 12:46

Good to know. Thanks

leppie8-Dec-05 13:19

leppie

8-Dec-05 13:19

Yeah that one got me on SQL2000 too Frown | :(

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Re: anwer

horacyjr8-Dec-05 23:59

horacyjr

8-Dec-05 23:59

this was the answwer , thanks for helping
http://msdn.microsoft.com/library/default.asp?url=/library/en-s/crystlrf/html/crlrftopbottomnsortfieldclasstopic.asp

private TopBottomNSortField GetTopBottomNSortField
(int sortFieldIndex)
{
TopBottomNSortField topBottomNSortField;

// Get the SortField object by index, cast it as a
// TopBottomNSortField object, and return it.
topBottomNSortField =
Report.DataDefinition.SortFields[sortFieldIndex]
as TopBottomNSortField;
if (topBottomNSortField != null) return topBottomNSortField;
else return null;
}

Decimals missing

Stefan R8-Dec-05 3:42

Stefan R

8-Dec-05 3:42

Hello. I want to do something like this:

float number = 3 / 2;

The problem is that the decimals don't show up, all that is displayed is "1" instead of 1.5. I have tried using float/double/decimal but still the decimals disappear.
What's wrong? Am I missing something here?

Re: Decimals missing

Rob Philpott8-Dec-05 3:52

Rob Philpott

8-Dec-05 3:52

I think you are.

In this expression, the numbers 3 and 2 are integers. If you integer divide 3 by 2 you get 1. This 1 is converted to a float implicitly because no data is lost, but it's not the value you are looking for.

Try:

float number = 3.0 / 2.0;

Regards,
Rob Philpott.

Custom Titlebar

PHDENG818-Dec-05 3:41

PHDENG81

8-Dec-05 3:41

I have a custom title bar that I simply made from a label. My form is fixeddialog so I can get that raised effect. Everything looks great until I minimize my form to the taskbar. When I do this, I only see the corresponding icon and not the text. This is because my borderstyle isn't "none." And to have a fixeddialog form without a titlebar, you must make the text "". Therefore, I came up with this: When I minimize my form, I change the borderstyle and text so that it appears in the taskbar. The trick now is to get it to restore without the Titlebar. Essentially, I just need to do the opposite of what I did when I minimized the form.

So, my question, do I have access to the "restore" event handler that is called when you either click or right-click on the item in the taskbar? If not, does anyone have another solution to this problem? Thanks in advance.

Dan Neely8-Dec-05 3:47

8-Dec-05 3:47

Look at the Resize and SizeChanged events of the form, at least one of them's fired by a resize, although I'm not sure which.

PHDENG818-Dec-05 6:14

PHDENG81

8-Dec-05 6:14

Thanks Dan,

I tried that and it works. However, it flickers quite a bit. Too much to be acceptable. Any ideas? Thanks again.

Dan Neely8-Dec-05 7:06

8-Dec-05 7:06

Not really. there're properties to enable double buffering, but apparently they only work on custom controls and not an entire form. Doing manual resizing for a complex form I was able to largely reduce the flicker by massaging my code to use anchoring and nesting groups of controls in groupboxes as much as possible, and trying different ways to resize/position an object, there didn't appear to be any logic behind why X worked better than Y on control type A, while for B's you wanted to use Y instead.