C# Discussion Boards - CodeProject

leppie1-Nov-02 23:58

leppie

1-Nov-02 23:58

Martin Häsemeyer wrote:
But what I need is a way to store the password so that I can send it to the sql serve and that the server can *understand* it, but my users can't. This means I must be able to decrypt the password without revealing the mechanism to the users...

Pretty clever users Laugh | :laugh:

I understand your problem better now, but cant think of way you can "hide" password... Frown | :(

"There are no stupid question's, just stupid people."

Re: How to enforce db access security?

Martin Haesemeyer2-Nov-02 0:18

Martin Haesemeyer

2-Nov-02 0:18

leppie wrote:
Pretty clever users

Wink | ;)

Yeah I know - but as it is almost sure that no one except myself will use the application it isn't that important anyway - but I'm a little perfectionistic (can you say that in english?) in this way.

Thanks for your thoughts.

Have a nice weekend
Martin

"Situation normal - all fu***d up"
Illuminatus!

Re: How to enforce db access security?

James T. Johnson2-Nov-02 5:04

James T. Johnson

2-Nov-02 5:04

I would create two db user accounts. One with the most basic permissions needed to operate as a normal user. Then create another account that is more privledged.

Store the username/pwd for the first in the program/config file. For the second store just the username and an encrypted version of the password. Base the encryption of the db password on a password you must supply when logging into the program for admin operations. [You need to make sure that when you change the password used to login you re-encrypt the admin db password as well].

A quick look through the Cryptography namespace tells me that the DES algorithm could be used to do what I outline above. There are probably other algorithm's available but that was the first one I found.

James
Sig code stolen from David Wulff

Re: String Methods Seem Broken

David Stone1-Nov-02 11:25

David Stone

1-Nov-02 11:25

The String object is immutable. It cannot be changed. Those methods are not void (meaning they don't return anything) however, they do return a string. So what you need to do is:

string lowerStr = col.ColumnName[0].ToString();
lowerStr = lowerStr.ToLower();
string variableStr = lowerStr + col.ColumnName.Substring(1);

And, it would be even better if you did this:

string lowerStr = col.ColumnName[0].ToString().ToLower();
string variableStr = lowerStr + col.ColumnName.Substring(1);

Hope that helps...

You will now find yourself in a wonderous, magical place, filled with talking gnomes, mythical squirrels, and, almost as an afterthought, your bookmarks
-Shog⁹ teaching Mel Feik how to bookmark

I don't know whether it's just the light but I swear the database server gives me dirty looks everytime I wander past.
-Chris Maunder

How to notify the parent? (passing event to the parent)

Zinj1-Nov-02 9:13

Zinj

1-Nov-02 9:13

This is a question displaying my incompetence.
I cannot figure out how to pass an event to the parent form.
Here is an example. I have a form and a button on it. If the mouse enters the form and event is fired, when the mouse moves over the button, the I want to call the event handler of the parent. I want to generalize this (as if I use a custom button).

Re: How to notify the parent? (passing event to the parent)

John Fisher1-Nov-02 12:35

John Fisher

1-Nov-02 12:35

I think you would have probably figured it out by now if you were thinking in reverse. Instead of asking how you can pass the event to the parent, ask how the parent can susbcribe to the child's event. It's not much different, but it helps to think about it that way.

The functionality you are looking for will be coded the exact same way you code a handler for a button click.

To continue the explanation, you would need something like this (in the parent form):
this.YourButton.MouseEnter += new EventHandler(this.MouseEnteredChild);

Of course, you'd have to have a function in the parent form of the type
private void MouseEnteredChild(object sender, EventArgs args){}

John

Re: How to notify the parent? (passing event to the parent)

Zinj2-Nov-02 9:32

Zinj

2-Nov-02 9:32

Thank you John

Best way to store data?

hammackj1-Nov-02 8:42

hammackj

1-Nov-02 8:42

I am wondering what is the best way to store data like email accounts and what not for a email program(checks if you ahve new mail).

Thanks!

Re: Best way to store data?

TigerNinja_1-Nov-02 11:30

TigerNinja_

1-Nov-02 11:30

it really depends on what exactly your doing with your data. if you are going to be doing a bunch of lookups, then consider a Hashtable, but remember for efficiency to implement your own HashProvider and Comparer.

see Hashtable in MSDN for more information

Soliant | email

"The 'B' in Visual Basic means Beginner" - R. Bischoff

Enumerating Severs on Win9x

mikasa1-Nov-02 7:31

mikasa

1-Nov-02 7:31

I am posting this here in case anyone has an idea or can help...

Ok, I understand that the NetServerEnum API (netapi.dll) functions do not work on a Win9x machine. In VB6, I had code to enumerate Servers on a Windows9x machine, however, porting it to VB.NET seems impossible. I have it working...somewhat. However, it only enumerates the Top-Level Node everytime!

If someone could please shed some light on what I am doing wrong I would greatly appreciate it! This was all guess-work on my part even though I understand Marshalling a little bit.

Here's what I have so far:

'Declarations
'API Declarations
Private Declare Auto Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Integer, ByVal dwBytes As Integer) As Integer
Private Declare Auto Function GlobalFree Lib "kernel32" (ByVal hMem As Integer) As Integer

'API Declarations for Win9x
Private Declare Ansi Function WNetOpenEnum Lib "mpr.dll" Alias "WNetOpenEnumA" (ByVal dwScope As Integer, ByVal dwType As Integer, ByVal dwUsage As Integer, ByRef lpNetResource As IntPtr, ByRef lphEnum As Integer) As Integer
Private Declare Ansi Function WNetEnumResource Lib "mpr.dll" Alias "WNetEnumResourceA" (ByVal hEnum As Integer, ByRef lpcCount As Integer, ByVal lpBuffer As Integer, ByRef lpBufferSize As Integer) As Integer
Private Declare Ansi Function WNetCloseEnum Lib "mpr.dll" (ByVal hEnum As Integer) As Integer

'Structures
<Runtime.InteropServices.StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi)> _
Private Structure NETRESOURCE
Dim Scope As Integer
Dim Type As Integer
Dim DisplayType As Integer
Dim Usage As Integer
Dim LocalName As IntPtr
Dim RemoteName As IntPtr
Dim Comment As IntPtr
Dim Provider As IntPtr
End Structure

'Constants for WNetEnum
Private Enum ResourceScopes
resConnected = &H1 'All currently connected resources (the dwUsage parameter is ignored)
resGlobalNet = &H2 'All resources on the network.
resRemembered = &H3 'All remembered (persistent) connections (dwUsage is ignored)
resRecent = &H4
resContext = &H5
End Enum
Private Enum ResourceTypes
resAny = &H0 'All resources (this value cannot be combined with RESOURCETYPE_DISK or RESOURCETYPE_PRINT).
resDisk = &H1 'All disk resources.
resPrinter = &H2 'All print resources.
resReserved = &H8
resUnknown = &HFFFF
End Enum
Private Enum ResourceUseages 'Ignored if the ResourceScope is not 'resGlobalNet'
resAll = ((&H1) Or (&H2))
resConnectable = &H1
resContainer = &H2
resNoLocalDevice = &H4
resSibling = &H8
resReserved = &H80000000
End Enum
Private Enum ResourceDisplayTypes 'Used to Determine the Resource Type of the NETRESOURCE Struct
resGeneric = &H0
resDomain = &H1
resServer = &H2
resShare = &H3
resFile = &H4
resGroup = &H5
resNetwork = &H6
resRoot = &H7
resShareAdmin = &H8
resDirectory = &H9
resTree = &HA
End Enum

'Enumerations
Public Enum ServerTypes
All = &HFFFFFFFF '/* handy for NetServerEnum2 */
Browsers = &H10000
Browser_Backup = &H20000
Browser_Master = &H40000
Domains = &H80000000
DomainController = &H8
DomainBackController = &H10
DomainMaster = &H80000
DomainMember = &H100
Novell = &H80
NTClusters = &H1000000 '/* NT Cluster */
Servers = &H2 ' All Servers
ServersDialIn = &H400
ServersLocal = &H40000000
ServersPrintQ = &H200
ServersNT = &H8000
ServersSQL = &H4 ' SQL Server
ServersXenix = &H800
ServersUnix = &H800
TimeServers = &H20
Workstations = &H1
WorkstationsNT = &H1000
WorkstationsWin9x = &H400000 '/* Windows95 and above */
End Enum

'Routine to Refresh Servers on a Win9x Machine (uses Recursion)
Private Sub RefreshServersWin9x(Optional ByVal Domain As String = Nothing)
Dim vResource As NETRESOURCE
Dim hResult, hEnum, hBuffer, hPointer, i As Integer
Dim nBufferSize As Integer = 16384, nCount As Integer = &HFFFFFFFF
Const GMEM_FIXED As Integer = &H0
Const GMEM_ZEROINIT As Integer = &H40
Const GPTR As Integer = (GMEM_FIXED Or GMEM_ZEROINIT)

'Initialize the Buffer Pointer
Dim ptrBuffer As IntPtr = IntPtr.Zero, ptrDomain As IntPtr = IntPtr.Zero
If (Not IsNothing(Domain)) AndAlso (Domain.Length > 0) Then
ptrDomain = Marshal.StringToBSTR(Domain)
ptrBuffer = Marshal.AllocCoTaskMem(Marshal.SizeOf(vResource))
vResource.RemoteName = ptrDomain
Call Marshal.StructureToPtr(vResource, ptrBuffer, True)
End If

Try
hResult = WNetOpenEnum(ResourceScopes.resGlobalNet, ResourceTypes.resAny, ResourceUseages.resContainer, ptrBuffer, hEnum)
If (hResult = 0) And (hEnum <> 0) Then 'Successful
'Enumerate the Resource
hBuffer = GlobalAlloc(GPTR, nBufferSize)
hResult = WNetEnumResource(hEnum, nCount, hBuffer, nBufferSize)

If (hResult = 0) Then 'Successful
hPointer = hBuffer
For i = 0 To nCount - 1
'Retrieve the Information for the Resource
vResource = CType(Marshal.PtrToStructure(New IntPtr(hPointer), GetType(NETRESOURCE)), NETRESOURCE)

'Recurse to Find the Servers if this is a Root or Domain Node
Select Case vResource.DisplayType
Case ResourceDisplayTypes.resDomain, ResourceDisplayTypes.resGroup, ResourceDisplayTypes.resNetwork, ResourceDisplayTypes.resRoot
Call Me.RefreshServersWin9x(Marshal.PtrToStringAnsi(vResource.RemoteName))
End Select

'Determine the Next Pointer
hPointer += Marshal.SizeOf(vResource)
Next i
End If
End If
bInitialized = True
Catch
'Call Globals.ErrorMessage("Refresh")
Finally
'Free Up Memory
Call Marshal.FreeCoTaskMem(ptrBuffer)
Call Marshal.FreeCoTaskMem(ptrDomain)

If (hEnum > 0) Then hResult = WNetCloseEnum(hEnum)
If (hBuffer > 0) Then hResult = GlobalFree(hBuffer)
End Try
End Sub

Re: Enumerating Severs on Win9x

TigerNinja_1-Nov-02 11:29

TigerNinja_

1-Nov-02 11:29

maybe try posting this in the VB.NET section

Soliant | email

"The 'B' in Visual Basic means Beginner" - R. Bischoff

Re: Enumerating Severs on Win9x

mikasa1-Nov-02 11:40

mikasa

1-Nov-02 11:40

Nevermind, I figured it out!

Better RichTextBox (or custom textbox)

Bog1-Nov-02 5:48

Bog

1-Nov-02 5:48

The RichTextBox in .net doesn't do what I need- It doesn't let me disable AutoWordSelection (the API is broken), I can't change the default tab space size, I don't think I can rig it to do a line number gutter, and I don't think I can rig it to do syntax highlighting without distrupting the user typing.

That means I have to write a textbox from scratch. That will be a bigger job than the entire rest of my project.

Does anyone know of any tutorials and such about writing a custom textbox in C#/.net?

"Outside of a dog, a book is Man’s best friend. And inside of a dog, it’s too dark to read."
-Groucho Marx

Re: Better RichTextBox (or custom textbox)

Pete Bassett1-Nov-02 6:30

Pete Bassett

1-Nov-02 6:30

Well.

There are lots of sysntax highlighting tuts here and at www.codeguru.com[^] but I think they're all in C++. The actual highlighting isn't that big a deal. I've done it in VB with the normal VB rich text box for an SQL editor and that worked great.

As for the gutter, how about a richtextbox in a usercontrol. Size the control so it leaves the correct gap at the left side and draw your own line numbers there. You can get the size of the text and the number of lines down through the text the RTB is displaying etc etc etc, so that isn't that hard.

As for AutoWordSelection, uuummm, see what you mean.

Pete

Insert Sig. Here!

Re: Better RichTextBox (or custom textbox)

Bog2-Nov-02 5:05

Bog

2-Nov-02 5:05

When you did syntax highlighting, were you able to do it while the user is typing? It seems like I have to select everything I want to change the color of, which would screw up typing...

"Outside of a dog, a book is Man’s best friend. And inside of a dog, it’s too dark to read."
-Groucho Marx

Re: Better RichTextBox (or custom textbox)

Pete Bassett3-Nov-02 7:47

Pete Bassett

3-Nov-02 7:47

Bog wrote:
were you able to do it while the user is typing

Yup. Just disable drawing to the window so none of the results of your selection code is drawn while you're doing it. Then store the actual selection (which will probably just be the current caret location) then run your highlightiong code, changing the selection etc etc etc. Then resore the selection/caret etc and Re-enable drawing to the rich text window.

I handled a couple of cases

1) if the user is just typeing, only highlight the current line. This makes the hightlighting quick.

2) When the RTB gets pasted to, highlight the newly added parts or the whole document.

Have a look at the C++ examples to get a better idea of the process. Failing that, just have a go at it and see how it works.

Pete

Insert Sig. Here!

Re: Better RichTextBox (or custom textbox)

Philip Fitzsimons1-Nov-02 6:54

Philip Fitzsimons

1-Nov-02 6:54

i wonder if its based on the real richtextbox - if it is you could just send it the messages to enable/disable the other features...

"When the only tool you have is a hammer, a sore thumb you will have."

Re: Better RichTextBox (or custom textbox)

Stephane Rodriguez.1-Nov-02 7:07

Stephane Rodriguez.

1-Nov-02 7:07

The RichTextBox class constructor is not marked internal, so you can derive it.

I would suggest you download a free tool like Anakrino[^] to decompile the IL code to C#, as a help to override the methods.

How low can you go ?
(MS rant)

Password in a Propertygrid

Andy Hampshire1-Nov-02 4:00

Andy Hampshire

1-Nov-02 4:00

Hi All,

Probably a stupid qustion Wink | ;)

but...

I've got an object that I'm displaying to the end user via a PropertyGrid control. One of the properties is a Password. I'd like to display this item as "*****" rather than visible text.

Is there anyway of doing this ?

Cheers .. Andy

Re: Password in a Propertygrid

Stephane Rodriguez.1-Nov-02 7:12

Stephane Rodriguez.

1-Nov-02 7:12

You have to write a custom UI type editor[^]. (there is a sample).

How low can you go ?
(MS rant)

Re: Password in a Propertygrid

Andy Hampshire1-Nov-02 7:23

Andy Hampshire

1-Nov-02 7:23

Thanks for the info ... but the link doesn't work for me...

Re: Password in a Propertygrid - HELP !!

Andy Hampshire1-Nov-02 14:22

Andy Hampshire

1-Nov-02 14:22

Well i've managed to find the info and i've tried it out.

The examples i can find give me the ability to render a UI component as a drop down or modal control. I've played with this and have been able to get a TextBox with a password mask just fine.

BUT ... the data in the PropertyGrid is still clear text ! Which is not what i want... this is the text that must be hidden.

Ideas anyone ?

Re: Password in a Propertygrid - HELP !!

leppie1-Nov-02 21:16

leppie

1-Nov-02 21:16

I think you need a type convertor , not a UItype editor. Also the password have to be a class of its own (perhaps, maybe not) and not just a string.

Hope this helps Smile | :)

"There are no stupid question's, just stupid people."

Re: Password in a Propertygrid - HELP !!

Feng Qin3-Nov-02 21:24

Feng Qin

3-Nov-02 21:24

Well, in the normal way, the property can be edited in a textbox, right?
So, we can change its default UITypeEditor to a TextBox which PasswordChar is * or any char you like, by setting some attributes like EditorAttribute on the property you have.
Hope helps to you. Cool | :cool:

I'm amumu, and you?

Not able to fetch first row of excel......

Saroj31-Oct-02 23:33

Saroj

31-Oct-02 23:33

Hello Everybody,

I am trying to import data from Excel sheets through my application.But its not reding the first row of Excel sheet.

Somebody suggested me to set "HDR=No" property in my connection string.
So now my connection string looks as follows,

string strConn;
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" +
"Data Source="+fullPath+";" +
"Extended Properties=Excel 8.0;HDR=No;";

but its giving me following exception

"System.Data.OleDb.OleDbException : Could not find
installable ISAM
at System.Data.OleDb.OleDbConnection.ProcessResults(Int32
hr)
at System.Data.OleDb.OleDbConnection.InitializeProvider()
at System.Data.OleDb.OleDbConnection.Open()
........"

To overcome this error i tried doing following things

I went to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\Excel

location in my windows registery and found following things,

Name Type Data

win32 REG_SZ c:\WINDOWS\System32\msexcl40.dll

then I checked if this "msexcl40.dll" really exist at the path c:\WINDOWS\System32
and it was present there.

Then i uninstalled office2000 from my machine and installed OfficeXP.
Still i am getting the same exception.

Can anybody help me in finding out where i am going wrong or what could be the problem?

Thanks in advance,

Regards,
Saroj

Saroj

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