C# Discussion Boards - CodeProject

Re: Newline in constant error

21-Jun-04 9:54

Accessing indexes requires that an object at that index (or with that index keyword, like the table style or column style name above) exists. If it doesn't, null is returned from the index property. When you try to call a method or access a property on null, you get a NullReferenceException.

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the last free name21-Jun-04 21:37

the last free name

21-Jun-04 21:37

I sometimes see it in a perfectly valid line of code. I simply cut and re-paste the line and the compiler is then happy!

enumerating groups a user belongs to using WinNT://

inyoursadachine21-Jun-04 6:58

inyoursadachine

21-Jun-04 6:58

Hi,
How does one enumerate the groups a user belongs to using the WinNT:// provider (not LDAP) ??

TIA,
Matt

Re: enumerating groups a user belongs to using WinNT://

Dave Kreskowiak21-Jun-04 8:12

Dave Kreskowiak

21-Jun-04 8:12

Well, in VBScript, it looks something like this:

strComputer = "."   ' Use a '.' to denote the local machine.
Set colGroups = GetObject("WinNT://" & strComputer & "")
colGroups.Filter = Array("group")
For Each objGroup In colGroups
    For Each objUser in objGroup.Members
        If objUser.name = "username" Then
            Wscript.Echo objGroup.Name
        End If
    Next
Next

You go through each group on the machine and check to see if the username exists in that group.

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

serializing in c#.net

fatidarya21-Jun-04 6:18

21-Jun-04 6:18

i want serialize and deserialize textbox properties for example font and backcolor,...
please help me and tell me what i do?
thanks

Heath Stewart21-Jun-04 6:38

21-Jun-04 6:38

Read the XmlSerializer class documentation in the .NET Framework SDK. It includes a sample.

XML Serialization will, by default, serialize any public property or field, so serializing those properties is easy:

TextWriter writer = new XmlTextWriter("file.xml",
  System.Text.Encoding.UTF8);
XmlSerializer serializer = new XmlSerializer(textBox1.GetType());
serializer.Serialize(writer, textBox1);

See the documentation for more details.

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fatidarya21-Jun-04 21:31

21-Jun-04 21:31

my code is
this is serialize of textbox:
XmlWriter xw = new XmlTextWriter(fs, System.Text.Encoding.ASCII);
xw.WriteStartElement("Form");
xw.WriteAttributeString("X", theText.Left.ToString());
xw.WriteAttributeString("Y", theText.Top.ToString());
xw.WriteAttributeString("Width", theText.Width.ToString());
xw.WriteAttributeString("Height", theText.Height.ToString());
xw.WriteAttributeString("Value", theText.Text);
xw.WriteAttributeString("Font", theText.Font.Tostring());
xw.WriteAttributeString("Backcolor", theText.Backcolor.Tostring());
xw.WriteEndElement();
XmlNodeReader reader = new XmlNodeReader(doc);reader.value is string but textbox.font or backcolor is Syste.Drawing
please tell me what i do? Confused | :confused:

thanks.

Re:thanks &deserializing in c#.net

thomasa21-Jun-04 22:42

thomasa

21-Jun-04 22:42

I'm not shore about the Font but with the Backcolor you can:
xw.WriteAttributeString("Backcolor", theText.BackColor.ToArgb().ToString());

and read it inn with
theText.BackColor = Color.FromArgb(Convert.ToInt32(reader.Value));

the font you might have to use

theText.Font.Name.ToString()

Hope it helps
Thomas

fatidarya22-Jun-04 0:43

22-Jun-04 0:43

thanks for your help
but i should deserialize font and alignment of my textbox with reader.value ,too
please tell me what i do?
thanks.

Heath Stewart22-Jun-04 2:38

22-Jun-04 2:38

You should be using TypeConverters for the whole thing, otherwise use ToString. Many classes can't be reconstituted from their ToString representations. If you use XmlSerializer as I mentioned, this is all done for you. But, if you insist on doing things the hard way, you can get a TypeConverter reference for each type using something like this:

TypeConverter converter = TypeDescriptor.GetConverter(theText.Left);
xw.WriteAttributeString("X", converter.ConvertToString(theText.Left));
converter = TypeDescriptor.GetConverter(theText.Top);
xw.WriteAttributeString("Y", converter.ConvertToString(theText.Top));
// ...
xw.WriteEndElement();

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fatidarya22-Jun-04 3:00

22-Jun-04 3:00

the serialize code:
xw.WriteAttributeString("Font",theText.Font.Name.ToString());
and it is deserialize code,i use convector but it dosent work properly.
FontConverter ff=new FontConverter();
theTextBox.Font=(System.Drawing.Font )ff.ConvertFromString(reader.Value );
what i do?
thanks.

Heath Stewart22-Jun-04 4:07

22-Jun-04 4:07

You don't instantiate the FontConverter itself, which is documented if you bother to read it. Always use TypeDescriptor.GetConverter.

And instead of saying "doesn't work properly" - which is has in my experience - you might want to be more specific about what's not working, since I can't really help if I don't know what the problem you're having is.

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fatidarya22-Jun-04 19:12

22-Jun-04 19:12

thanks for reply
i use from TypeConvector in my code but c# dosent know it.
my serialize or save code is:
xw.WriteStartElement("TextBox");
xw.WriteAttributeString("X", theText.Left.ToString());
xw.WriteAttributeString("Y", theText.Top.ToString());
xw.WriteAttributeString("Width",c.Width.ToString());
xw.WriteAttributeString("Height",c.Height.ToString()); xw.WriteAttributeString("Value", c.Text);
TypeConverter converter = TypeDescriptor.GetConverter(theText.Font); xw.WriteAttributeString("Font", converter.ConvertToString(theText.Font))
xw.WriteAttributeString("TextAlign",theText.TextAlign.ToString());
xw.WriteAttributeString("Backcolor",c.BackColor.ToArgb().ToString());
xw.WriteAttributeString("Forecolor",c.ForeColor.ToArgb().ToString());
xw.WriteEndElement();
and my deserialize or read code is:
for (int i = 0; i < reader.AttributeCount; i++)
{
reader.MoveToAttribute(i); switch(reader.Name)
{
case "X":
theTextBox.SetBounds(Convert.ToInt32(reader.Value),
theTextBox.Top, theTextBox.Width, theTextBox.Height);
break; case "Y": theTextBox.SetBounds(theTextBox.Left,
Convert.ToInt32(reader.Value), theTextBox.Width,theTextBox.Height); break;
.. case "Font": TypeConverter ff = TypeDescriptor.GetConverter(reader.value);
theTextBox.Font=(System.Drawing.Font)ff.ConvertFromString (reader.Value );
break;
case "Backcolor":
theTextBox.BackColor= Color.FromArgb(Convert.ToInt32(reader.Value));
break;
please tell me,what i do for my deserialize code?

Heath Stewart22-Jun-04 19:19

22-Jun-04 19:19

So what exactly is the error? Be specific. What's the exceptio type, if any? What's the exception message read.

And as I said originally, you really should be 1) using a TypeConverter for everything (this is what the XML Serialization routines do), or 2) just using the XmlSerializer, which takes care of all this for you. All that code you've typed could be wrapped up into 3 or 4 lines. use what's available in the BCL unless you have a good reason for re-implementing everything yourself.

Microsoft MVP, Visual C#
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Attempting to implement Keyed MD-5 Hash

Stefan Troschuetz21-Jun-04 20:44

Stefan Troschuetz

21-Jun-04 20:44

Also take a look at BinaryFormatter and SoapFormatter classes which can be used to serialize objects to a stream e.g. a filestream.
They cannot be used to serialize a whole TextBox instance as it's not marked as serializable, but they work with specific fields as most of them are simpler types which can be serialized.

www.troschuetz.de

Java script in c#

_Searcher_21-Jun-04 5:53

_Searcher_

21-Jun-04 5:53

Hi

I want to reload a page with a button. The page I wish to reload lies in an i frame, the button that I wish to use to reload lies in another i frame. I have this code in the *.aspx file and it works. The code lies behind a link, and I wish to have it behind a button.

href="javascript:location.reload()" target="sub_top"

can I use this code in code-behind? how do I do this?

Thanks!

-- Evil geniuses for a better tomorrow --

Re: Java script in c#

Dave Kreskowiak21-Jun-04 6:10

Dave Kreskowiak

21-Jun-04 6:10

No, you can't use that code in the code-behind. Since the code-behind will regenerate the entire HTML page anyway, you'll just end up loading the entire frameset. You're better off putting that code in the onclick handler of a button.

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

selil21-Jun-04 5:29

selil

21-Jun-04 5:29

Code project C# guru’s Confused | :confused:

,

I am attempting to implement RFC 2095 ( http://www.ietf.org/rfc/rfc2095.txt ) I’ve found what I believe is an error in the crypto library for C#.

Now be kind I’ve been coding C# for exactly 1 week OMG | :OMG:

, and it has been about 7 years since I coded in production Eek! | :eek:

. The last time I coded was in VI on Unix. This is just one of the methods I’m attempting to implement in this project. The rest of the project includes an SMTP server, and verification schema.

I’m implementing the procedures in a C# program found in RFC 2095, and using the CRAM algorithm found in http://www.ietf.org/rfc/rfc2104.txt . The test data strings found in RFC 2095 include a share key string “tanstaaftanstaaf” and the challenge “<1896.697170952@postoffice.reston.mci.net>” these test values should produce according to the test in the RFC the hashed hex output “b9 13 a6 02 c7 ed a7 a4 95 b4 e6 e7 33 4d 38 90” .

In the following program from the MSDN code library (ms-help://MS.VSCC.2003/MS.MSDNQTR.2003FEB.1033/cpguide/html/cpconextendingkeyedhashalgorithmclass.htm) I get the following output from the output string B9 13 A6 2 C7 ED A7 A4 95 B4 E6 E7 33 4D 38 90 on the test case. And, of course the fourth hex pair has dropped the leading zero D'Oh! | :doh:

.

That would be wrong according to the Keyed MD-5 hash algorithm Mad | :mad:

. The leading zero should be left in place. From my feeble attempts at debugging it looks like it is either the output of the HEX according to Microsoft or internal to the crypto library. Either way how do I make sure that it does not drop that leading zero Dead | X|

?

Thanks in advance,

Sam

From the MSDN Code Library with RFC 2095 Edits
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

using System;
using System.Security.Cryptography;

public class TestHMACMD5
{
static private void PrintByteArray(Byte[] arr)
{
int i;
Console.WriteLine("Length: " + arr.Length);
for (i=0; i<arr.length; i++)=""
="" {
="" console.write("{0:x}",="" arr[i]);
="" console.write("="" ");
="" if="" (="" (i+9)%8="=" 0="" )="" console.writeline();
="" }
="" (i%8="" !="0)" public="" static="" void="" main()="" create="" a="" key.
="" byte[]="" key1="{0x0b," 0x0b,="" 0x0b};
="" pass="" the="" key="" to="" constructor="" of="" hmacmd5="" class.="" hmac1="new" hmacmd5(key1);

="" another="" added="" test="" case="" for="" rfc="" 2095

="" key2="System.Text.Encoding.ASCII.GetBytes("tanstaaftanstaaf");" hmac2="new" hmacmd5(key2);

="" encode="" string="" into="" byte="" array,="" hash="" array,
="" and="" print="" screen.
="" data1="System.Text.Encoding.ASCII.GetBytes("KeyString" printbytearray(hmac1.computehash(data1));

="" 2095
="" data2="System.Text.Encoding.ASCII.GetBytes("<1896.697170952@postoffice.reston.mci.net">");
PrintByteArray(hmac2.ComputeHash(data2));
}
}
public class HMACMD5 : KeyedHashAlgorithm
{
private MD5 hash1;
private MD5 hash2;
private bool bHashing = false;

private byte[] rgbInner = new byte[64];
private byte[] rgbOuter = new byte[64];

public HMACMD5 (byte[] rgbKey)
{
HashSizeValue = 128;
// Create the hash algorithms.
hash1 = MD5.Create();
hash2 = MD5.Create();
// Get the key.
if (rgbKey.Length > 64)
{
KeyValue = hash1.ComputeHash(rgbKey);
// No need to call Initialize, ComputeHash does it automatically.
}
else
{
KeyValue = (byte[]) rgbKey.Clone();
}
// Compute rgbInner and rgbOuter.
int i = 0;
for (i=0; i<64; i++)
{
rgbInner[i] = 0x36;
rgbOuter[i] = 0x5C;
}
for (i=0; i<keyvalue.length; i++)=""
="" {
="" rgbinner[i]="" ^="KeyValue[i];
" rgbouter[i]="" }=""

="" public="" override="" byte[]="" key="" get="" {="" return="" (byte[])="" keyvalue.clone();="" }
="" set="" if="" (bhashing)="" throw="" new="" exception("cannot="" change="" during="" hash="" operation");
="" (value.length=""> 64)
{
KeyValue = hash1.ComputeHash(value);
// No need to call Initialize, ComputeHash does it automatically.
}
else
{
KeyValue = (byte[]) value.Clone();
}
// Compute rgbInner and rgbOuter.
int i = 0;
for (i=0; i<64; i++)
{
rgbInner[i] = 0x36;
rgbOuter[i] = 0x5C;
}
for (i=0; i

Heath Stewart21-Jun-04 5:42

21-Jun-04 5:42

The bug is in your code. If MD5 didn't work once, it wouldn't work for any plain text.

Use Console.Write("{0:X2}", arr[i]) instead of just using "{0:X}" for the format specifier. This makes sure that 2 chars are used per bit.

Also, it's faster to use arr[i].ToString("X2") in this case, and this is typically true when you need to format only one value. Why? Because using Console.Write (or any of the formatting methods) instantiates a StringBuilder and does some having parsing to eventually call Byte.ToString(string, IFormatProvider), which you could just do directly here (though you don't need to pass an IFormatProvider in this case).

It's best you don't claim bugs, especially when you've only been programming C# for 1 week. Check out the documentation, search the 'net for similar findings, and ask someone to verify (like on this forum), then declare you've found a bug and report it to the proper channels.

Microsoft MVP, Visual C#
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selil21-Jun-04 6:00

selil

21-Jun-04 6:00

Heath Stewart wrote:
It's best you don't claim bugs, especially when you've only been programming C# for 1 week. Check out the documentation, search the 'net for similar findings, and ask someone to verify (like on this forum), then declare you've found a bug and report it to the proper ch

First. Thank you very much.

Second. I was using the example code from Microsoft on their implemenatation of the correct code (which is still obviously wrong according to the RFC). I did check the net for this very topic (very thin and obscure task). I did ask somebody to verify but they were looking at the entire code and easily missed the problem.

Third. It was an obvious small error on my part that I should have caught. I just never figured that Microsoft would provide a sample of an RFC that wasn't compliant. That is exactly why I thought to ask the kind folks here at Code Project for help.

Fourth I wasn't claiming a bug and was looking for the exact validation you provided in that the Microsoft code as supplied was wrong and not something deeper. They should change that one item to make it RFC compliant.

Fifth. Thanks again. Sorry if you thought I was calling your baby ugly. Haven't you ever beat your head on the keyboard looking at the obvious to somebody else while completely missing the EASY! answer?

Again thank you very much for the help.... Now to finish the project. And, I think C# is pretty darn nifty......Thanks again, and again.... Really...

--------------------
Sam

Heath Stewart21-Jun-04 6:34

21-Jun-04 6:34

The samples in the documentation is riddled with bugs. Look at it - hopefully it helps you to understand if the class documentation doesn't - but never copy it.

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Dave Kreskowiak21-Jun-04 5:52

Dave Kreskowiak

21-Jun-04 5:52

selil wrote:
static private void PrintByteArray(Byte[] arr)
{
int i;
Console.WriteLine("Length: " + arr.Length);
for (i=0; i {
Console.Write("{0:X}", arr[i]);
Console.Write(" ");
if ( (i+9)%8 == 0 ) Console.WriteLine();
}
if (i%8 != 0) Console.WriteLine();
}

This is happening because the format specifier in {0:X} is dropping the leading zero. The value is represented with the leading zero (obviously, since the value is 2), but the leading zero is just not printed.

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