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My aim is to use the above specified classes for encryption and decryption on strings send across the network.
I am unable to find how to use these two classes put together.
Can anyone help me in this regard. Early response is encouraged.
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Hi,
1) Create the key and IV
2) Create a crypto service provider
3) Create a crypto stream
4) Create new stream writer on the crypto stream
byte [] key ={171, 196, 154, 92, 35, 195, 212, 50};
byte [] IV ={65, 86, 22, 91, 214, 4, 177, 199};
try
{
DESCryptoServiceProvider dsp = new DESCryptoServiceProvider();
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms,dsp.CreateEncryptor(key,IV),CryptoStreamMode.Write);
StreamWriter sw = new StreamWriter(cs);
sw.Write(textBox1.Text);
sw.Flush();
cs.FlushFinalBlock();
ms.Flush();
textBox2.Text = Convert.ToBase64String(ms.GetBuffer(),0, (int)(ms.Length));
}
catch(Exception ex)
{
MessageBox.Show(ex.ToString());
}
Hope this will help you.
Thanks and Regards
SGS
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I am intereseted in developing network application where a server and client will just pass the text messages. I am using Tcp sockets. I could not incorporate networkstream classes in the context. I mean to say that I have to work with networkstream, streamwriter or streamreader and cryptostream classes put together.
Hope you understand the situation.
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Hi there..
There is a lot of examples on how to do the server client stuff in the .Net framework documentation. Search for "TCP" and you'll get something usefull! About the cryptographic stuff:
<br />
public string Encrypt(string ToCrypt)<br />
{<br />
string encoded = "";<br />
byte [] EncKey = {0x16, 0x1F, 0x01, 0x03, 0x1A, 0x0B, 0x10, 0x7F, 0x65, 0x5E, 0x45, 0x3F, 0x11,0x1F, 0xFF, 0xEF, 0x32, 0xEE, 0x5F, 0x38, 0xA7, 0xB2, 0xCC, 0x77, 0x51, 0x14, 0x40, 0x8A, 0x95, 0xE5, 0x00, 0x84};<br />
<br />
byte [] EncIV = {0x05, 0x14, 0x06, 0x15, 0x02, 0x13, 0x00, 0x0F, 0xC0, 0xD8, 0xB6, 0x58, 0xE4, 0xA9, 0x21, 0x5E};<br />
<br />
RijndaelManaged rmEnc = new RijndaelManaged();<br />
rmEnc.Key = EncKey;<br />
rmEnc.IV = EncIV;<br />
<br />
StreamWriter sw = new StreamWriter(encoded);<br />
CryptoStream cs = new CryptoStream(sw, rmEnc.CreateEncryptor(rmEnc.Key, rmEnc.IV), <br />
CryptoStreamMode.Write);<br />
cs.Write(Encoding.ASCII.GetBytes(ToCrypt), 0, ToCrypt.Length);<br />
<br />
cs.Close();<br />
sw.Close();<br />
<br />
return encoded;<br />
}<br />
If this wasen't what you were looking for, you must express yourself more clearly. What is the exact problem?
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Hi Aijaz,
You can initialize the crypto stream class using any class that's derieved from Stream class. (Ex File Stream , Memory Stream, NetworkStream).
Using NetworkStream:
TcpClient client = new TcpClient();
NetworkStream ns = client.GetStream();
CryptoStream cs = new CryptoStream(ns,dsp.CreateEncryptor(key,IV),CryptoStreamMode.Write);
StreamWriter sw = new StreamWriter(cs);
Guess this will help you.
Thanks and Regards
SGS
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Hi All,
I need to export the Chartfx graph which is displayed on a webpage to an excel document(as a graph itself) .How can it be done using C# code??
Can anyone help me out ??
Thanks ,
Sunil
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ChartFX renders and image in ASP.NET, and is nothing like the OLE Chart object that you can embed into Excel. It's simply an image. You could automate downloading and adding the ChartFX-rendered image into Excel, but it won't update when you change data in the worksheet like I'm sure you'd want to happen.
What you need is the data that was used to generate the chart for ChartFX. You could expose this through an XML web service, which Excel could pretty easily import into a worksheet (see the Excel help topics for how to import XML data from a web service, which is outside the scope of this forum) and have an OLE Chart object already embedded.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft
[My Articles] [My Blog]
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WOW, it's Heath Stewart! Haven't seen you around in a while. How are things going at Microsoft?
/\ |_ E X E GG
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I know how to sync the status bar with the coping or some things,
But, any body knows how to do it with a web browser control with loading the web page on custom code ?
I've tried many but ...?
Any ideas ?.
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LongHC wrote:
...with a web browser control with loading the web page on custom code?
What do u mean by custom code?
There are some interesting things u can do with the System.Net namespaces, e.g. u could have a streamreader accosiated to a WebRequest/WebResponse containing the characters of the webpage you are trying to load and have the progress bar progressing after each character is being read from the streamreader.
Have a look
here[^]
Regards,
Polis
Can you practice what you teach?
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I have a word search program.
Each letter in a UserControl.
I want to draw with GDI over the controls to circle words and what not.
Any ideas or links.
Nick
I'm not an expert yet, but I play one at work. Yeah and here too.
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Simply use this.CreateGraphics.(any method you want);
is will be helpful to you,if that is what i exepect
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actually its a bad idea to just create a graphics object. muck like putting an include directive on every file in an MFC application. It upsets the architecture in place.
But I cant draw over the controls still.
my existing code is:
public void frmMain_Paint( object sender, System.Windows.Forms.PaintEventArgs e )
{
//e.Graphics.FillRectangle(new Pen(Brushes.AliceBlue, 2), 50,50,800,800);
e.Graphics.FillRectangle(Brushes.Aqua, 50,50,800,800);
}
which accomplishes the same thing.
But, alas it still doesnt work. I know GDI and directx. Its not the issue,itsw how I either make the control transparent or find a way to bring the grahics to the top.
Nick
I'm not an expert yet, but I play one at work. Yeah and here too.
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But, alas it still doesnt work. I know GDI and directx. Its not the issue,itsw how I either make the control transparent or find a way to bring the grahics to the top.
yeah I tried this before ,
 just make the FillRectangle(Brushes.FromArgb(128,Color.Aqua));
as this number stands to the transparency.
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thanks man
I'm not an expert yet, but I play one at work. Yeah and here too.
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 :->
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Here's my code:
<br />
foreach(GameRoom gr in Room)<br />
{<br />
if (gr.Name.ToLower() == Name.ToLower())<br />
{<br />
return "roomexists";<br />
}<br />
}<br />
"Room" is a hashtable of GameRoom objects. "gr.Name" and "Name" are string values. When this routine is run, and there are more than zero elements in the Room hashtable, I get an Invalid Cast Exception. Being an intermediate programmer, I'm not sure what that means, or exactly why it's being caused.
Any insights?
Thanks for your help.
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foreach in C# compiles to using a collections IEnumerable implementation, where IEnumeration.Current returns an object that (hopefully) casts correctly to whatever type you specify. With a Hashtable, however, foreach compiles to use the Hashtable.GetEnumerator method which returns an IDictionaryEnumerator, where IDictionaryEnumerator.Current returns an IDictionaryEntry, not object. Depending on whether your Game object exists in the key or value of the hashtable, you use IDictionaryEntry.Key or IDictionaryEntry.Value and cast that to your GameRoom type.
You can also use foreach (GameRoom gr in Room.Keys) or foreach (GameRoom gr in Room.Values) depending on whether your object is in the key or value of the hashtable.
I must say you're going about this wrong, however. The reason for using a hashtable is fast lookups, typically on the order of O(1), where your enumeration will be O(n), which is much slower.
For each GameRoom, you should add it and the name with the name as the key and the GameRoom as the value. If you use a case-insentive hash code provider and comparer, you don't have to worry about casing, like in the following example:
Hashtable rooms = new Hashtable(
new CaseInsensitiveHashCodeProvider(),
new CaseInsensitiveComparer();
rooms.Add(gr1.Name, gr1);
rooms.Add(gr2.Name, gr2); Now when you need to get a specific GameRoom, just do something like this:
return rooms["GameRoom1"] as GameRoom; If you want to see if the GameRoom exists, use Hashtable.Contains("GameRoom1"), which is an O(1) operation since it uses the hash code of the name to find the key immediately if available.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft
[My Articles] [My Blog]
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I meant to add that you can learn a lot about your assemblies - and solve problems like this - by using ildasm.exe that ships with the .NET Framework SDK, which is installed by default with Visual Studio and downloadable separately from http://msdn.microsoft.com/netframework[^]. Finding the method in the tree and looking at the implementation would've reveals something like the following example I threw together quickly (does nothing):
.method private hidebysig instance void Example() cil managed
{
.maxstack 2
.locals init (valuetype [mscorlib]System.Collections.DictionaryEntry V_0,
class [mscorlib]System.Collections.IDictionaryEnumerator V_1,
class [mscorlib]System.IDisposable V_2)
IL_0000: ldarg.0
IL_0001: ldfld class [mscorlib]System.Collections.Hashtable Test::table
"color: rgba(255, 0, 0, 1)"> IL_0006: callvirt instance class [mscorlib]System.Collections.IDictionaryEnumerator [mscorlib]System.Collections.Hashtable::GetEnumerator()
IL_000b: stloc.1
.try
{
IL_000c: br.s IL_0029
IL_000e: ldloc.1
"color: rgba(255, 0, 0, 1)"> IL_000f: callvirt instance object [mscorlib]System.Collections.IEnumerator::get_Current()
IL_0014: unbox [mscorlib]System.Collections.DictionaryEntry
IL_0019: ldobj [mscorlib]System.Collections.DictionaryEntry
IL_001e: stloc.0
IL_001f: ldstr "test"
IL_0024: call void [mscorlib]System.Console::WriteLine(string)
IL_0029: ldloc.1
IL_002a: callvirt instance bool [mscorlib]System.Collections.IEnumerator::MoveNext()
IL_002f: brtrue.s IL_000e
IL_0031: leave.s IL_0044
}
finally
{
IL_0033: ldloc.1
IL_0034: isinst [mscorlib]System.IDisposable
IL_0039: stloc.2
IL_003a: ldloc.2
IL_003b: brfalse.s IL_0043
IL_003d: ldloc.2
IL_003e: callvirt instance void [mscorlib]System.IDisposable::Dispose()
IL_0043: endfinally
}
IL_0044: ret
} This may look difficult at first, but you learn over time (just like programming).
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft
[My Articles] [My Blog]
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Most helpful, thank you. It's hard to overstate how beneficial people like you are to us frustrated, fledgling programmers.
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I used the following code to view report.when i view more than 1000 records,crystal viewer look like hand.speed is very slow.How can i improve the method.who can help me?
Pls..
string exeDirectory = Path.GetDirectoryName(Application.ExecutablePath)+@"\Reports\";
ReportDocument rptAll = new ReportDocument();
rptAll.Load(exeDirectory+"GLTaxSum.rpt");
TableLogOnInfo logOnInfo;
ConnectionInfo connectionInfo;
for(int i=0;i
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Does anyone have a way that I can use the "DefineDynamicAssembly" method to create an assembly in a secondary domain so the dynamic assemblies can be unloaded?
Any other methods would be fine also. I just need to run executable code compiled from OpCodes but the problem is, the OpCodes will be compiled many times and the only method I know to do this is to create dynamic assemblies but then I can never unload the assemblies (obviously since they are in the primary AppDomain).
Thanks for any help
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You can call AppDomain.DefineDynamicAssembly on a different AppDomain that is not your current domain, but a problem - a potential security hole, even, if you don't check your domain locations - could result.
From the .NET Framework SDK, pointed to by the documentation[^] for AppDomain.DefineDynamicAssembly:An attempt to call Load on a target application domain that is not the current application domain will result in a successful load of the assembly in the target application domain. Since an Assembly is not MarshalByRefObject, when this method attempts to return the Assembly for the loaded assembly to the current application domain, the common language runtime will try to load the assembly into the current application domain and the load might fail. The assembly that is loaded into the current application domain might be different from the assembly that was loaded first if the path settings for the two application domains are different.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft
[My Articles] [My Blog]
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Thanks for the reply Heath.
I have tried to call "DefineDynamicAssembly" on a secondary AppDomain but I always get a SerializationException. Basically says AssemblyBuilder is not marked as Serializable. I'm guessing that might have something to do with the AppDomainSetup of my new AppDomain. Would could solve that problem?
As for the Load function mentioned above, I dont believe I could use that because I need to generate the compiled code with an AssemblyBuilder, ModuleBuilder, MethodBuilder, etc, and I believe DefineDynamicAssembly is the only way to initialize the AssemblyBuilder to compile OpCodes.
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That's to be expected, based on the quote I posted. The reflection-related classes are not MarshalByRefObject implementation and are not serializable so they cannot be remoted across AppDomain boundaries. In the case of Assembly.Load (from where that quote was taken) an Assembly could be returned, but it will cause the assembly you load to be re-loaded into the current AppDomain. In your case, since you're defining a dynamic assembly there is no assembly to return.
As the exception states, too, AssemblyBuilder is not serializable, just like an Assembly reference you're trying to create.
In short, this isn't really possible doing it like you're trying to do.
That's not to say there isn't a way, however. Create an assembly factory class that is remotable (extends MarshalByRefObject and is attributed with SerializableAttribute and load that into a new AppDomain, then make remoted calls on it in order to create a dynamic assembly. Since the factory exists in the new AppDomain, when it calls DefineDynamicAssembly in will be in the scope of the new AppDomain.
Read Accessing Objects in Other Application Domains Using .NET Remoting[^] for more abour remoting. .NET provides a remoting channel for specifically communicating between AppDomains in the same process, so you do not want to specify a TcpChannel or HttpChannel like you'd use to communicate between two disparate processes, potentially on two different machines.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft
[My Articles] [My Blog]
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