C# Discussion Boards - CodeProject

String conversion to DBNull.Value

20-Oct-05 1:31

As the value can be different types of objects, use the object base class, and check the type of the object:

public static string CheckStringForDBNulls(object strCheckString) {<br />
	if (strCheckString is DBNull) {<br />
		return string.Empty;<br />
	} else {<br />
		return ((string)strCheckString).Trim();<br />
	}<br />
}

---
b { font-weight: normal; }

Brendan Vogt19-Oct-05 23:35

Brendan Vogt

19-Oct-05 23:35

Hi,

I tried the following function, but it doesn't want to work:

//*********************************************************************
//
// CheckStringForDBNulls Static Method
//
// The CheckStringForDBNulls method checks if a string contains a value, if not it
// returns DBNull.Value, or the value of the string.
//
//*********************************************************************

public static DBNull CheckStringForDBNulls(string strCheckString)
{
if(strCheckString.Trim() != string.Empty)
return strCheckString.Trim();
else
return DBNull.Value;
}

Could you please let me know what I am doing wrong? This is used to check the parameter being added, if it contains nothing, the make the value DBNull.Value, or use the value of thr string.

Thanks
BRENDAN

-- modified at 5:46 Thursday 20th October, 2005

Dead Skin Mask20-Oct-05 0:13

Dead Skin Mask

20-Oct-05 0:13

the return type of this method is DBNull, so you can only ever return a null value..
i suspect you don't really need a static method to perform this check, and could probably get away with something like this instead :

if(string.IsNullOrEmpty(strCheckString))<br />
    object = DBNull.Value;<br />
else<br />
    object = strCheckString;

Brendan Vogt20-Oct-05 0:40

Brendan Vogt

20-Oct-05 0:40

I want to put this into a function because I have a 20 checks, and the code can get very long.

Please put the above mentioned code in a function.

Dead Skin Mask20-Oct-05 1:28

Dead Skin Mask

20-Oct-05 1:28

I don't know how well it would work but you could try making your method return Object

AudioVideoPlayback: Video as texture. Unable to Dispose()

Brendan Vogt20-Oct-05 2:16

Brendan Vogt

20-Oct-05 2:16

This was how I initially had it, I just thought there might be another way. But thanks for your help, I appreciate it!!

Pixinger7719-Oct-05 23:15

Pixinger77

19-Oct-05 23:15

Hi,

During the last days i strugled around with a strange problem.
I need to play an video on a 3D-Object. That doesnt sound that hard. I created an device as common, added some data to the vertex buffer and activated the texture support of the Video Class:

video.TextureReadyToRender += new TextureRenderEventHandler(video_TextureReadyToRender);<br />
video.RenderToTexture(device);

Immediatly after the RenderToTexture call, the TextureReadyToRender Event was fired and I was able to render my desired scene. So far so goo, no problems at all. It works absolut perfectly Big Grin | :-D

But when I want to close my application I'm not able to clean up. Everytime when me (or the framework) wants to call the Dispose() method, an NullReferenceException is throwed.

I googled around a lot but couldn't find an answer. Does someone know perhaps an easy example? I tried to work with the Example from MDX-SDK(Summer2004), but because of the complicated framework structure I wasn't able to figure out too much. Does anyone have the same problem? D'Oh! | :doh:

XML File encryption

rmedo19-Oct-05 22:49

rmedo

19-Oct-05 22:49

Hi all,

I want to know how can i encrypt the whole XML file, it means that the data inside this file can't be understood with any user if he try to open this file (Ex.112364896fgdf64965)
if anyone know please help me Smile | :)

Guffa19-Oct-05 23:35

19-Oct-05 23:35

Take a look at the System.Security.Cryptography namespace.

---
b { font-weight: normal; }

rmedo23-Oct-05 2:03

rmedo

23-Oct-05 2:03

Hi,
i saw this namespace and i didn't found what i want , it makes only encryption for XMLElements and i want to incrypt the whole file to be in octet stream

Thanks for your help

Guffa24-Oct-05 21:24

24-Oct-05 21:24

There is no special method for encrypting an xml document. Just get the xml document as a string, and encrypt it.

---
b { font-weight: normal; }

Regarding Resolving IP Address

rmedo24-Oct-05 22:53

rmedo

24-Oct-05 22:53

Thanks alot for your help

A.Grover19-Oct-05 21:19

A.Grover

19-Oct-05 21:19

i am working with c# console application.i am using MInternetExplorer.Explorer class of SHocVw.dll.basically i am parsing html pages.i am using following events as per my requirement

BeforeNavigate2()
DocumentComplete()

i would like to resolve the IP address of website.i used the following code for resolving IP Address

IPHostEntry IPHost =Dns.Resolve("http://www.yahoo.com");

// after that code is not executing
IPAddress[] addr=IPHost.AddressList;
for(int i= 0; i

leppie19-Oct-05 22:38

leppie

19-Oct-05 22:38

Amit_CDAC_Grover wrote:
Dns.Resolve("http://www.yahoo.com");

Hostnames do not include the http:// part.

^{xacc-ide 0.0.99-preview7 now with C#, C, C++, IL, XML, Nemerle, IronPython, Perl, Caml, SML, Ruby, Flex, Yacc, Java, Javascript, Lua, Prolog and Boo highlighting support!}

A.Grover19-Oct-05 23:03

A.Grover

19-Oct-05 23:03

i have also tried with Dns.Resolve("www.yahoo.com") but that is also not working.

Amit Grover
CDAC R&D
Gist Group
pune

S. Senthil Kumar19-Oct-05 23:21

S. Senthil Kumar

19-Oct-05 23:21

This code runs fine on my machine

IPHostEntry entry = Dns.Resolve("www.google.com");
Console.WriteLine(entry.AddressList[0].ToString());

Does your computer have a DNS server configured? When you ping www.yahoo.com, do you see the IP Address in the response?

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

A.Grover20-Oct-05 0:25

A.Grover

20-Oct-05 0:25

no i don'nt have DNS server configured on my system. what should i do in order to configure DNS server

Amit Grover
CDAC R&D
Gist Group
pune

leppie20-Oct-05 2:59

leppie

20-Oct-05 2:59

Amit_CDAC_Grover wrote:
no i don'nt have DNS server configured on my system.

^{xacc-ide 0.0.99-preview7 now with C#, C, C++, IL, XML, Nemerle, IronPython, Perl, Caml, SML, Ruby, Flex, Yacc, Java, Javascript, Lua, Prolog and Boo highlighting support!}

Problem with function argument

Dave Kreskowiak20-Oct-05 3:14

Dave Kreskowiak

20-Oct-05 3:14

Open a CMD prompt and type ipconfig /all and see what you get. Down near the bottom of what comes up, it should list at least one DNS Server IP address.

Any DNS setup information has to come from your ISP.

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

faisal khanani19-Oct-05 19:11

faisal khanani

19-Oct-05 19:11

i am working on a project in which i'm dealing with business layer and data layer where business layer has a reference of data layer. when business layer call a function of data layer sending ref object variable as parameter

function signature in data layer is:

"public bool add(ref object objagent)"

this ref object variable is actually an instance of business layer class,
but when i proceed with function assigning values like:

string stragentname;
stragentname=objagent.agentname;

upon complilation it gives me error:"object doesnot contain a definition for agentname"

Matt Gerrans19-Oct-05 19:50

Matt Gerrans

19-Oct-05 19:50

That's because you are passing the thing as an object, instead of whatever type it really is. Your method signature should probably be something like this:

public bool Add( Agent agent )
{
   string agentName = agent.agentName;
   ...
}

From what you've shown, there is no need to have the ref keyword in there.
Also, you don't need Hungarian notation with C#.

Matt Gerrans

faisal khanani19-Oct-05 20:42

faisal khanani

19-Oct-05 20:42

thanks Matt

but i can not declare Agent type in this function, because it is defined in data layer that do not have reference of business layer. therefore, i have to declare object type.

Smile | :)

Guffa19-Oct-05 21:50

19-Oct-05 21:50

If you can't reference the class, then you can't do anything with it (unless you use reflection).

If you don't want the data layer to know the business class, then make an interface with the properties you want to expose, and make the business class implement it, and reference the interface in the data layer.

---
b { font-weight: normal; }