C# Discussion Boards - CodeProject

Re: DBNull.Value to string

Brendan Vogt20-Oct-05 0:40

Brendan Vogt

20-Oct-05 0:40

Cool and thanks.

Re: DBNull.Value to string

ZainAMJ20-Oct-05 0:48

ZainAMJ

20-Oct-05 0:48

if(strCheckString.Trim() == DBNull.Value)
return "";
else
return strCheckString.Trim();

======

This can be reduced to ONE LINE IF STATEMENT Wink | ;)

explore your self and reduce your LOC Cost

AMJ (With "Z" Factor)

Re: DBNull.Value to string

Brendan Vogt20-Oct-05 1:06

Brendan Vogt

20-Oct-05 1:06

If I were to convert a null value coming from a database to something else, would this be good enough? I do not know to what date I should convert if it contains no values, so I chose 1900/01/01. Any ideas?

public static DateTime CheckDateForDBNulls(DateTime dtCheckDate)
{
if(Convert.IsDBNull(dtCheckDate))
return Convert.ToDateTime("1900/01/01");
else
return Convert.ToDateTime(dtCheckDate);
}

Calling function is:

objCustomer.StartDate = Globals.CheckDateForDBNulls(Convert.ToDateTime(objDr["StartDate"])); // Check for DBNull value

I get a horrible error:

Object cannot be cast from DBNull to other types.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidCastException: Object cannot be cast from DBNull to other types.

Please can you help again. Cool | :cool:

-- modified at 7:06 Thursday 20th October, 2005

Re: DBNull.Value to string

ZainAMJ20-Oct-05 17:07

ZainAMJ

20-Oct-05 17:07

objCustomer.StartDate = Globals.CheckDateForDBNulls(Convert.ToDateTime(objDr["StartDate"]));

Instead of implementing this, try this one

objCustomer.StartDate = Globals.CheckDateForDBNulls(objDr["StartDate"].ToString());

==========

In your static function try this

public static DateTime CheckDateForDBNulls(String dtCheckDate)
{
if(Convert.IsDBNull(dtCheckDate) && IsDate(dtCheckDate)==true)
return System.Date.MinValue;
else
return Convert.ToDateTime(dtCheckDate);
}

AMJ (With "Z" Factor)

Re: DBNull.Value to string (Error In That Code)

ZainAMJ20-Oct-05 17:10

ZainAMJ

20-Oct-05 17:10

objCustomer.StartDate = Globals.CheckDateForDBNulls(Convert.ToDateTime(objDr["StartDate"]));

Instead of implementing this, try this one

objCustomer.StartDate = Globals.CheckDateForDBNulls(objDr["StartDate"].ToString());

==========

In your static function try this

public static DateTime CheckDateForDBNulls(String dtCheckDate)
{
if(Convert.IsDBNull(dtCheckDate) || IsDate(dtCheckDate)==false)
return System.Date.MinValue;
else
return Convert.ToDateTime(dtCheckDate);
}

AMJ (With "Z" Factor)

Re: DBNull.Value to string

Guffa20-Oct-05 1:31

Guffa

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; }

String conversion to DBNull.Value

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

Re: String conversion to DBNull.Value

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;

Re: String conversion to DBNull.Value

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.

Re: String conversion to DBNull.Value

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

Re: String conversion to DBNull.Value

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!!

AudioVideoPlayback: Video as texture. Unable to Dispose()

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 | :)

Re: XML File encryption

Guffa19-Oct-05 23:35

Guffa

19-Oct-05 23:35

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

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

Re: XML File encryption

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

Re: XML File encryption

Guffa24-Oct-05 21:24

Guffa

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; }

Re: XML File encryption

rmedo24-Oct-05 22:53

rmedo

24-Oct-05 22:53

Thanks alot for your help

Regarding Resolving IP Address

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

Re: Regarding Resolving IP Address

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!}

Re: Regarding Resolving IP Address

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

Re: Regarding Resolving IP Address

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

Re: Regarding Resolving IP Address

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

Re: Regarding Resolving IP Address

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!}

Re: Regarding Resolving IP Address

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

Problem with function argument

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"

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