Re: Videos show wrong duration - C# Discussion Boards

create a crypt ing key by text

20-Oct-05 1:35

if (MyAObject is B) ...

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Sasuko20-Oct-05 0:57

Sasuko

20-Oct-05 0:57

i've this string: "abcdefgh"
i want to create a crypting key for the cryptostream, i've tryed ASCII.getBytes("abcdefgh") bu t get error!

Re: create a crypt ing key by text

Guffa20-Oct-05 1:21

Re: create a crypt ing key by text

20-Oct-05 1:21

What kind of error?

That is a very weak key to use for cryptography. Use the crypto provider to create a real key instead.

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Sasuko20-Oct-05 1:42

Sasuko

20-Oct-05 1:42

in this way i get a byte array.
so if i need to give the file to my friend i need to tell him the key.
How if is it just a byte array?

Re: create a crypt ing key by text

Guffa20-Oct-05 2:23

Videos show wrong duration

20-Oct-05 2:23

You can use any representation of the byte data you like. One obvious would be the hexadecimal representation of each byte.

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Sensei7620-Oct-05 0:33

Sensei76

20-Oct-05 0:33

Hello, I need help with the following problem, please.

I am using C# and DirectX 9 to show MPEG-2 video files within a Windows form. Unfortunatelly I often do not get the correct duration of the file when checking the "duration" property, e.g. a 18 second clip assumes to be only 4 seconds long. So all these videos stop playing too early.

Also, it is not possible to jump to certain positions in the video. If I add a new value (e.g. "AverageFrameLength") to the "CurrentPosition" the displayed video proceeds only every n-th frame and skips all frames in between.

I did not have these problems with a MPEG-1 video, for example. With those, everything worked fine.

Does anyone have an idea, why the durations are gathered incorrectly and how I handle this? I searched the whole web for a solution, but it seems nobody else has ever had a problem like this. Frown | :-(

It seems that there are two things that seem have an influence on this situation.

1.) If these video files are converted to use a constant bit rate the duration property seems to get at least get the correct value. Moving from frame to frame still does not work reliably. But as conversion of all files increases their sizes significantly, this ist not an option anyway.

2.) Also, this does not work with every MPEG-2 codec. To receive correct duration values, I first needed to remove the "Moonlight Elecard" MPEG-2 Codec from my system. After that it used another codec automatically. In my case this is the "MPEG-2 Demultiplexer" (Which - I guess - belongs to the DirectX installtion).
Of course, I cannot know what codecs might be installed on a destination system for my application, and even worse, I cannot simply remove a codec from the system just because my app does not like it...

Any ideas?

Re: Videos show wrong duration

Pixinger7720-Oct-05 0:49

Pixinger77

20-Oct-05 0:49

Hello Sensei,

i had similar problems with divx files. It it figures out that the problem depends on the codec configuration. Perhaps this leads you forward D'Oh! | :doh:

Greets Snow

NUMERIC DataGridViewTextBoxColumn

Greeky20-Oct-05 0:27

Greeky

20-Oct-05 0:27

I set Format property of DefaultCellStyle property of an instance of DataGridViewTextBoxColumn to N2 But it doesnt work.

N2 means Numeric 2 digit number (1,254.56 etc)

I aim to create a numeric DataGridViewTextBoxColumn . What can i do else?

Check if users on network

20-Oct-05 0:14

How can i check which users are logged into the network?

marcelw

-- modified at 6:16 Thursday 20th October, 2005

Re: Check if users on network

Dave Kreskowiak20-Oct-05 3:22

Dave Kreskowiak

20-Oct-05 3:22

User don't login to a network, they login to servers. What kind of servers? And from where do you want to determine this information? Client-side or server-side?

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

Re: Check if users on network

Mossie0120-Oct-05 19:50

Mossie01

20-Oct-05 19:50

Basically I want to check if the user is at the office, logged in at his desk. It will need to be an application running on one machine.

marcelw

Re: Check if users on network

Dave Kreskowiak20-Oct-05 22:29

Dave Kreskowiak

20-Oct-05 22:29

That depends on the server your running this from. Are you talking about checking this in a login script, a web service, web application, insert situation here, ...

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

Window Form repaint problem

ppp00119-Oct-05 23:56

ppp001

19-Oct-05 23:56

Hi,

My problem is as below,

1. I open a window form in .NET
2. place a panel A on the form, where the panel's paint method was overrided
3. on the panel A, I placed a tab control
4. on the tab control, I placed another panel B with overrided paint method.

And I repaint all the two panels A and B (by calling its Refresh() method), but only get the panel A refresh, while panel B has no effect.
Why ???? I have tried method like Update(), invalidate(), validate(),
but all have no effect on panel B.

Thanks

c# modem communication

Anil Ch19-Oct-05 23:51

Anil Ch

19-Oct-05 23:51

Hi,
I am using System.IP.Ports namespace to connect to modem from my application.
If I connect to modem(55.6) at 115200 I get message from modem, otherwise(greater or less that 115200) not getting any message from modem.
Can anyone tell me what all setting need to be done using the API for it to accept the connection at other speeds.
Thanks

Re: c# modem communication

javad asadi17-Jan-12 18:35

javad asadi

17-Jan-12 18:35

hi I want the C # application that I can receive faxes through the modem system.
But I do not know how to do this. Please help me
email : javad.asadi@yahoo.com

DBNull.Value to string

Brendan Vogt19-Oct-05 23:43

19-Oct-05 23:43

Hi,

I have the following function that checks a database field for DBNull.Value. If it contains DBNull.Value, the it should return "", otherwise the string.

This is my calling function (objCustomer is an instance of the Customer class):

objCustomer.AddressLine1 = Globals.CheckStringForDBNulls(objDr["Address1"]);

This is my static function:

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

Something tells me that my parameter string strCheckString is of the wrong type.

Please can someone help me correct this error/problem that I am having.

Regards.

-- modified at 5:45 Thursday 20th October, 2005

ZainAMJ20-Oct-05 0:11

20-Oct-05 0:11

ma se wrote:
objCustomer.AddressLine1 = Globals.CheckStringForDBNulls(objDr["Address1"]);

Try This

ma se wrote:
objCustomer.AddressLine1 = Globals.CheckStringForDBNulls(objDr["Address1"].ToString());

======================

ma se wrote:
if(strCheckString.Trim() == DBNull.Value)
return "";
else
return strCheckString.Trim();

TRY THIS

ma se wrote:
if(Convert.IsDBNull(strCheckString.Trim()))
return "";
else
return strCheckString.Trim();

AMJ (With "Z" Factor)

Brendan Vogt20-Oct-05 0:40

20-Oct-05 0:40

Cool and thanks.

ZainAMJ20-Oct-05 0:48

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)

Brendan Vogt20-Oct-05 1:06

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

ZainAMJ20-Oct-05 17:07

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

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)

ZainAMJ20-Oct-05 17:10

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)

Guffa20-Oct-05 1:31

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 />
}

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Brendan Vogt19-Oct-05 23:35