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Hi
I am trying to use ICCompress in C# to compress images from a IP camera. Its not going very well im getting this exception:
System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt
The code that causes the exception is,
byte[] outImgData = new byte[outbi.biHeight * outbi.biWidth * (outbi.biBitCount / 8)];
GCHandle pinnedArray = GCHandle.Alloc(outImgData, GCHandleType.Pinned);
IntPtr outImgPtr = pinnedArray.AddrOfPinnedObject();
BitmapData inBmpDat = image.LockBits(
new Rectangle(
0, 0, image.Width, image.Height),
ImageLockMode.ReadOnly, image.PixelFormat);
Avi.ICCompress(compressorHnd,
Avi.AVICOMPRESSF_KEYFRAMES,
ref outbi,
outImgPtr,
ref bi,
inBmpDat.Scan0,
0,
0,
frameNum,
0,
5000,
0,
0);
Im new to importing DLL's so im not to sure if the arguments im using are correct. Can anyone help?
Thanx
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I got a FileSystemWatcher which detect file change,i have encounter a problem with multi-files.
When i create/delete/change SINGLE files the filesystemwatcher would run normally. BUT when i try to copy and paste more than 1 files to the watched destination at the same time,the event will still fired but only fired the first files into listbox.THIS APPLY TO DELETE also if multi-files deletion. ANYONE HAVES CLUES what the code i lack off?
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How to search special character ' (single quote) in Sql server 2005?
For eg.
select Cust_Name from tbl where CustName like '%'%'
Thanks in advance.
modified on Wednesday, April 21, 2010 4:37 AM
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Hi,
After modifying the content in xml file, I tried to save in the same location. It is throwing an exception that the file is already in use. So unable to save in the same location. When I tried to save in the other location, its working fine.
Please guide me to save in the same path. thanks in advance.
string filePath="C:\\test\\sample.xml";
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(filePath);
----------
----------
xmlDoc.Save(filePath);
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try renaming the modified xml document.like original filename + date modified.
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Its like creating a new file. Isn't there a way to replace the file?
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Hi Narvish,
There is no problem with code, the same is worked for me.
i would suggest to make the document object null in finally block.
In your case the worker process might be using the file in memory.
Regards
Surender
No Defeat Is Final Until You Stop Trying!.......
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As per your suggestion, I kept the code in try block and I added
finally
{
xmlDoc = null;
}
Still it is throwing exception that process cannot use that file.. because it is using by other thread. 
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Make sure the file and folder have proper permissions set and file is not kept open anywhere.
remove file manually and try again.
Regards
Surender
No Defeat Is Final Until You Stop Trying!.......
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yes, thats the problem with the file. I copied the file with other name and used it. it worked fine. Thank you
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Hallo can someone please help me, I've got this table:
Valuation Date Construction
30/03/2009 30,625.26
30/04/2009 269,825.04
30/05/2009 850,056.45
30/06/2009 1,922,475.06
30/07/2009 3,500,852.19
30/08/2009 5,757,055.16
30/09/2009 8,699,041.1
30/10/2009 12,232,330.17
30/11/2009 16,612,763.46
30/12/2009 19,166,542.19
30/01/2010 22,098,191.54
28/02/2010 33,539,289.47
30/03/2010 40,518,025
30/04/2010 48,372,377.98
30/05/2010 56,543,248.62
30/06/2010 65,507,314.28
30/07/2010 74,607,415.4
30/08/2010 84,352,063.34
30/09/2010 94,325,187.87
30/10/2010 104,060,459.19
30/11/2010 114,040,884.2
30/12/2010 119,094,482.8
30/01/2011 124,342,210.61
28/02/2011 140,316,539.09
30/03/2011 146,909,564.95
Calculated from this formula:
<br />
public string Calculation(double b, DateTime validation, DateTime start, DateTime end, double alpha, double beta)<br />
{<br />
System.TimeSpan sp_start =<br />
validation.Subtract(start);<br />
string sp_start_str = sp_start.TotalDays.ToString("#");<br />
double t1 = double.Parse(sp_start_str);<br />
<br />
if (validation.Month == 12)<br />
t1 = t1 - 14;<br />
if (validation.Month == 01)<br />
t1 = t1 - 28;<br />
<br />
System.TimeSpan sp_end =<br />
end.Subtract(start);<br />
string sp_end_str = sp_end.TotalDays.ToString("#");<br />
double t2 = double.Parse(sp_end_str);<br />
t2 = t2 - 28;<br />
<br />
double divide = (t1) / (t2);<br />
double minus1 = (1 - (divide));<br />
double pow1 = 1 - (Math.Pow(minus1, alpha));<br />
double calculation = Math.Round(b * (Math.Pow(pow1, beta)), 2);<br />
<br />
return String.Format("{0:#,###,###,###.##}", calculation);<br />
}<br />
What i need to do is:
The first January, all the months following t2 = 28;
After the second January, all the months following t2 = 56;
I probably need to use a for loop??? But not sure how to go about this.
Please someone help!!
Thanks.
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How can i search for some value in a non sorted column of bound datagridview?
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for(int x=0;x<DGV.Rows.Count;x++)
{
if(Val==DGV[COL,x].Value)
{
messageBox.Show("Row="+x);
breake;
}
}
EASY COME EASY GO
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Hello,
i've build a simple server-application, which only needs to hold a TCP-Connection to the client and which listen async for data. This application also do a few tasks for each user....
So i have got a class "UserSession" in which i store the User-Informations and the TCP-Connection. This UserSession runs in a own thread.
My question is now, what's with performance? Is it a problem, that every user has a own Thread? Even if no requests are incoming? The amount of data, which are receiving/sending from this server-application is very low...
I need to handle a lot of user (i don't know how much) this could be 100, 1000 or even 10 000 user...
So, is this a good idea to give each user a own Thread? Or how can i handle such an amount of Users and TCP-Connections very fast?
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excuse me guys...need help here...i'm having a trouble when i deployed my web service.it's giving me an error of "Object Reference not set to an instance of an object". on debug mode,it doesn't give me that error.but when i deploy it to other work station, it gives me that error.i can't trace where the error is coming from.can you help me guys.thanks a lot..
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You need to put in a try-catch block and log the full exception. You will then at least have a chance of spotting where the problem is. Other than that, it's all guess work!
You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace
C/C++ (I dont see a huge difference between them, and the 'benefits' of C++ are questionable, who needs inheritance when you have copy and paste) - fat_boy
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Thank you very much for the reply..but i've already done that but to no avail,i still can't seem to find where the error is coming from..
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Does the exception not give a class and line number?
Normally the Exception.ToString() lists the Exception.StackTrace, which gives this.
You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace
C/C++ (I dont see a huge difference between them, and the 'benefits' of C++ are questionable, who needs inheritance when you have copy and paste) - fat_boy
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thanks a lot for your help.i've found the error...
public int getRequestedFunctionID(string strFunctCode)
{
SQLiteCommand SQLComm;
SQLiteDataReader sqlDR = null;
int intFuncNameID = 0;
string strSQL = "SELECT FuncNameID " +
"FROM tblFuncName WHERE FunctCode = '" + strFunctCode + "'";
try
{
cnn = new SQLiteConnection(strConn);
cnn.Open();
SQLComm = new SQLiteCommand(strSQL, cnn);
sqlDR = SQLComm.ExecuteReader();
sqlDR.Read();
if (sqlDR.HasRows)
{
intFuncNameID = Convert.ToInt32(sqlDR["FuncNameID"]);
}
}
catch
{
intFuncNameID = 100;
}
finally
{
sqlDR.Dispose();
cnn.Close();
}
return intFuncNameID;
}
this is where the error is coming from...can you tell me what's the problem with this code?thanks again...
by the way, i'm calling that function in the main module..like so..
int intFunctID = cProc.getRequestedFunctionID(strFunctCode);
modified on Wednesday, April 21, 2010 4:58 AM
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Ice_Freez05 wrote: what can i do if the function returns a null or 0 value?
Either change the method you are calling, or check for null returns and behave appropriately! 
It is perfectly valid to return a null; many methods do when they have no data to return. It is always worth checking for - there is very little performance overhead, and it saves a lot of hassle for everybody.
Unless the guy who wrote the class didn't mention it in the documentation, in which case: hit him! (Then check for nulls anyway...)
You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace
C/C++ (I dont see a huge difference between them, and the 'benefits' of C++ are questionable, who needs inheritance when you have copy and paste) - fat_boy
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i'm sorry...my mistake...the problem is not the function returning a null or zero value. i've pasted the code above your reply.can you please help me figured out the problem...thanks again..
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Before we get to the problem, a couple of things!
Firstly, when you post a code fragment, use the "code block" wdiget - it preserves teh formatting and makes it easier to read, like this:
public int getRequestedFunctionID(string strFunctCode)
{
SQLiteCommand SQLComm;
SQLiteDataReader sqlDR = null;
int intFuncNameID = 0;
string strSQL = "SELECT FuncNameID " +
"FROM tblFuncName WHERE FunctCode = '" + strFunctCode + "'";
try
{
cnn = new SQLiteConnection(strConn);
cnn.Open();
SQLComm = new SQLiteCommand(strSQL, cnn);
sqlDR = SQLComm.ExecuteReader();
sqlDR.Read();
if (sqlDR.HasRows)
{
intFuncNameID = Convert.ToInt32(sqlDR["FuncNameID"]);
}
}
catch
{
intFuncNameID = 100;
}
finally
{
sqlDR.Dispose();
cnn.Close();
}
return intFuncNameID;
}
Secondly, don't do DB access like that - always use parameterised queries. They help to make the code more readable, and remove the chances for a SQL Injection Attack.
cnn = new SQLiteConnection(strConn);
cnn.Open();
string strSQL = "SELECT FuncNameID FROM tblFuncName WHERE FunctCode = @FC";
SQLComm = new SQLiteCommand(strSQL, cnn);
SQLComm.Parameters.AddWithValue("@FC", strFunctCode);
sqlDR = SQLComm.ExecuteReader();
Thirdly, don't use anonymous exceptions unless you document well why it shoudl be anonymous! Why not? Because when an exception occurs, it is really handy to know why it happened, so that a problem can be averted... At the least, explain why you can ignore the error, if any.
OK, your problem:
There are three ways that the method can return zero:
1) If strFunctCode does not exist in the DB. The reader will then return with no rows, and the value given when intFuncNameID was declared will be returned.
2) If strFunctCode exists in the DB, but has an FuncNameID of zero.
3) If strFunctCode is not what you think it is...
Add some logging: If necessary put
if (intFuncNameID == 0)
{
LogToSomewhereTheDBIfNecessary(strFunctCode, sqlDR["FuncNameID"], "It returns zero!");
}
Immediately before the return statement. (Obviously, that code won't work since sqlDR is out of scope, but you get the general idea...)
You should never use standby on an elephant. It always crashes when you lift the ears. - Mark Wallace
C/C++ (I dont see a huge difference between them, and the 'benefits' of C++ are questionable, who needs inheritance when you have copy and paste) - fat_boy
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thanks a bunch for your help and detailed explanation.;)
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hello every one i am doing a project on jpeg..
please tell me how to free a variable in C#.
please tell me a code which will reinitialize variable value to zero.
or free the memory allocated for a variable just like free() in C.
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