[Message Deleted] - C# Discussion Boards

22-Nov-07 15:02

[Message Deleted]

Re: Cannot read DataSet [modified]

Anthony Mushrow22-Nov-07 15:18

Anthony Mushrow

22-Nov-07 15:18

As a guess, i'd say the problem lies with retreiving the data from another class, especially if the data 'appears' to be loading. So how are you doing that?

My current favourite word is: PIE!

Good ol' pie, it's been a while.

MAW3022-Nov-07 15:50

22-Nov-07 15:50

I just checked to see if the data is there with the following:

//****************all fields below do not show data ***********************
//****************this is from another class ******************************

DataSet dsI = new DataSet("BSD");
DataSet1.BSDDataTable BSD = new DataSet1.BSDDataTable();

int nRecord = BSD[2].nRecNumID;
string strName = BSD[2].strName;
int nSIC = BSD[2].nSIC;

********* Below is the code for loading and is marked where I checked it after loading*******

nUseRecNumID = 0;
//BSD.BeginInit();
//BSD.BeginLoadData();
//BSD.Clear();
Rowset.MoveFirst();
while (!Rowset.IsEOF)
{
if (nUseRecNumID < (Int32)Rowset.GetData(1))
{
// These lines ensure all records are incremented by one and
// RecNumID equals record number.
DataSet1.BSDRow dr = BSD.NewBSDRow();
dr.nRecNumID = nUseRecNumID;
BSD.AddBSDRow(dr);
}
else
{
if (Rowset.GetData(1) != null) nUseRecNumID = (Int32)Rowset.GetData(1);
DataSet1.BSDRow dr = BSD.NewBSDRow();
if (Rowset.GetData(1) != null) dr.nRecNumID = (Int32)Rowset.GetData(1);
if (Rowset.GetData(2) != null) dr.strName = (String)Rowset.GetData(2);
if (Rowset.GetData(3) != null) dr.nSIC = (Int32)Rowset.GetData(3);
BSD.AddBSDRow(dr);
dr.AcceptChanges();
Rowset.MoveNext();
}
nUseRecNumID = nUseRecNumID + 1;
}
//BSD.EndLoadData();
BSD.AcceptChanges();
//dsI.Tables.Add(BSD); //add the table BSD into dataset

//***********************Reads data here****************************
//****************all fields below show data ***********************

int nRecord = BSD[2].nRecNumID;
string strName = BSD[2].strName;
int nSIC = BSD[2].nSIC;

//******************************************************************

-- modified at 0:41 Friday 23rd November, 2007

Vasudevan Deepak Kumar22-Nov-07 18:52

Vasudevan Deepak Kumar

22-Nov-07 18:52

MAW30 wrote:
I continue to get the folowing error "There is no row at position {X}",

What does the DataSet Visualizer of Visual Studio 2005 show during the debugging session?

MAW3022-Nov-07 19:50

22-Nov-07 19:50

What is the DataSet Visualizer?

Michael

Pankaj - Joshi22-Nov-07 19:24

Pankaj - Joshi

22-Nov-07 19:24

This is true you are facing problems....

But what is this..?

"I will give more detail in the email and notes about where the problem is it is a very small sample "

Do you want other will code for you...? This is not fare....

If you have many notes and suppose to send the code then why are you not posting here...?

Regards
Pankaj Joshi

If you want to shape your dreams into reality, please wake-up...

MAW3022-Nov-07 19:31

22-Nov-07 19:31

I am not asking you to code anything for me, only to look it over so you may see everything. There is too much code to post it all, the notes are exactly what I ended up posting anyway. If you would like to look at it I will send you a copy.

Michael

Re: Cannot read DataSet [modified]

Pankaj - Joshi22-Nov-07 19:55

Pankaj - Joshi

22-Nov-07 19:55

I think their is a problem to passing the data between two classes.

Please ensure that you are returning the right dataset from your function and after filling it you won' using the new keyword.

Regards
Pankaj Joshi

If you want to shape your dreams into reality, please wake-up...

MAW3022-Nov-07 20:06

22-Nov-07 20:06

When I remove the new as follows I get the folowing error message:

DataSet dsI;
DataSet1.BSDDataTable BSD;

error message when trying to compile.
"Use of unassigned local variable on BSD"

How do I get around this problem.
Michael

-- modified at 2:38 Friday 23rd November, 2007

So to solve that problem I changed the code to the following:

DataSet1 dsI = new DataSet1(); ( It seems I need to return to this)
DataSet1.BSDDataTable BSD = dsI.BSD; (Object reference not set to an instance of an object)

but I end with the original error "There is no row at position 2"

Catching an Exception

Jeffrey Walton22-Nov-07 14:30

22-Nov-07 14:30

Hi All,

Here I go again Smile | :)

I derived an EncodingException from Exception. In my code, when I catch an OverflowException I throw a new EncodingException. The catch and new-throw executes fine.

However, the code I am trying to guard never catches an exceptions. I've read Jeffrey Richter's chapter on Exceptions in CLR via C#[^]. This behaior is neither expected or documented. The guarded code is below. The EncodingException class will be hung off this thread. Any ideas why no exceptions are being caught?

Thanks,
Jeff

int Eaten = 0;
try
{
  Eaten = TryParseNested(BytesToConsume);
}
catch (EncodingException ex)
{
  // Eat this exception. We are only testing if the
  // the Bit String or Octet String can be parsed.
  // Since we are here, it apparently cannot be parsed.
  // Return -1 to screw up the math. The bad math will be
  // recognised in the caller.
  Debug.Print(ex.Message);

  return -1;
}

catch (OverflowException ex)
{
  Debug.Print(ex.Message);

  return -1;
}

catch( Exception ex)
{
  Debug.Print(ex.Message);

  return -1;
}

Jeffrey Walton22-Nov-07 14:30

Re: Catching an Exception [modified]

22-Nov-07 14:30

[Serializable]
public sealed class EncodingException : Exception, ISerializable
{
  private int _Offset = 0;
  public int Offset
  { get { return _Offset; } }

  public override string Message
  {
    get
    {
      StringBuilder builder = new StringBuilder(base.Message);
      builder.AppendFormat("Illegal encoding encountered at " +
      "Offset {0}{1}", _Offset, Environment.NewLine);
      
      return builder.ToString();
    }
  }

  // Base Class
  public EncodingException() : base() { }
  public EncodingException(String message) : base(message) { }
  public EncodingException(String message, Exception innerException)
    : base(message, innerException) { }

  public EncodingException(int offset) { _Offset = offset; }

  public EncodingException(string message, int offset)
    : this(message) { _Offset = offset; }

  public EncodingException(int offset, Exception innerException)
    : this("", innerException) { _Offset = offset; }

  public EncodingException(string message, int offset, Exception innerException)
    : this(message, innerException) { _Offset = offset; }
  
  // Serialization
  private EncodingException(SerializationInfo info, StreamingContext context)
    : base(info, context)
  {
    _Offset = info.GetInt32("Offset");
  }

  // Allow callers to access state of this object
  [SecurityPermission(SecurityAction.Demand, SerializationFormatter=true)]
  public override void GetObjectData(SerializationInfo info, StreamingContext context)
  {
    base.GetObjectData(info, context);
    info.AddValue("Offset", _Offset);
  }
}

Luc Pattyn22-Nov-07 15:13

Luc Pattyn

22-Nov-07 15:13

forgot to mention: there is a project property (Build/Advanced) to check
OFL/UFL everywhere too.

Smile | :)

-- modified at 21:23 Thursday 22nd November, 2007

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use PRE tags to preserve formatting when showing multi-line code snippets

Jeffrey Walton22-Nov-07 15:46

22-Nov-07 15:46

Hi Luc,

Thanks. It does not matter. This will be my last project with this f***ing language. I am totally disgusted by it's behavior and bugs. It's a damn shame I have so much time into this garbage language for this project.

Here is something else which does not work: take the try wrapper off the Method causing the overflow (it is an int.Parse() method). I check the string length before calling int.Parse. If too long, I throw the EncodingException so that C# never generates it's exception.

Guess what the result is... No catch.

Jeff

Luc Pattyn22-Nov-07 22:42

Luc Pattyn

22-Nov-07 22:42

Hi Jeff,

I am surprised you got such problems with C#. I've done over 100K lines of code in C#
in the last three years, and never had real problems with it. It works fine for me.

If you want my opinion/advice on your Exception problem, please post the relevant pieces
of code. What are the VS and .NET versions you use?

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Luc Pattyn22-Nov-07 14:52

Luc Pattyn

22-Nov-07 14:52

Hi Jeff,

this is what MSDN tells us on OverflowException:

In languages that detect overflow, OverflowException is the exception that gets thrown. For example, in C#, the checked keyword is used to detect overflow conditions. An OverflowException exception occurs only in a checked context.

So by default you get none...

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Jeffrey Walton22-Nov-07 15:12

22-Nov-07 15:12

Hi Luc,

Luc Pattyn wrote:
So by default you get none...

I actually catch it. It's when I throw the EncodingException that the missed catch problem occurs.

I feel like I need an MSDN substciption with this language. There are too many inconsistencies and bugs. I'd like to call Microsoft, place the bug report, and wait for an answer rather than spending hours trying to find my own work arounds.

Jeff

Michael Sync22-Nov-07 15:19

Michael Sync

22-Nov-07 15:19

Jeffrey Walton wrote:
Any ideas why no exceptions are being caught?

If your code has no error then no exception will be caught.

If you want OverflowException exception then try the code below.

short shorty = 32767;           // largest positive short<br />
            int integer = shorty + 1;<br />
            try<br />
            {<br />
                checked                       // force compiler to object<br />
                {<br />
                    shorty = (short)integer;  // try to cram it into a short<br />
                }<br />
            }<br />
            catch ( OverflowException e )<br />
            {<br />
                //"Arithmetic operation resulted in an overflow."<br />
                Console.WriteLine (e.Message);<br />
            }

If you want EncodingException (the custom exception that you created), you have to throw this exp like the example below

int Eaten = 0;<br />
try<br />
{<br />
   throw new EncodingException("this is encoding exception");<br />
}<br />
catch (EncodingException ex)<br />
{<br />
  // Eat this exception. We are only testing if the<br />
  // the Bit String or Octet String can be parsed.<br />
  // Since we are here, it apparently cannot be parsed.<br />
  // Return -1 to screw up the math. The bad math will be<br />
  // recognised in the caller.<br />
  Debug.Print(ex.Message);<br />
<br />
  return -1;<br />
}<br />
<br />
catch (OverflowException ex)<br />
{<br />
  Debug.Print(ex.Message);<br />
<br />
  return -1;<br />
}<br />
<br />
catch( Exception ex)<br />
{<br />
  Debug.Print(ex.Message);<br />
<br />
  return -1;<br />
}<br />

Jeffrey Walton22-Nov-07 16:01