traversing down the constructors from base class - SystemIndexOuto fRangeException - system.data.dll -there is no row at position 0 ?

[hazz]

My runtime in debug is dropping through the constructors from an upper level
class into subclassed constructors... ..

namespace AB
public class A : MarshalByRefObj ect
public A () //ctor for A
{ System.Diagnost ics.Debug.Write Line(" A ctor - no
; } <-- first stop.
public class B : A
{ public B () } //ctor for B
<-- second stop.

namespace DA
public class DABase : B
{ public DABase() } //ctor for DABase
<-- third stop.

public class AV : DABase, IAV
{
public AV(Token token) //ctor for AV
{
//statement or no statement, result still the same
<-- last stop before exception
} // SystemIndexOuto fRangeException - system.data.dll -there is no
row at position 0
Why system.data?
System.Data is referenced in these projects but why would system.data.dll be
involved in the exception during the downward constructor traversal?
Note: class AV is the class that was called by the client passing a
parameter whose constructor with that signature is never reached.
here is what starts the process - AV m_AV= new AV(tkn);

Thank you for any ideas....?

-Greg

[hazz]

My runtime in debug is dropping through the constructors from an upper level
class into subclassed constructors... ..

namespace AB
public class A : MarshalByRefObj ect
public { A () } //ctor <-- first stop.

public class B : A
{ public B () } //ctor <-- second stop.

namespace DA
public class DABase : B
{ public DABase() } //ctor <-- third stop.

public class AV : DABase, IAV
{
public AV(Token token) //ctor for AV
{ //statement or no statement, result still the same } <-- last stop
before exception
-> SystemIndexOuto fRangeException - system.data.dll -there is no row at
position 0
Why system.data?
System.Data is referenced in these projects but why would system.data.dll be
involved in the exception during the downward constructor traversal?
Note: class AV is the class that was called by the client passing a
parameter whose constructor with that signature is never reached.
here is what starts the process - AV m_AV= new AV(tkn);

Thank you for any ideas. -Greg

[Jon Skeet [C# MVP]]

hazz <ha**@sonic.net > wrote:

My runtime in debug is dropping through the constructors from an
upper level class into subclassed constructors... ..
<snip>
} // SystemIndexOuto fRangeException - system.data.dll -there is no
row at position 0
Why system.data?
System.Data is referenced in these projects but why would system.data.dll be
involved in the exception during the downward constructor traversal?

I suspect it's in the code that you snipped.

Could you post a short but complete program which demonstrates the
problem?

See http://www.pobox.com/~skeet/csharp/complete.html for details of
what I mean by that.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[hazz]

Unhandled Exception: System.IndexOut OfRangeExceptio n: There is no row at
position 0.
at System.Data.Dat aRowCollection. get_Item(Int32 index)
at ServiceControl. MainForm.CheckD ownload_Click(O bject sender, EventArgs
e)
at System.Windows. Forms.Control.O nClick(EventArg s e)
at System.Windows. Forms.Button.On Click(EventArgs e)
at System.Windows. Forms.Button.On MouseUp(MouseEv entArgs mevent)
at System.Windows. Forms.Control.W mMouseUp(Messag e& m, MouseButtons
button, Int32 clicks)
at System.Windows. Forms.Control.W ndProc(Message& m)
at System.Windows. Forms.ButtonBas e.WndProc(Messa ge& m)
at System.Windows. Forms.Button.Wn dProc(Message& m)
at System.Windows. Forms.ControlNa tiveWindow.OnMe ssage(Message& m)
at System.Windows. Forms.ControlNa tiveWindow.WndP roc(Message& m)
at System.Windows. Forms.NativeWin dow.DebuggableC allback(IntPtr hWnd,
Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows. Forms.UnsafeNat iveMethods.Disp atchMessageW(MS G& msg)
at
System.Windows. Forms.Component Manager.System. Windows.Forms.U nsafeNativeMeth o
ds+IMsoComponen tManager.FPushM essageLoop(Int3 2 dwComponentID, Int32 reason,
Int32 pvLoopData)
at System.Windows. Forms.ThreadCon text.RunMessage LoopInner(Int32 reason,
ApplicationCont ext context)
at System.Windows. Forms.ThreadCon text.RunMessage Loop(Int32 reason,
ApplicationCont ext context)
at System.Windows. Forms.Applicati on.Run(Form mainForm)
at ServiceControl. MainForm.Main() The program '[3376] ServiceControl. exe'
has exited with code 0 (0x0).

[Marina]

Yes.

This has nothing to do with constructors.

According to the message, in the CheckDownload_C lick event handler, someone
is trying to get a row out of a datatable.

This is exactly what one would expect, given the message you reported.

"hazz" <ha**@sonic.net > wrote in message
news:eQ******** *****@TK2MSFTNG P10.phx.gbl...

Unhandled Exception: System.IndexOut OfRangeExceptio n: There is no row at
position 0.
at System.Data.Dat aRowCollection. get_Item(Int32 index)
at ServiceControl. MainForm.CheckD ownload_Click(O bject sender, EventArgs
e)
at System.Windows. Forms.Control.O nClick(EventArg s e)
at System.Windows. Forms.Button.On Click(EventArgs e)
at System.Windows. Forms.Button.On MouseUp(MouseEv entArgs mevent)
at System.Windows. Forms.Control.W mMouseUp(Messag e& m, MouseButtons
button, Int32 clicks)
at System.Windows. Forms.Control.W ndProc(Message& m)
at System.Windows. Forms.ButtonBas e.WndProc(Messa ge& m)
at System.Windows. Forms.Button.Wn dProc(Message& m)
at System.Windows. Forms.ControlNa tiveWindow.OnMe ssage(Message& m)
at System.Windows. Forms.ControlNa tiveWindow.WndP roc(Message& m)
at System.Windows. Forms.NativeWin dow.DebuggableC allback(IntPtr hWnd,
Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows. Forms.UnsafeNat iveMethods.Disp atchMessageW(MS G& msg)
at
System.Windows. Forms.Component Manager.System. Windows.Forms.U nsafeNativeMeth o ds+IMsoComponen tManager.FPushM essageLoop(Int3 2 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows. Forms.ThreadCon text.RunMessage LoopInner(Int32 reason,
ApplicationCont ext context)
at System.Windows. Forms.ThreadCon text.RunMessage Loop(Int32 reason,
ApplicationCont ext context)
at System.Windows. Forms.Applicati on.Run(Form mainForm)
at ServiceControl. MainForm.Main() The program '[3376] ServiceControl. exe' has exited with code 0 (0x0).

[hazz]

Thank you Marina. It was an interesting excercise documenting the class
hierachy, whose constructors had just changed significantly.. ..but I
wholeheartedly agree with you after looking at the log. I believe the
exception being thrown was at the callee's entry point when the object was
instantiated.
Appreciatively,
-greg

"Marina" <so*****@nospam .com> wrote in message
news:Ob******** ******@TK2MSFTN GP10.phx.gbl...

Yes.

This has nothing to do with constructors.

According to the message, in the CheckDownload_C lick event handler, someone is trying to get a row out of a datatable.

This is exactly what one would expect, given the message you reported.

"hazz" <ha**@sonic.net > wrote in message
news:eQ******** *****@TK2MSFTNG P10.phx.gbl...

Unhandled Exception: System.IndexOut OfRangeExceptio n: There is no row at
position 0.
at System.Data.Dat aRowCollection. get_Item(Int32 index)
at ServiceControl. MainForm.CheckD ownload_Click(O bject sender, EventArgs e)
at System.Windows. Forms.Control.O nClick(EventArg s e)
at System.Windows. Forms.Button.On Click(EventArgs e)
at System.Windows. Forms.Button.On MouseUp(MouseEv entArgs mevent)
at System.Windows. Forms.Control.W mMouseUp(Messag e& m, MouseButtons
button, Int32 clicks)
at System.Windows. Forms.Control.W ndProc(Message& m)
at System.Windows. Forms.ButtonBas e.WndProc(Messa ge& m)
at System.Windows. Forms.Button.Wn dProc(Message& m)
at System.Windows. Forms.ControlNa tiveWindow.OnMe ssage(Message& m)
at System.Windows. Forms.ControlNa tiveWindow.WndP roc(Message& m)
at System.Windows. Forms.NativeWin dow.DebuggableC allback(IntPtr hWnd,
Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows. Forms.UnsafeNat iveMethods.Disp atchMessageW(MS G& msg) at

System.Windows. Forms.Component Manager.System. Windows.Forms.U nsafeNativeMeth o

ds+IMsoComponen tManager.FPushM essageLoop(Int3 2 dwComponentID, Int32

reason,

Int32 pvLoopData)
at System.Windows. Forms.ThreadCon text.RunMessage LoopInner(Int32 reason, ApplicationCont ext context)
at System.Windows. Forms.ThreadCon text.RunMessage Loop(Int32 reason,
ApplicationCont ext context)
at System.Windows. Forms.Applicati on.Run(Form mainForm)
at ServiceControl. MainForm.Main() The program '[3376]

ServiceControl. exe'

has exited with code 0 (0x0).

[hazz]

Thanks Jon,
Just talking through it and receiving Marina's answer was enough to have me
seek help internally within my company to get at the root. That is the end
of this thread. -greg

"Jon Skeet [C# MVP]" <sk***@pobox.co m> wrote in message
news:MP******** *************** *@msnews.micros oft.com...

hazz <ha**@sonic.net > wrote:

My runtime in debug is dropping through the constructors from an
upper level class into subclassed constructors... ..

<snip>

} // SystemIndexOuto fRangeException - system.data.dll -there is no row at position 0
Why system.data?
System.Data is referenced in these projects but why would system.data.dll be involved in the exception during the downward constructor traversal?

I suspect it's in the code that you snipped.

Could you post a short but complete program which demonstrates the
problem?

See http://www.pobox.com/~skeet/csharp/complete.html for details of
what I mean by that.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too