C# Discussion Boards - CodeProject

Scalee5-Dec-07 10:19

5-Dec-07 10:19

I have a dataset filled with names (1 table 1 collumn),
I then loop trough the dataset and add all of them as tree nodes to a treeview.

Then i want to aply a rowfilter after the rowfilter is set i want to loop trough the filtered set,
But evertime i do it nothing gets filtered it just displays everthing in the dataset.

I'm guessing that its my loop but im not sure:

for(int i=0; i < dataset_filter.Tables[0].Rows.Count; i++)

Rowfilter:

dataset_filter.Tables[0].DefaultView.RowFilter = "filter='" + filter.Text + "%'";

Thanks!

Framing JScript Exceptions in C#?

kumar.bs5-Dec-07 10:02

kumar.bs

5-Dec-07 10:02

Hello,

I am executing a JScript class from my C# using Microsoft Jscript Engine, using reflection to invoke JScript.

If there is any exception thrown from JSCript, how to frame it properly for end user. I can handle the execption in try catch block, but i am getting TargetInvocation exception, which needs to be framed properly and shown to end user. Any Inputs in framing the TargetInvocation exception and showing to user in meaningful way?

Thanks

DataGridView DoubleClick Event handler fails when CTRL key is held while DoubleClicking

alanteigne5-Dec-07 10:01

alanteigne

5-Dec-07 10:01

Hello,

I have a DataGridView that is dynamically populated and configured for row select, multiselect = no. When a row is double clicked, an event handler is fired which runs a function based on the Row index. The row index is referenced as follows:

myDgv.SelectedRows[0].Cells[2].Value.ToString()

This works great, until the user is holding the CTRL key while double clicking. I get an "index out of range error", making me think holding the CTRL key changes the value the above code returns.

Has anyone ran into this before? I'm not sure what to do, other than catch the error and fail the event. Any ideas are appreciated!

Thanks,

Alan

Re: DataGridView DoubleClick Event handler fails when CTRL key is held while DoubleClicking

alanteigne6-Dec-07 2:07

alanteigne

6-Dec-07 2:07

I think it may have something to do with the index being cell based rather than row based if I hold CTRL. CTRL modifies selection in Windows (as in selecting multiple files at once, or multiple listbox lines at once).

Re: DataGridView DoubleClick Event handler fails when CTRL key is held while DoubleClicking

alanteigne6-Dec-07 5:24

alanteigne

6-Dec-07 5:24

Ok, figured it out. When I doubleclick on a row while holding CTRL, the dialog selects the row on the first click, but deselects it on the second. The DoubleClick eventhandler fires, references the selected row, and fails as none are selected.

How can I get the call stack of a StackOverflowException?

Dr. Spack5-Dec-07 10:00

Dr. Spack

5-Dec-07 10:00

Hello everyone,

I know this one is a little tricky, but I hope someone has a
hint or an idea.

In our application occurs a StackOverflowException (at least
I think that) and the result is, that the application just
closes.

The problem is that I am not really sure which Exception
occurs because it happens sporadically and only at one of our
customers in different parts of our application.

So I have checked our code what will happens, when I manually
force some unhandled exceptions to occur. For example
NullReference, DivisionByZero, OutOfMemeory. No problem at
all. They all where handled by the Application.ThreadException
event. With a call stack and everything else that is nice to
have.

Then I tried StackOverflowException. The application crashes
and closes with a Dr. Watson hint. No stack trace and no clue
where to start searching.

Does anyone know how to log the call stack of an
StackOverflowException? (Of course without to install Visual
Studio on the customers workstations)

The application is developed in c# @ .Net Framework 2.0

Many thanks for every tip in advance...

modified on Thursday, December 06, 2007 4:55:21 AM

Re: How can I save the call stack of a StackOverflowException?

Robert Royall5-Dec-07 10:50

Robert Royall

5-Dec-07 10:50

According to http://msdn2.microsoft.com/en-us/library/system.stackoverflowexception.aspx[^]...

<br />
In prior versions of the .NET Framework, your application could catch a StackOverflowException object (for example, to recover from unbounded recursion). However, that practice is currently discouraged because significant additional code is required to reliably catch a stack overflow exception and continue program execution.<br />
<br />
Starting with the .NET Framework version 2.0, a StackOverflowException object cannot be caught by a try-catch block and the corresponding process is terminated by default.<br />

Does that help?

Please don't bother me... I'm hacking right now. Don't look at me like that - doesn't anybody remember what "hacking" really means? Sigh | :sigh:

Re: How can I save the call stack of a StackOverflowException?

Dr. Spack5-Dec-07 23:30

Dr. Spack

5-Dec-07 23:30

Thank you, I have also read that and that gave me no hope. So the best is to switch back to Framework 1.0 Laugh | :laugh:

I cannot believe there is no way to catch such a fatal exception.

I have tried to create a new AppDomain…
I have tried to start the whole app in a separate Thread…

But everything I do the application still crashes. Cry | :((

navigating all nodes in a win forms treeview

radi85-Dec-07 8:38

radi8

5-Dec-07 8:38

I am using Treeview in a C# windows form. The data entered into the tree is a hierarchical listing of table definitions associated in groups of various depth off of the Treeview root.

I am looking for a class or routine where I can navigate through each Treeview node and node/child, get the value of the element so i can process the output.

I have a rudimental listing of this through the first 2 nodes (with testing ), but this requires some more elaborate coding, maybe recursive:

<br />
String nodeName = "";<br />
int nodeNum = 0;<br />
int i = 0, j = 1, k=0, cnt=0, lstNode=0;<br />
nodeName = treeView1.ToString();<br />
if (treeView1.Nodes.Count > 0)<br />
{<br />
     for (i = 0; i < treeView1.Nodes.Count; i++)<br />
     {<br />
          nodeName = treeView1.Nodes[i].Text.ToString();<br />
          cnt = treeView1.Nodes[i].GetNodeCount(false);<br />
          if (cnt > 0)<br />
          {<br />
               lstNode = treeView1.Nodes[i].LastNode.Index;<br />
               lstNode = treeView1.Nodes[i].LastNode.Level;<br />
               for (j = 0; j < cnt; j++)<br />
               {<br />
                    try<br />
                    {<br />
                         nodeName = treeView1.Nodes[i].Nodes[j].Text.ToString();<br />
                    }<br />
                    catch (Exception e)<br />
                    { <br />
                         nodeName = "Undefined"; <br />
                    }<br />
               }<br />
          }<br />
     }<br />
}<br />

This needs to be refined so that I can see ALL child elements no matter how deep they are in the Treeview.

Can anyone help?

Re: navigating all nodes in a win forms treeview

Giorgi Dalakishvili5-Dec-07 8:53

Giorgi Dalakishvili

5-Dec-07 8:53

You will need to write a recursive function to iterate through all nodes of a treeview

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Re: navigating all nodes in a win forms treeview

radi85-Dec-07 8:55

radi8

5-Dec-07 8:55

That is my assumption as well, but I have not written a recursive function in quite awhile. Can anyone give me push in the right direction on this? Code samples or what not?

Re: navigating all nodes in a win forms treeview

Pete O'Hanlon5-Dec-07 9:19

Pete O'Hanlon

5-Dec-07 9:19

Without wanting to get into the exact details of the code, it would normally look like this:

public void WalkNode(TreeNode node)
{
  if (node.Nodes != null)
  {
    foreach (Node child in node.Nodes)
    {
       WalkNode(child);
    }
  }
}

Deja View - the feeling that you've seen this post before.

My blog | My articles

Re: navigating all nodes in a win forms treeview

radi86-Dec-07 6:10

radi8

6-Dec-07 6:10

Thank you very much. I was ot looking for the exact details of the code segment, just the outline for now. It has been a long time since doing any recursive programming (avoid like the plague) and am out of practice.

Thanks again. Cool | :cool:

Find name of declaring property of an object

Joby15-Dec-07 8:37

Joby1

5-Dec-07 8:37

Is it possible to find the name of the property for which an instance of an object is assigned to? ie: From inside an instance of an object that is assigned to a property of another object, I want to know the name of the property that that object is assigned to?

For example, you have a "Person" class that has a "MailingAddress" property and a "ShippingAddress" property, with each of these containing a general "Address" class object. From inside the instance of the "Address" object that is assigned to the "ShippingAddress" property, how do I find that this instance is assigned to the "ShippingAddress" property or the "MailingAddress" property? Or more generally, how do I find the name of the property for which an instance of an object is assigned to?

I would like to be able to do this without having a reference to the parent "Person" object; just determine the declaring property's name from any instance of an object.

Ultimately, I would like to define a string that contains the "path" down through an object hierarchy from property to property. For example, create a path string such as: "Person.ShippingAddress.ZipCode", which can be parsed later to in order to set the "ZipCode" property to a specific value for a Person. This example is somewhat trivial, but I need to be able to create this "path" for any object in order to set that object's property values for testing purposes. ie: Given that I know I will start with some parent object (in this case a Person object), I want to parse the path string so I can drill down through the Person class in order to set certain property values and then test the reaction of the program to those newly set values. Having the path string allows me to automate this testing process.

Reflection seems to work well when you want to drill DOWN into a class, but how to you start with an instance of an object and work your way back UP?

Thankyou for your time. Joby

Re: Find name of declaring property of an object

Christian Graus5-Dec-07 9:16

Christian Graus

5-Dec-07 9:16

I forget the details, but it's possible to get a call stack in code, I believe.

Christian Graus - Microsoft MVP - C++

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Re: Find name of declaring property of an object

Pete O'Hanlon5-Dec-07 9:20

Pete O'Hanlon

5-Dec-07 9:20

You could always use the Stack for this. Try looking at the StackFrame class for this.

Deja View - the feeling that you've seen this post before.

My blog | My articles

Wanted to built my own ACD (Auto Call Distribution)

Muhammad Nauman Yousuf5-Dec-07 7:16

Muhammad Nauman Yousuf

5-Dec-07 7:16

I am on my way towards building my own "Automated Call Distribution", IF any has any clue for CTI or TAPI in .net 2.0 please let me know.

Thank you!
M. Nauman Yousuf

"Mess with the Best, Die like the rest"

IO performance in c#

poqeqw5-Dec-07 7:01

poqeqw

5-Dec-07 7:01

Im writing a windows service in c# vs2003 that does a lot of io on file
reading files writeing files and more the problem is
the performance of the program is not so good
1. can some opne direct me to material about io best practices
2. is there free tools to analyse the code so i can track the problematic portion of the code
thanks

Re: IO performance in c#

Ennis Ray Lynch, Jr.5-Dec-07 10:01

Ennis Ray Lynch, Jr.

5-Dec-07 10:01

How are you using the IO? Do you have any code? IO will be slower in a managed context compared to a C memory-mapped file but I have never really had much of a problem with file IO in C#.

Need a C# Consultant? I'm available.

Happiness in intelligent people is the rarest thing I know. -- Ernest Hemingway

Are there in-depth samples for WorkFlow Foundation DependencyProperty ?

vgrigor15-Dec-07 5:27

vgrigor1

5-Dec-07 5:27

I need in-depth WorkFlow Foundation DependencyProperty samples, articles or explanations,
(for creation state workflow , whose activities are connectable to external .NET objects, WinForm's controls, arrays or DataRows in DataTable .)

Are there in-depth samples for DependencyProperty ?

thanks you
_______________________________

something I have:

http://odetocode.com/Blogs/scott/archive/2006/07/27/5444.aspx
DependencyProperty Activity binding

http://www.masteringbiztalk.com/blogs/jon/PermaLink,guid,0fae3e73-7801-4cf6-a5a5-9370b0f99973.aspx

is that the configuration mapping will control what page is next in the flow,

http://blog.hackedbrain.com/articles/UnderstandingDependencyObjectAndDependencyProperty.aspx

Ramblings from a compromised

webbrowser component and web application using java

JackD5-Dec-07 5:15

JackD

5-Dec-07 5:15

I'm trying to run a web application inside a webbrowser component and I get java runtime errors, Those erros doesn't append when running into internet explorer 7.

The c# application I created is simply a window with a webbrowser in it, nothing else.

Jackd

connection error

arkiboys5-Dec-07 4:59

arkiboys

5-Dec-07 4:59

I have installed an application on several xp machines. They all seem to be working fine.
Except one machine which has windows 2000. The application works but it is slow and sometimes it gives the following error:

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

Please note that in sql server 2005 Local and Remote connections is selected using tcpip

Any thoughts why only this machines sometimes gives this error when connecting to the sql server 2005 please?
Thanks

Re: connection error

Dave Kreskowiak5-Dec-07 5:43

Dave Kreskowiak

5-Dec-07 5:43

Try updating the MDAC components to the latest. YOu can get that here[^].

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Passing value types async

Andre Azevedo5-Dec-07 4:15

Andre Azevedo

5-Dec-07 4:15

Hi all,

Can anyone tell me what happens (in the stack context) to the value type "x" after Init() method has been terminated:

--------------------

delegate void TestDelegate(ref int x);

class Program
{

static void Main(string[] args)
{
Init();
Console.WriteLine("Waiting");
Console.Read();
}

static void Init()
{
int x = 123;
int y = 123;
int z = 123;

TestDelegate t = new TestDelegate(TestFunc);
t.BeginInvoke(ref x, null, null);
}

static void TestFunc(ref int x)
{
Thread.Sleep(1000);
Console.WriteLine(x);
}

}

--------------------

Thanks,

________________________________________________________________
There are 10 kind of people: those who knows binary and those who doesn't.

Re: Passing value types async

led mike5-Dec-07 5:17

led mike

5-Dec-07 5:17

It appears you need to do more studying to understand async delegate usage. See if this article helps

sorry, apparently nothing works on the site, here is the URL to the article

http://msdn.microsoft.com/msdnmag/issues/01/08/Async/[^]

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