Never mind - Figured it out - C# Discussion Boards

Calling a function by it's name which has been stored in a string

Gareth_Hastings20-Apr-05 4:37

20-Apr-05 4:37

Hello,

I've found in every function I am writing I have lots of debug code and was just wondering if I can somehow shorten it. For example:

<br />
void testFunction()<br />
{<br />
  try<br />
  {<br />
    ....<br />
    Do something that might cause an exception here<br />
  }<br />
  catch(mySpecialException e)<br />
  {<br />
    myLogClass.log(e.message);<br />
    myLogClass.dump;  //dumps systeminfo to somewhere<br />
  }<br />
}<br />

What I would like is to have some kind of wrapper which I could pass the function name (either by name or as a pointer(delegate?)) to it which would then execute and return.

Example:

<br />
void wrapper(functionToRun())<br />
{<br />
  try<br />
  {<br />
    functionToRun();<br />
  }<br />
  catch(...)<br />
  {<br />
    myLogClass.log(message);<br />
  }<br />
}<br />
<br />
void test()<br />
{<br />
  Console.WriteLine("Hello this is a test!");<br />
}<br />
<br />
void hello()<br />
{<br />
  Console.WriteLine("Hello");<br />
}<br />
<br />
static void Main(string[] args)<br />
{<br />
  wrapper(test());<br />
  wrapper(hello());<br />
}<br />

Any ideas?

Thanks

Re: Calling a function by it's name which has been stored in a string

S. Senthil Kumar20-Apr-05 4:52

S. Senthil Kumar

20-Apr-05 4:52

If all your functions have the same signature, then it is possible. You can do something like

public class Foo
{
    delegate void WrapperDelegate();

    void Hello() { Console.WriteLine("Hello"); }
    void Test() { Console.WriteLine("Test"); }

    public void SomeFunc()
    {
       executeFunction(new WrapperDelegate(Hello));
       executeFunction(new WrapperDelegate(Test));
    }

    private void executeFunction(WrapperDelegate d)
    {
        try
        {
           d();
        }
        catch(Exception e)
        {
           // blah blah
        }
    }
}

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: Calling a function by it's name which has been stored in a string

Gareth_Hastings20-Apr-05 5:06

Gareth_Hastings

20-Apr-05 5:06

Thanks for the suggestion but unfortunately hardly any of my functions have the same signature!

Re: Calling a function by it's name which has been stored in a string

S. Senthil Kumar20-Apr-05 5:54

S. Senthil Kumar

20-Apr-05 5:54

The solution will work if there only a few signatures. You just need to create one WrapperDelegate for each type and add one executeFunction for each such WrapperDelegate.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Constructing Delegate from Object and Method ptr

Tristan Rhodes20-Apr-05 3:55

Tristan Rhodes

20-Apr-05 3:55

I'm trying to construct a delegate manualy, at runtime, from an object refference, and a pointer to a method's runtime handle. However, when i try and compile to code :

<br />
System.Windows.Forms.TreeViewEventHandler thing<br />
	= new System.Windows.Forms.TreeViewEventHandler(obj, ip);<br />

It throws an error message saying - "Method Name Expected"

How can I get around this?

regards

Cata

Re: Constructing Delegate from Object and Method ptr

leppie20-Apr-05 4:05

leppie

20-Apr-05 4:05

You cant do that. Pass object.MethodName. Else if that info is not available, use reflection to construct a delegate.

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Re: Constructing Delegate from Object and Method ptr

Tristan Rhodes20-Apr-05 4:39

Tristan Rhodes

20-Apr-05 4:39

Cheers, got to it about 10 seconds after u posted Big Grin | :-D

Never mind - Figured it out

Tristan Rhodes20-Apr-05 4:34

Tristan Rhodes

20-Apr-05 4:34

It seemst that VS.net doesn't like me running away on my own with delegates. So i just reflected it.

If anyone is interested - Here is the code (Exception Handling omitted for ease of reading):

<br />
		/// <summary><br />
		/// Invoke a delegate via reflection<br />
		/// </summary><br />
		/// <param name="delegateType">Type of the delegate to construct</param><br />
		/// <param name="obj">The object to construct the delegate from. (Can be null<br />
		/// for static methods)</param><br />
		/// <param name="method">The method on the object to use as a delegate</param><br />
		/// <returns>The constructed delegate, or null if there was an error in<br />
		/// instantiation.</returns><br />
		public static object InvokeDelegateViaReflection(Type delegateType, object obj, MethodInfo method)<br />
		{<br />
			//Locate constructor method<br />
			ConstructorInfo ci = delegateType.GetConstructors()[0];<br />
<br />
			//Construct arguments<br />
			object[] args = new object[]{@obj, method.MethodHandle.GetFunctionPointer()};<br />
<br />
			//Call constructor<br />
			object result = ci.Invoke(<br />
				BindingFlags.Public | BindingFlags.Static | BindingFlags.CreateInstance,<br />
				null,args,null);	<br />
<br />
			//return new delegate<br />
			return result;<br />
		}<br />

Hope that helps someone

Cata

Re: Never mind - Figured it out

leppie20-Apr-05 8:51

leppie

20-Apr-05 8:51

Cool, I didnt actually suggested that Smile | :)

I was thing along the lines of Delegate.CreateDelegate(Type, Object, String) : Delegate, but you method is perhaps 'stricter' Smile | :)

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IDREES

idreesbadshah20-Apr-05 3:41

idreesbadshah

20-Apr-05 3:41

source code for voice chating on LAN using C#

Re: IDREES

Colin Angus Mackay20-Apr-05 3:52

Colin Angus Mackay

20-Apr-05 3:52

And your question is???

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Re: IDREES

DavidNohejl20-Apr-05 4:41

DavidNohejl

20-Apr-05 4:41

Colin Angus Mackay wrote:
And your question is???
As usual...

Give me "source code for voice chating on LAN using C# "

Smile | :)

or maybe

David

Never forget: "Stay kul and happy" (I.A.)

David's thoughts / dnhsoftware.org / MyHTMLTidy

Re: IDREES

Colin Angus Mackay20-Apr-05 4:45

Colin Angus Mackay

20-Apr-05 4:45

Why does everyone want to do chat applications?!

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Re: IDREES

Anonymous21-Apr-05 4:09

Anonymous

21-Apr-05 4:09

I have requested Source code or any help or logic for
voice communication over LAN.thanks for help.but i m sorry i cannot understand mentioned website or i cannot get source code.please help me an give more information

THANKX

Re: IDREES

Colin Angus Mackay21-Apr-05 4:20

Colin Angus Mackay

21-Apr-05 4:20

Anonymous wrote:
i cannot understand mentioned website or i cannot get source code

Nobody mentioned a web site.

No one was able to help. This could be for a number of reasons.

1. No one here has experience of writing voice chatting programs

2. There are experienced people here, but the answer would be long and complex and most people don't have that much time.

3. Your request is too vague.

Questions that generate good answers are generally very specific and do not ask for a whole system.

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Problem with .NET 2 Beta 2 (C# Express Beta 2)

Jucs20-Apr-05 3:31

Jucs

20-Apr-05 3:31

I am using .NET Beta 2 now I have a big problem - all my apps exit after some minute without any comment. If I run them in debug mode, I get this in the output window:

The program '[5704] test.exe: Managed' has exited with code -1073741819 (0xc0000005).

Do you know what the problem could be?

Thanks Smile | :)

/Edit:

I know now that this occours if a remote machine disconnects "unnormally" from the application.

If I, for instance, connect to test.exe with some program and then kill the connecting program... then test.exe will disappear...

Re: Problem with .NET 2 Beta 2 (C# Express Beta 2)

Robert M. Bouwens20-Apr-05 5:14

Robert M. Bouwens

20-Apr-05 5:14

Hi,

actually, it should be Lo...

Try to load a form.
On my pc I get a package load error.
If I try to run it, the beta 2 'stuff' just crashes...

Robert

Problem with StreamReader.BaseStream.Position

AfzalHassen20-Apr-05 3:27

AfzalHassen

20-Apr-05 3:27

Hi,

Heres an example of what i am doing now...

line 01 RECORD 1 ,RECORD 2 ,RECORD 3
line 02 data,data,data
line 03 data, ,data
line 04 data,data,data
line 05 RECORD 4 ,RECORD 5 ,RECORD 6
line 06 data,data,data
line 07 data,data,data
line 08 ,data,
line 09 data, ,data
line 10 RECORD 4 ,RECORD 5 ,RECORD 6
line 11 data,data,data
line 12 data, ,data
line 13 data,data,data

I am iterating through the file line by line, because the data between the blocks of records are inconsistent, i'm using regular expresion to test for the begining of the next record so that i know what data to process. the problem is that the method that is making use of this piece of code is required to return only 1 record at any one time. i have managed to solve the 1 record at a time issue by keeping track of the records that were returned and then following a few other steps.

Because I'm testing for the beginning of the next record, the StreamReader will alwaus pass the point at which I need to be in order to read the next block of records that I need to process. i.e line
I have tried moving the position of the base stream to less than to where/what it currently is by doing the following..

_myFile.BaseStream.Position = _myFile.BaseStream.Position - _previousLineData.Length;
but this doesn't work Frown | :(

In addition, both overloads of the Peek() method of the StreamReader are of no use to me (since they only peek for characters without advancing the StreamReader) and i need to read the whole line to test the RegEx in order to determine whether i have reached the end of a block of records.

as can be seen by the generic sample of the file data above, the data in the file is not well organised and or managed.

any help/hints and advice will be much appreciated..

Thanks a million
Afzal Hassen

How to add flash into C# applications?

Alper Camel20-Apr-05 3:20

Alper Camel

20-Apr-05 3:20

I want to add flash (swf) into my application
for example flash buttons..etc..

How can I do that?

Autocomplete/intellisence in a multiline edit box

djkno320-Apr-05 2:28

djkno3

20-Apr-05 2:28

Does anyone know how to do this? I'm trying to make a source code editing program and I would like intellisence/autocomplete intregrated into it. I have looked at the shell extensions example here and it will only work with the first word you type. The .net 2.0 Express beta only had auto complete for single lines (and only the first letter as well).

I just had an idea to put the currently typed(ing) word into a buffer and use autocomplete on that. Can anyone think of a better way?

Re: Autocomplete/intellisence in a multiline edit box

Ashok Dhamija20-Apr-05 17:41

Ashok Dhamija

20-Apr-05 17:41

You can have a look at this project[^]), where similar features are available in the source-code editor.

Re: Autocomplete/intellisence in a multiline edit box

djkno321-Apr-05 10:08

djkno3

21-Apr-05 10:08

gah, I feel so dumb Wink | ;)

I never even thought of that Wink | ;)

Windows Forms - Programmatically scroll a listview control to the selected item

abcxyz8220-Apr-05 2:15

abcxyz82

20-Apr-05 2:15

Hi all,

I am writing simple windows form application with VS.NET 2003, It loads images selected from Openfiledialog in Listview its fine but How can I get listview to scroll to the selected item.

Regards.
Maulikce

Re: Windows Forms - Programmatically scroll a listview control to the selected item

Dave Kreskowiak20-Apr-05 5:56

Dave Kreskowiak

20-Apr-05 5:56

Easy - ListView1.Items(Index).EnsureVisible(); or myListViewItem.EnsureVisible();

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

How to extract the sql query from a report

Ana-Gabriela Clem20-Apr-05 1:52

Ana-Gabriela Clem

20-Apr-05 1:52

Please help me,I want to extract the sql query from a report in C# and after I modify the sql, the report change after the new sql.
Thanks.

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