Noooo! - C# Discussion Boards

Re: Weird C# String Behavior

malharone6-Feb-06 5:29

malharone

6-Feb-06 5:29

This is from ildasm.. we can see "ABC" is inserted twice

//000091: 	string s1 = "ABC";<br />
  IL_0000:  ldstr      "ABC"<br />
  IL_0005:  stloc.0<br />
//000092: 	string s2 = "ABC";<br />
  IL_0006:  ldstr      "ABC"<br />
  IL_000b:  stloc.1<br />
//000093: 	return object.ReferenceEquals(s1, s2);<br />
  IL_000c:  ldloc.0<br />
  IL_000d:  ldloc.1<br />
  IL_000e:  call   bool [mscorlib]System.Object::ReferenceEquals(object, object)<br />
  IL_0013:  stloc.2<br />
  IL_0014:  br.s       IL_0016<br />
//000094: 		}

Re: Weird C# String Behavior

Judah Gabriel Himango6-Feb-06 7:15

Judah Gabriel Himango

6-Feb-06 7:15

The string is most likely interned. Check out my other reply to see if this is the case.

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Connor's Christmas Spectacular!
Judah Himango

Re: Weird C# String Behavior

leppie6-Feb-06 5:16

leppie

6-Feb-06 5:16

It's a compiler optimization Roll eyes | :rolleyes:

xacc.ide-0.1.2.6
New syntax highlight screenshots of xacc.ide

Re: Weird C# String Behavior

malharone6-Feb-06 5:36

malharone

6-Feb-06 5:36

see http://www.codeproject.com/script/comments/forums.asp?forumid=1649&select=1361110&df=100&msg=1361110#xx1361110xx[^]

If compiler optimized it then it'd always return true (compile time optimization) ..but this seems to be runtime "optimization" -- the values are added on stack twice. The link above has the ildasm code.

- Malhar

Re: Weird C# String Behavior

Nish Nishant6-Feb-06 6:06

Nish Nishant

6-Feb-06 6:06

It's due to CLR string interning. See http://blog.voidnish.com/?p=51[^]

Regards,
Nish

My blog : Nish’s thoughts on MFC, C++/CLI and .NET

Re: Weird C# String Behavior

malharone6-Feb-06 6:20

malharone

6-Feb-06 6:20

I agree with you that it is because of string interning. However, in this case, there is no way to distinguish if the two objects are different or not. So for the string class, the Equals and ReferenceEquals have no differentiation -- this is little bit frustrating!!

- Malhar

Re: Weird C# String Behavior

Daniel Grunwald6-Feb-06 6:55

Daniel Grunwald

6-Feb-06 6:55

You can clone a string to get a different instance with the same value.
Or if you use Substring, you will also get a different instance of the same string:
object.ReferenceEquals("Hello", "Hello World".Substring(0,5)) will return false!

Why is this frustrating? The runtime creates interned string instances when the method is JITted. This is much faster than creating the string instance everytime the method in run. If you want a new string instance every time, well, then you still can use Clone().

Noooo!

leppie6-Feb-06 7:49

leppie

6-Feb-06 7:49

Its just a compiler optimization, called constant folding. From the IL you can clearly see the same string reference has been assigned from the string table.

<FONT color=DarkBlue>.method</FONT> <FONT color=DarkGreen>/*06000001*/</FONT> <FONT color=Blue>private hidebysig static</FONT>
        <FONT color=Blue>void</FONT>  Main(<FONT color=Blue>string</FONT><FONT color=DarkBlue>[]</FONT> args) <FONT color=Blue>cil managed</FONT>
<FONT color=DarkGreen>// SIG: 00 01 01 1D 0E</FONT>
{
  <FONT color=DarkBlue>.entrypoint</FONT>
  <FONT color=DarkGreen>// Method begins at RVA 0x2050</FONT>
  <FONT color=DarkGreen>// Code size       31 (0x1f)</FONT>
  <FONT color=DarkBlue>.maxstack</FONT>  <FONT color=Red>2</FONT>
  <FONT color=DarkBlue>.locals</FONT> <FONT color=DarkGreen>/*11000001*/</FONT> <FONT color=Blue>init</FONT> (<FONT color=Blue>string</FONT> V_0<FONT color=DarkBlue>,</FONT>
           <FONT color=Blue>string</FONT> V_1)
  <FONT color=DimGray>IL_0000:</FONT>  <FONT color=DarkGreen>/* 72   | (70)000001       */</FONT> <FONT color=DeepPink>ldstr</FONT>      <FONT color=Maroon>"ABC"</FONT> <FONT color=DarkGreen>/* 70000001 */</FONT>
  <FONT color=DimGray>IL_0005:</FONT>  <FONT color=DarkGreen>/* 0A   |                  */</FONT> <FONT color=DeepPink>stloc.0</FONT>
  <FONT color=DimGray>IL_0006:</FONT>  <FONT color=DarkGreen>/* 72   | (70)000001       */</FONT> <FONT color=DeepPink>ldstr</FONT>      <FONT color=Maroon>"ABC"</FONT> <FONT color=DarkGreen>/* 70000001 */</FONT>
  <FONT color=DimGray>IL_000b:</FONT>  <FONT color=DarkGreen>/* 0B   |                  */</FONT> <FONT color=DeepPink>stloc.1</FONT>
  <FONT color=DimGray>IL_000c:</FONT>  <FONT color=DarkGreen>/* 06   |                  */</FONT> <FONT color=DeepPink>ldloc.0</FONT>
  <FONT color=DimGray>IL_000d:</FONT>  <FONT color=DarkGreen>/* 07   |                  */</FONT> <FONT color=DeepPink>ldloc.1</FONT>
  <FONT color=DimGray>IL_000e:</FONT>  <FONT color=DarkGreen>/* 28   | (0A)000002       */</FONT> <FONT color=DeepPink>call</FONT>       <FONT color=Blue>bool</FONT> <FONT color=DarkBlue>[</FONT>mscorlib<FONT color=DarkGreen>/* 23000001 */</FONT><FONT color=DarkBlue>]</FONT>System.Object<FONT color=DarkGreen>/* 01000001 */</FONT>::ReferenceEquals(<FONT color=Blue>object</FONT><FONT color=DarkBlue>,</FONT>
                                                                                                                               <FONT color=Blue>object</FONT>) <FONT color=DarkGreen>/* 0A000002 */</FONT>
  <FONT color=DimGray>IL_0013:</FONT>  <FONT color=DarkGreen>/* 28   | (0A)000003       */</FONT> <FONT color=DeepPink>call</FONT>       <FONT color=Blue>void</FONT> <FONT color=DarkBlue>[</FONT>mscorlib<FONT color=DarkGreen>/* 23000001 */</FONT><FONT color=DarkBlue>]</FONT>System.Console<FONT color=DarkGreen>/* 01000003 */</FONT>::WriteLine(<FONT color=Blue>bool</FONT>) <FONT color=DarkGreen>/* 0A000003 */</FONT>
  <FONT color=DimGray>IL_0018:</FONT>  <FONT color=DarkGreen>/* 28   | (0A)000004       */</FONT> <FONT color=DeepPink>call</FONT>       <FONT color=Blue>string</FONT> <FONT color=DarkBlue>[</FONT>mscorlib<FONT color=DarkGreen>/* 23000001 */</FONT><FONT color=DarkBlue>]</FONT>System.Console<FONT color=DarkGreen>/* 01000003 */</FONT>::ReadLine() <FONT color=DarkGreen>/* 0A000004 */</FONT>
  <FONT color=DimGray>IL_001d:</FONT>  <FONT color=DarkGreen>/* 26   |                  */</FONT> <FONT color=DeepPink>pop</FONT>
  <FONT color=DimGray>IL_001e:</FONT>  <FONT color=DarkGreen>/* 2A   |                  */</FONT> <FONT color=DeepPink>ret</FONT>
} <FONT color=DarkGreen>// end of method Class1::Main</FONT>

xacc.ide-0.1.2.6
New syntax highlight screenshots of xacc.ide

Wierdness trying to use a class library in a service

ByStorm Software6-Feb-06 4:22

ByStorm Software

6-Feb-06 4:22

I'm written a crazy simple service in C# and a simple class library that exposes 1 class. We're talking "hello world" simple here.

Here's the wierdness.
I have a reference to the class library from the service, when I attempt to start the service, I get an event log entry saying that it can't find the class library.

Event log record-->
Service cannot be started. System.IO.FileNotFoundException: Could not load file or assembly 'SampleClass, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.
File name: 'SampleClass, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'
at RemotingTest.TestService.OnStart(String[] args)
at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)

What I've tried.
Create a console app using the same code -> Works
Remove the calls to the class library and start the service -> Works
uninstall the service/reinstall the service and start the service -> Fails.
Copy the class library dll to the windows system32 directory -> Fails.

????

Any ideas? I'm sure that it is something really stupid, but I can't think of it.

Re: Wierdness trying to use a class library in a service

Joe Woodbury6-Feb-06 4:54

Joe Woodbury

6-Feb-06 4:54

I suspect it has to do with security rights.

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

Re: Wierdness trying to use a class library in a service

leppie6-Feb-06 7:57

leppie

6-Feb-06 7:57

Use the FusionLogViewer, that should help you see where the assembly is being looked for. Failing that, you can use a tool called FileMon from SysInternals to see what is actually requested.

xacc.ide-0.1.2.6
New syntax highlight screenshots of xacc.ide

Re: Wierdness trying to use a class library in a service

ByStorm Software6-Feb-06 9:48

ByStorm Software

6-Feb-06 9:48

I forgot all about Filemon...it showed me the error in my ways...., the service was looking for the class library in the obj\debug\ folder instead of the bin\debug folder which is where I put the dll. I still don't know why it didn't work when I put it in the system32 folder.

but at least I'm up and running....for now. <hehe>

thanks all.

XsltArgumentList doesn't accept long parameter values

mikko laanti6-Feb-06 4:21

mikko laanti

6-Feb-06 4:21

I have problems passing parameters from C# application to XSL file and doing a transformation.
My code is below.:

XsltArgumentList xslArg = new XsltArgumentList();

String key = "grandpa/father/son"; // This is the name of node I want pass and gets it value
xslArg.AddParam("xslParam", "", key);

// Create the XslTransform and load the stylesheet.
XslTransform xslt = new XslTransform();
xslt.Load(stylesheet); // xsl stylesheet

XmlUrlResolver xmlUrlResolver = new XmlUrlResolver();

// Output to console.
XmlTextWriter writer = new XmlTextWriter(Console.Out);

// Transform the xml file
xslt.Transform(new XPathDocument(filename), xslArg, writer, xmlUrlResolver);

writer.Close();

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

XSL file looks like this

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:param name="xslParam"/>
<xsl:template match="/">
<alku><xsl:value-of select="$xslParam"/></alku>
</xsl:template>
</xsl:stylesheet>

The problem is that node grandpa/father/son is not executed! It's passed to XSL file
but XslTransform classes transsform method does not fetch it's value from xml file.
It only shows the key value in console. Node grandpa/father/son has value in it's
xml file.

So, am I missing something or is there a bug in XsltArgumentList and it's transformation.

Has anyone any ideas what could be wrong?

Cheers!

Re: XsltArgumentList doesn't accept long parameter values

leppie6-Feb-06 5:21

leppie

6-Feb-06 5:21

mikko laanti wrote:
Has anyone any ideas what could be wrong?

Maybe an XML namespace issue? I recall XPath is dodgey on default namespaces, you have to create a dummy alias for it. Perhaps the same issue?

xacc.ide-0.1.2.6
New syntax highlight screenshots of xacc.ide

Add to favourites

Brendan Vogt6-Feb-06 3:51

Brendan Vogt

6-Feb-06 3:51

I have a link on my webpage, when clicked upon it takes the user to a page where the website's home page is added to the favourites. Can someone please tell me where to go and look for this on MSDN. I would like to do it through C#. And also, maybe create a directory in My Favourites, and save the link in this directory.

Regards
ma se

status bar

Kola Sokol6-Feb-06 3:41

Kola Sokol

6-Feb-06 3:41

hi, how can i create a nice look status bar in c# 2005?
how i can change look status bar?

Thx for your help.

-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
Athlon 64 3500+, Gigabyte GA-K8NXP-9, 2x512 DDR400 Kingston, Inno3d 6200 PCIe, SS2 B2C2 v2.6, HDD := 450gb, Genius 56k int, NEC DVD-RW и мать его Суньмастер 550.

Re: status bar

Ravi Bhavnani6-Feb-06 4:04

Ravi Bhavnani

6-Feb-06 4:04

Use a StatusStrip[^] control.

/ravi

My new year's resolution: 2048 x 1536
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com

Re: status bar

Kola Sokol6-Feb-06 5:06

Kola Sokol

6-Feb-06 5:06

ok thanks.
realy nice Wink | ;)

-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
Athlon 64 3500+, Gigabyte GA-K8NXP-9, 2x512 DDR400 Kingston, Inno3d 6200 PCIe, SS2 B2C2 v2.6, HDD := 450gb, Genius 56k int, NEC DVD-RW и мать его Суньмастер 550.

memcopy in C# ?

smoitry6-Feb-06 3:28

smoitry

6-Feb-06 3:28

Hi,

I've got a problem I can't solve, maybe I did the wrong searches on google for that !

I have some short and int values I want to put one behind the other in an existing byte array. In C++ i would have done a memcopy for each value passing the pointer to the byte array position I needed. Then, for reading, I would have done something like
int i = (int)b[3];

Now I have to do that in C#, and if possible using a way that would be as fast as the C++ way ... How can I do that ?

Thanks !

Stéphane

Re: memcopy in C# ?

Judah Gabriel Himango6-Feb-06 4:58

Judah Gabriel Himango

6-Feb-06 4:58

Although it's typically not recommended, you can still use pointers in C#. See the C# corner article on pointers[^].

As far as copying goes, you can use Array.Copy, or manually iterate over and populate using a for loop or a foreach loop.

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Connor's Christmas Spectacular!
Judah Himango

Help with multiview control needed!!

BenPage6-Feb-06 2:07

BenPage

6-Feb-06 2:07

Hi there..

I wish to create a mutiview control and then want to dynamically add view cotrols to it while the webpage is displayed. The problem is that when I do this and run my webform, I get the following error:

ActiveViewIndex is being set to '0'. It must be smaller than the current number of View controls '0'. For dynamically added views, make sure they are added before or in Page_PreInit event.

I did create the view controls in the Page_Load() function and then added them to the Views property of the multiview Cotrol object..

How can I fix this...

Thank u!!

bit + sq

ita_cas6-Feb-06 1:48

ita_cas

6-Feb-06 1:48

I have an sql table which one of its column data type is bit
How can I update it from c# app ?
Thanks

Re: bit + sq

albCode6-Feb-06 2:01

albCode

6-Feb-06 2:01

example

update tablename set columnbitvalue = 1 where idcolumn = 21;

same as

update tablename set columnbitvalue = '1' where idcolumn = 21;

you can update column which contain bit or integer giving update command as string, but u base in ur id for selected row which u want to update

combo box, datagrid problem

steve1_rm20006-Feb-06 1:31

steve1_rm2000

6-Feb-06 1:31

Hello,

When l change the value of the combo box, as soon as the combo box loses focus the value will change to the value it was before. The new value does not remain. Has this got something to do with the edit options of the datagrid. I am not sure.

The only way l have solved this problem is to save the new value to the database, and then fill the datagrid from database again with the new. This has to be done everytime the user changes the combo box value.

The way l would like this to work is for the user to change the values in the combo boxes, and have the value remain. When they have finished, they can save everything to the database.

I hope you can help me with this project again. I have the code below that inserts the combo box into the datagrid.

<br />
if ( !this.grdCustomerProducts.TableStyles.Contains("Product") )<br />
					{<br />
						DataGridTableStyle grdTblStyle = new DataGridTableStyle();<br />
						grdTblStyle.MappingName = dt.TableName;<br />
						grdCustomerProducts.TableStyles.Add(grdTblStyle);<br />
<br />
						GridColumnStylesCollection colStyle;<br />
						colStyle = grdCustomerProducts.TableStyles["Product"].GridColumnStyles;<br />
						colStyle[0].Width = 150;<br />
				<br />
						DataGridTextBoxColumn dgtb = (DataGridTextBoxColumn)grdCustomerProducts.TableStyles["Product"].GridColumnStyles[2];<br />
						dgtb.TextBox.Controls.Add(cmbQuantities);<br />
					}<br />

Thanks for you help in advance,

Steve

How to create RadioButtonColumn for DataGridView

USrinivas6-Feb-06 1:17

USrinivas

6-Feb-06 1:17

Hi,
I need a DataGridViewColumn With Radiobuttons like CheckBoxColumn in my application.

Immediate help will be appreciated

Srinivas

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