C# Discussion Boards - CodeProject

Meysam Mahfouzi3-Aug-03 16:54

3-Aug-03 16:54

James T. Johnson wrote:
lock(al_A.SyncRoot){ foreach(object a in al_A) { lock(a) { // use a } }}

But by using above code, as I understand, every object in ArrayList al_A is locked and released one after another. What I want is locking all of them at the same time. Is below code the solution for me?

foreach(<code>Object </code>o in al_A)
        Monitor.Enter(<code>o</code>);

...

foreach(<code>Object </code>o in al_A)
        Monitor.Exit(<code>o</code>);

Don't forget, that's

Persian Gulf

not Arabian gulf!

Re: Lock problem

James T. Johnson3-Aug-03 17:01

James T. Johnson

3-Aug-03 17:01

Meisi wrote:
But by using above code, as I understand, every object in ArrayList al_A is locked and released one after another.

Correct

Meisi wrote:
What I want is locking all of them at the same time. Is below code the solution for me?

Yes, that would do it.

James

"I despise the city and much prefer being where a traffic jam means a line-up at McDonald's"
Me when telling a friend why I wouldn't want to live with him

How do I supress the Expect: 100-continue header from being sent with a HttpWebRequest Post?

Furty2-Aug-03 19:43

Furty

2-Aug-03 19:43

I've hit a brick wall with this one..

I'm trying to perform a HttpWebRequest that posts form data to the target server - the problem is that the request *always* contains an Expect: 100-continue header, which on HTTP 1.0 servers results in a 500 error.

None of these seemingly obvious fixes work:

Set the HttpWebRequest.Expect property to null or String.Empty
Set the HttpWebRequest.ProtocolVersion to HttpVersion.Version10

Note that my class works perfectly with HTTP 1.1 servers, so I doubt there's anything I've done incorrectly in code. Also note that the problem only surfaces when you POST data to the server with the request, no post data = no problem.

Searching google for this problem has given me a couple of people that have hit the same problem, but not one valid workaround.

Help!

Read and write in .INF file

Hoang Dung2-Aug-03 16:59

Hoang Dung

2-Aug-03 16:59

Hi,
Howto I can read and write section in .INF file with C#?
Please help me.

Thanks.
H.Dung.

Re: Read and write in .INF file

Furty3-Aug-03 17:41

Furty

3-Aug-03 17:41

One of these links may help:

http://www.gotdotnet.com/Community/UserSamples/Details.aspx?SampleGuid=be6819e9-66a0-4524-abf9-09d5ff99e88c[^]

http://www.gotdotnet.com/Community/UserSamples/Details.aspx?SampleGuid=d10f0003-37ef-4427-9a85-74db5ceb547a[^]

VB6/VB.NET Case Is < 0 in c# ???

Chua Wen Ching2-Aug-03 14:49

Chua Wen Ching

2-Aug-03 14:49

Hi there. I need some help here.

I am trying to convert a sample application for learning purposes. But i am stuck to see this:

Select Case ShipPitchSM
Case Is > 0
ShipPitchSM = ShipPitchSM - Friction
If ShipPitchSM < 0 Then ShipPitchSM = 0
If ShipPitchSM > 0.03 Then ShipPitchSM = 0.03
Case Is < 0
ShipPitchSM = ShipPitchSM + Friction
If ShipPitchSM > 0 Then ShipPitchSM = 0
If ShipPitchSM < -0.03 Then ShipPitchSM = -0.03
End Select

Select Case ShipYawSM
Case Is > 0
ShipYawSM = ShipYawSM - Friction
If ShipYawSM < 0 Then ShipYawSM = 0
If ShipYawSM > 0.03 Then ShipYawSM = 0.03
Case Is < 0
ShipYawSM = ShipYawSM + Friction
If ShipYawSM > 0 Then ShipYawSM = 0
If ShipYawSM < -0.03 Then ShipYawSM = -0.03
End Select

Select Case ShipRollSM
Case Is > 0
ShipRollSM = ShipRollSM - Friction
If ShipRollSM < 0 Then ShipRollSM = 0
If ShipRollSM > 0.03 Then ShipRollSM = 0.03
Case Is < 0
ShipRollSM = ShipRollSM + Friction
If ShipRollSM > 0 Then ShipRollSM = 0
If ShipRollSM < -0.03 Then ShipRollSM = -0.03
End Select

Any help?

How do you code that in c#? I try my best to place conditions in case statements, but compile errors.

Thanks.

Regards,
Chua Wen Ching :p

Re: VB6/VB.NET Case Is < 0 in c# ???

Marc Clifton2-Aug-03 15:04

Marc Clifton

2-Aug-03 15:04

if (ShipPtchSM < 0)
{
 ...
}
else if (ShipPtchSM > 0)
{
 ...
}

etc...

Every line of code is a liability - Taka Muraoka
A doable project is one that is small enough to be done quickly and big enough to be interesting - Ken Orr

Latest AAL Article
My blog

Re: VB6/VB.NET Case Is < 0 in c# ???

J. Dunlap2-Aug-03 15:08

J. Dunlap

2-Aug-03 15:08

You have to use if, elseif, and else.

if(ShipPitchSM>0)
{
   ShipPitchSM-= Friction;
   ShipPitchSM = Math.Max(0,ShipPitchSM);
   ShipPitchSM = Math.Min(ShipPitchSM,0.03);
}else
{
   ShipPitchSM += Friction;
   ShipPitchSM = Math.Min(0,ShipPitchSM);
   ShipPitchSM = Math.Max(-0.03,ShipPitchSM);
}

"Blessed are the peacemakers, for they shall be called sons of God." - Jesus

"You must be the change you wish to see in the world." - Mahatma Gandhi

Re: VB6/VB.NET Case Is < 0 in c# ???

Marc Clifton2-Aug-03 15:09

Marc Clifton

2-Aug-03 15:09

Ah, even better than my example. Very nice.

Marc

Every line of code is a liability - Taka Muraoka
A doable project is one that is small enough to be done quickly and big enough to be interesting - Ken Orr

Latest AAL Article
My blog

Re: VB6/VB.NET Case Is < 0 in c# ???

J. Dunlap2-Aug-03 15:11

J. Dunlap

2-Aug-03 15:11

But you've got the best idea in your second post. Wink | ;)

"Blessed are the peacemakers, for they shall be called sons of God." - Jesus

"You must be the change you wish to see in the world." - Mahatma Gandhi

Re: VB6/VB.NET Case Is < 0 in c# ???

Chua Wen Ching2-Aug-03 20:11

Chua Wen Ching

2-Aug-03 20:11

Thanks everyone.

So switch/case does not accept conditions... i need to do if/else for it!

Thanks a lot.

Regards,
Chua Wen Ching :p

Re: VB6/VB.NET Case Is < 0 in c# ???

Marc Clifton2-Aug-03 15:08

Marc Clifton

2-Aug-03 15:08

Better yet:

AdjustParam(ref double param, double friction)
{
   if (param < 0)
   {
     param=param + friction;
     if (param > 0) param=0;
     if (param < -0.03) param=-0.03;
   }
   else
   if (param > 0)
   {
     param=param - friction;
     if (param < 0) param=0;
     if (param > 0.03) param=0.03;
   }
}

then call:

AdjustParam(ref ShipPitchSM, Friction);
AdjustParam(ref ShipYawSM, Friction);
AdjustParam(ref ShipRollSM, Friction);

and there's other optimizations you can make too. Get then sign of the parameter and you can eliminate the if-else clause. Put the bounds checking in a separate helper function. Things like that.

Marc

Every line of code is a liability - Taka Muraoka
A doable project is one that is small enough to be done quickly and big enough to be interesting - Ken Orr

Latest AAL Article
My blog

Re: VB6/VB.NET Case Is < 0 in c# ???

Csharp™3-Aug-03 4:29

Csharp™

3-Aug-03 4:29

you can easily do it with the <color="blue">switch statement Smile | :)

( it is really an equivalent to Select Case , just have to modify it slightly to tell if it's a + value or not, here's a simple example i made.
C#:

<font color="blue">private</font> <font color="blue">void</font> val() <br> { <br> 	<font color="#0000FF">int</font> x =-1; <br> 	<font color="#0000FF">switch</font>(x.CompareTo(0)<0) <br> 	{ <br> 		<font color="#0000FF">case true</font>: <br> 			MessageBox.Show("the value is less than zero!"); <br> 		<font color="#0000FF">break</font>; <br> 		<font color="#0000FF">case false</font>: <br>                         MessageBox.Show("the value is greater than zero!"); <br> 		<font color="#0000FF">break</font>; <br> 	} <br> } <br>

hope it helps to understand the switch statement a bit more Smile | :)

Re: VB6/VB.NET Case Is < 0 in c# ???

Marc Clifton3-Aug-03 5:22

Marc Clifton

3-Aug-03 5:22

This is not exactly equivalent though.

In the original code, the test is '< 0' and '> 0'. Your code is '< 0' and '>= 0', causing an inneficiency when x==0 (not that the original code was very efficient to begin with!)

If you wanted to preserve the logic of the original test with a switch statement, you would need to properly qualify the test if a trinary operator:

switch (x < 0 ? -1 : x > 0 ? 1 : 0)
{
 case -1: // < 0
 ...
 case 0:  // == 0
 ...
 case 1:  // > 0
 ...
}

Hope that helps to understand how refactoring needs good test cases! Big Grin | :-D

Marc

STL, a liability factory - Anonymously
A doable project is one that is small enough to be done quickly and big enough to be interesting - Ken Orr

Latest AAL Article
My blog

Re: VB6/VB.NET Case Is < 0 in c# ???

LovelyXiaoXinXin3-Aug-03 16:49

LovelyXiaoXinXin

3-Aug-03 16:49

Why don't you use switch ()

Unwanted XML attribute

Omega5012-Aug-03 14:27

Omega501

2-Aug-03 14:27

I'm writing a small app for my own use (mostly to play with an XML datastore) I'm trying to add a node to the xml document. This works fine, except that it keeps on adding an empty xmlns attribute to the new nodes. Is there anyway of stopping this?

I am contructing the xml node from a string

<NewNode>
  <DataNode />
</NewNode>

and inporting it into the xml document like this.

<br />
xmlContactsList["Root"].AppendChild(NewNode);<br />

But the result I keep getting is

<doctype tag>
<Root>
  <NewNode xmlns="">
    <DataNodes />
  </NewNode>
</Root>

Is there anyway of getting rid of the xmlns attribute? The root node already has the correct value for this.

docking a datagrid

mikemilano2-Aug-03 12:23

mikemilano

2-Aug-03 12:23

i have a form which includes search parameters at the top.

i want the datagrid to begin directly under the search fields.

the data grid needs to stretch from left to right no matter what size the form is, but i do not want to dock it to the bottom.

when i dock it to the bottom, then maximize, there is a big gap between the datagrid and the search fields.

is there any way to align the top of the data grid to a point, and still make it stretch from left to right no matter what the size of the form is?

Re: docking a datagrid

Furty2-Aug-03 19:51

Furty

2-Aug-03 19:51

If you're working in the VS.Net forms designer, set the Dock property to None, then set the Anchor property to all sides.

If you're hand coding, do it like this:

dataGrid.Dock = DockStyle.None;
dataGrid.Anchor = (((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);

System properties

Davy Mitchell2-Aug-03 8:54

Davy Mitchell

2-Aug-03 8:54

Hi Folks,

How can I access system properties so that my app will match the appearance of the User's setting? Particularly after Fonts and colours.

Thanks,

Davy

My Personal Blog - Homepage.
Scottish News - Angus Blog, Perth Blog and Dundee Blog

Re: System properties

Nick Parker2-Aug-03 9:18

Nick Parker

2-Aug-03 9:18

Davy Mitchell wrote:
How can I access system properties so that my app will match the appearance of the User's setting? Particularly after Fonts and colours.

Are you simply interesting in persisting user settings which you can load when the application starts and saving them when it ends?

-Nick Parker

Re: System properties

Davy Mitchell2-Aug-03 9:43

Davy Mitchell

2-Aug-03 9:43

Hi Nick,

No - I am after the system settings that can be set under the Appearance tab of the Display Properties (rightclick desktop).

Davy

My Personal Blog - Homepage.
Scottish News - Angus Blog, Perth Blog and Dundee Blog

Re: System properties

S O S3-Aug-03 2:23

S O S

3-Aug-03 2:23

Maybe Control.DefaultFont and Control.DefaultIForgotWhat can help you.

deepcopy

zecodela1-Aug-03 19:40

zecodela

1-Aug-03 19:40

hi,
i have a object in a ArrayList. i need to search a record in list and return it. since it is in multi-thread environment, i want to return a deepcopy of that object rather return the reference of it. and, release lock of the list.
how can i do?
thanks,
jim

Re: deepcopy

Arjan Einbu2-Aug-03 0:36

Arjan Einbu

2-Aug-03 0:36

Take a look at ManojG's article: An insight into cloning objects in .NET[^]

Hide horizScrollBar in DataGrid

Ista1-Aug-03 12:27

Ista

1-Aug-03 12:27

How can I hide the Horiz scroll bar

public myClass : DataGrid
{

public myClass() : base()
{
this.HorizScrollBar.Visible = false;
}

doesnt do anything?

I'm not an expert yet, but I play one at work. Yeah and here too.

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