Re: Help with Drawing Polygons - C# Discussion Boards

Re: When To Use 'this' in C#

DaveyM692-Feb-10 12:28

DaveyM69

2-Feb-10 12:28

Kevin McFarlane wrote:
A lot of MS's generated code uses this.xxx

A FormX.Designer.cs is full of it. I guess the principles are:

1. In a container (such as a form) that holds many different objects, explicitly stating the object that you are using a method or property of is probably good practice and leaves no room for ambiguity.

2. It allows for parameters and fields to have the same name (much more likely to occur in auto generated code). If you always access the field with this then there will be no issues in this situation.

Personally, I only use it in my hand written code in case 2 and only where needed.

Dave

Tip: Passing values between objects using events (C#)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Re: When To Use 'this' in C#

Kevin McFarlane3-Feb-10 0:08

Kevin McFarlane

3-Feb-10 0:08

Those are good rules of thumb. Smile | :)

Kevin

Re: When To Use 'this' in C#

Mycroft Holmes2-Feb-10 12:08

Mycroft Holmes

2-Feb-10 12:08

I find I use this whenever I refer to a form object ie this.Close() but almost nowhere else, not even when referring to a control on the form, weird!

Still I hated using

Me

in VB whereas this in c# doesn't offend me nearly as much!

Never underestimate the power of human stupidity
RAH

Re: When To Use 'this' in C#

AspDotNetDev2-Feb-10 17:05

AspDotNetDev

2-Feb-10 17:05

Ennis Ray Lynch, Jr. wrote:
keyboard shortcut for intellisense (ctrl + space)

Thanks for the tip! How about this:

// Save keystrokes and confuse other developers.
private SomeType i{get{return this;}}

// Make use of this (aka Me, aka i).
public SomeMethod()
{
    i.Close();
}

$Shucks | :-\$ Poke tongue | ;-P

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Re: When To Use 'this' in C#

Luc Pattyn2-Feb-10 17:17

Luc Pattyn

2-Feb-10 17:17

aspdotnetdev wrote:
this (aka Me, aka i)

aka notThat

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
[The QA section does it automatically now, I hope we soon get it on regular forums as well]

Re: When To Use 'this' in C#

PIEBALDconsult2-Feb-10 12:37

PIEBALDconsult

2-Feb-10 12:37

I use it to piss people off.

Help with Drawing Polygons

Raztor02-Feb-10 7:51

Raztor0

2-Feb-10 7:51

Hello once again. I just made a program to draw triangles in a way that makes a nice effect, here's a picture:

http://i276.photobucket.com/albums/kk2/Raztor0/Capture.jpg[^]

Now, the way I'm drawing this is I have an array of 80 points which I'm telling C# to draw with the DrawPolygon command. Can you see that line that goes through the middle of the triangles? That line is a line connecting the first and last point in the array, can I somehow prevent C# from connecting that last line? Is there a different command that lets me connect every point in sequence?

Thanks for your time Smile | :)

Re: Help with Drawing Polygons

Luc Pattyn2-Feb-10 8:18

Luc Pattyn

2-Feb-10 8:18

Hi,

a polygon[^] is a closed path by definition, and Graphics.DrawPolygon closes the path for you if you haven't done so yourself. That is all documented in MSDN. The class holds more drawing methods though.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
[The QA section does it automatically now, I hope we soon get it on regular forums as well]

Re: Help with Drawing Polygons

Raztor02-Feb-10 8:24

Raztor0

2-Feb-10 8:24

Thank you for the info, but is there a way to connect each point without saying Graphics.DrawLine(pen, point, point)? I will do that if I have to but I really don't want to Frown | :(

Re: Help with Drawing Polygons

Luc Pattyn2-Feb-10 8:26

Luc Pattyn

2-Feb-10 8:26

Raztor0 wrote:
is there a way to connect each point without ...

yes, and I already said that.
like always, it starts by reading the documentation.
I tend not to spoon feed lazy people.

Unsure | :~

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

I only read code that is properly formatted, adding PRE tags is the easiest way to obtain that.
[The QA section does it automatically now, I hope we soon get it on regular forums as well]

Re: Help with Drawing Polygons

Raztor02-Feb-10 8:30

Raztor0

2-Feb-10 8:30

Ah, alright. I didn't get that, I thought you were trying to say that DrawPolygon is explained there, which made me think that it's explaining what I already know. Thanks anyway, I'll go check it out.

Re: Help with Drawing Polygons

Raztor02-Feb-10 8:40

Raztor0

2-Feb-10 8:40

Okay so I found DrawLines, this is exactly what I need :P Thank you for your help once again Big Grin | :-D

TAPI Platform Invoking

saeidfarahi2-Feb-10 7:44

saeidfarahi

2-Feb-10 7:44

I want to write a program communicating a modem to send and receive special data(in format of string) to/from other modems.I have some questions:
1- For this program, should I use kdtele library or TAPI?
2- I couldn't find any complete user reference for kdtele! can anyone post me any link or other documentations?
3- After I couldn't work with kdtele, as I said why, I started searching about TAPI and realized there isn't any c# library for it and I have to use Platform Invokation to use tapi3.dll COM component, but here
's my question:
Do I need to PInvoke all c++ functions, messages, members and structs of tapi3.dll which are needed to write my program in c++ and then use the invoked class in c#? or does any one did this PInvoke job?!

Re: TAPI Platform Invoking

DaveyM692-Feb-10 7:49

DaveyM69

2-Feb-10 7:49

I've never worked with it but this google search[^] shows some promising results

Dave

Tip: Passing values between objects using events (C#)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Why are you using VB6? Do you hate yourself? (Christian Graus)

How to add an attribute to a XML node

Petri Luoto2-Feb-10 6:24

Petri Luoto

2-Feb-10 6:24

Hi,

I have a problem, because I cannot find a method like xmlWriter.WriteAttributeString, which would add an attribute to a single node (see below the underlined node <instdamt> with an attribute Ccy="EUR").

The WriteAttributeString adds nicely an attribute to an element, like for example <Amt Ccy="EUR">, if I put it after xmlWriter.WriteStartElement("Amt"). But that is not the problem. I will get an exception if I put it after the xmlWriter.WriteElementString("InstdAmt", txtInstdAmt.Text).

So, what should I do to get the attribute added to a node, like the example below? It doesen't seem to be the most common need, so therefore I didn't find much from google either.

<PmtId>
  <EndToEndId>20090821-E000001</EndToEndId>
</PmtId>
<Amt>
  <InstdAmt Ccy="EUR">100.01</InstdAmt>
</Amt>
<CdtrAgt>
  <FinInstnId>

Thanks
Petri

Re: How to add an attribute to a XML node

Dan Mos2-Feb-10 7:06

Dan Mos

2-Feb-10 7:06

I don't know much about xmlWriter(DOM in general). Haven't used for any but the simplest things.

This functionnal XLINQ creation/construction sure does work:

XDocument yourDoc= 
		new XDocument(
            	new XDeclaration("1.0", "UTF-8", "yes"),
				      new XElement("Amt",
					   new XElement("InstdAmt","101.01")
 		                	   	new XAttribute("Ccy", "EUR")

Re: How to add an attribute to a XML node

Not Active2-Feb-10 7:46

Not Active

2-Feb-10 7:46

Petri Luoto wrote:
So, what should I do to get the attribute added to a node,

Use the tools correctly. It won't work the way you are trying because it would produce an invalid document.

writer.WriteStartElement("Amt");
writer.WriteStartElement("InstdAmt");

writer.WriteAttributeString("Ccv", "EUR");
writer.WriteValue("100.01");

writer.WriteEndElement(); // End InstdAmt
writer.WriteEndElement(); // End Amt

I know the language. I've read a book. - _Madmatt

Re: How to add an attribute to a XML node

Petri Luoto2-Feb-10 8:24

Petri Luoto

2-Feb-10 8:24

Great!

I obviously tought that you can put WriteAttributeString also after WriteElementString as you can do with WriteStartElement.

This solved my problem, for now Smile | :)

Thanks for prompt answers.
Petri

sort datagridview

jashimu2-Feb-10 5:45

jashimu

2-Feb-10 5:45

Hi all, I have two questions .
1. How do I copy one datagridview to another.
2. how do I sort a specefic column. for example I have
col A, colB, colC. I want to sort colB only when data is loaded.
for copying or loading from one grid to another I have done something like this
and it is working but not sure it is a right thing to do or not.

for (int j = 0; j < dataGridView1.Rows.Count; j++)<br />
                {<br />
                        dataGridView2.Rows.Add();// adding row before inserting data in it<br />
                        for (int i = 0; i < 5; i++)<br />
                        {<br />
                          dataGridView2.Rows[j].Cells[i].Value = dataGridView1.Rows[j].Cells[i].Value;<br />
                         }<br />
                }<br />

thanks in advance

Remove all characters in a string up to and including a specified pattern

MarkB1232-Feb-10 5:27

MarkB123

2-Feb-10 5:27

Hi, can someone give any advice on the following problem I have in C# 2...

I have a string such as "this_is_a test|XXmoretexthere". I need a bit of code that if I specify |xx as the sepertor, will return back to me everything after "|xx"
so I have "moretexthere" as a result.

The pattern I pass may vary content and length. The current pattern is held in a string variable. Should the pattern occur more than once in the string, I only need to return everything after the first occurrence.

Whatever solution I use, it needs to be fast as it will run in a loop possibly many thousands of times.

Many thanks for any advice.

Re: Remove all characters in a string up to and including a specified pattern

PIEBALDconsult2-Feb-10 5:31

PIEBALDconsult

2-Feb-10 5:31

A Regular Expression, or IndexOf and Substring.

Re: Remove all characters in a string up to and including a specified pattern

sanforjackass2-Feb-10 5:33

sanforjackass

2-Feb-10 5:33

it is only an idea you can use find and replace first to change any '|xx' with ';' then use string properties to find the place
!!!!!

Re: Remove all characters in a string up to and including a specified pattern

OriginalGriff2-Feb-10 5:42

OriginalGriff

2-Feb-10 5:42

He did say he wanted something fast: Yours involves two searches and two string copies. (Remember strings are immutable, so find and replace will create a new copy of the string, rather than alter the existing one.)

All those who believe in psycho kinesis, raise my hand.

My Badger | [badger,badger,badger,badger...]

's gonna unleash hell on your ass. Badger | [badger,badger,badger,badger...]

tastic!

Re: Remove all characters in a string up to and including a specified pattern

OkkiePepernoot2-Feb-10 6:01

OkkiePepernoot

2-Feb-10 6:01

string initialText = "this_is_a test|XXmoretexthere";
string searchString = "|XX";
int lastIndexFound = initialText.LastIndexOf(searchString);
if (lastIndexFound > 0)
{
  MessageBox.Show(initialText.Substring(lastIndexFound + searchString.Length));
}
else
{
  MessageBox.Show("Patternt not found");
}

Not sure if this is fast enough...

Not sure if the search is case sensitive otherwise....

Re: Remove all characters in a string up to and including a specified pattern

MarkB1232-Feb-10 8:28

MarkB123

2-Feb-10 8:28

Hi folks, thanks for the replies.
Regarding a RegEX, can someone supply an example of the correct syntax for my requirements. I've tried Googling this but I just get confused by it's syntax.
Thanks.

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