Re: Operator Overloading - C# Discussion Boards

25-Jan-09 6:24

Hello everyone,

I'm new to this forum, as well as to c# (actually its my first programming experience, since I'm at the first steps of my career change, doing it with a freind who is willing to help)...so I apologize ahead if I'm not playing it with the exact terminology etc.
So, I have this exercise in Linked Lists.
The layout of my program looks as follows:
+++++++++++++++++++++++++++
public class LinkedList{
private Link head = null;
static LinkedList Merge(LinkedList lst1, LinkedList lst2)//lst1,lst2 already sorted, returns a ref to a result merged list;.....}
public class ComparableString: string, MyCompareable{MyComparable implementation here}
interface MyComparable{operator overloading methods signature}
++++++++++++++++++++++++++++
From what I learned, operator overloading are static methods. COuld you pls advise what are the options to do it? Not a full code only the structure, methods signatures and access modifiers. I'd appreciate to know what are the considerations in chosing each way. I hope it is not too much too ask.

Many thanks for your help, hopefully my next questions will be much briefer.
Vered

DaveyM6925-Jan-09 6:49

25-Jan-09 6:49

Nothing in it to do with linked lists, but have a look at my Introduction to Operator Overloading in C#[^] article which gives examples of most operator overloads

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

Wendelius25-Jan-09 6:53

25-Jan-09 6:53

Welcome to CodeProject!

To your question, I didn't quite understand what you are after. Perhaps if you explain what you're trying to achieve, it would be clearer.

To use linked lists, I doubt that you need actually operator overloading (see: operator (C# Reference)[^]).

It seems like you're perhaps trying to implement IComparable[^] interface in order to compare different strings?

The need to optimize rises from a bad design.My articles[^]

Butter18525-Jan-09 7:02

25-Jan-09 7:02

ok..class Linked List is mostly done...I now need to write a Merge() method, and, indeed, implement an interface of my own called MyComparable . The idea of Merge() is to compare the strings of 2 linked list Merge() is given. Hope it is clear now.

Reg,
Vered

Wendelius25-Jan-09 7:22

25-Jan-09 7:22

Ok, and you need to find if two of your class instances are the same. In that case define IComparable interface to your string class and implement CompareTo method. For an example see: http://msdn.microsoft.com/en-us/library/system.icomparable.aspx[^] and http://msdn.microsoft.com/en-us/library/system.icomparable.compareto.aspx[^]

By doing this, you can compare two different instances and be able to say if they are equal or instance1 < instance2 or instance1 > instance2.

The need to optimize rises from a bad design.My articles[^]

Butter18525-Jan-09 8:26

Re: Operator Overloading [modified]

25-Jan-09 8:26

Thanks so much. I will follow to the attached links and do more homework.

Butter18525-Jan-09 20:41

25-Jan-09 20:41

Hi again. I Talked to my friend. His intention in this part of the excersise was that I practice operator overloading and interface creating and implementation. I will try the CompareTo() way as well, but would appreciate very much if you could throw me a hint of the general structure of the other way.

Thanks,
Vered

modified on Monday, January 26, 2009 5:57 AM

Wendelius26-Jan-09 7:46

c# windows datagridview [modified]

26-Jan-09 7:46

A basic tutorial of operator overloading is in Operator Overloading Tutorial[^]. Note that many operators must be overloaded in 'pairs'. For example if you overload == operator you must overload != operator. The same goes with < and > operators.

What comes to interfaces, I think you could start here: Interfaces (C# Programming Guide)[^]

Hope they help you.

The need to optimize rises from a bad design.My articles[^]

s_aslam9825-Jan-09 5:53

s_aslam98

25-Jan-09 5:53

i want to convert a column look into table look.Can any body tel me how to do this?
e.g.datagridview having 2 columns

name address
arshadaslam pk
to look like

name address
first Last
arshad aslam pk
which now have three columns:first,last,address.

modified on Sunday, January 25, 2009 12:10 PM

inserting more format into one line in word using C#

Lopy12325-Jan-09 4:32

Lopy123

25-Jan-09 4:32

Hi, I am trying to figure out insert text with different format(bold, regular, italic) into line. I am looking for whole weekend but no result. Plese help me. Thanx in Advance.

Here is my code:

using Word = Microsoft.Office.Interop.Word;
using System.Reflection;
            object oMissing = System.Reflection.Missing.Value;
            object oEndOfDoc = "\\endofdoc"; /* \endofdoc is a predefined bookmark */

            //Start Word and create a new document.
            Word._Application oWord;
            Word._Document oDoc;
            oWord = new Word.Application();
            oWord.Visible = true;
            oDoc = oWord.Documents.Add(ref oMissing, ref oMissing,
                ref oMissing, ref oMissing);

             Word.Paragraph oPara6;
            //oPara6.Range.in
            oRng = oDoc.Bookmarks.get_Item(ref oEndOfDoc).Range;
            oPara6 = oDoc.Content.Paragraphs.Add(ref oRng);
            oPara6.Range.InsertAfter("  ahoja");
            oPara6.Alignment = Microsoft.Office.Interop.Word.WdParagraphAlignment.wdAlignParagraphCenter;
            oPara6.Range.Font.Size = 12;
       
            oPara6.Format.SpaceAfter = 5;
            oPara6.Range.Font.Bold = 1;
            oPara6.Range.Text = "Vymezení jednotek v budovì";
                 
         
            oPara6.Range.InsertParagraphBefore();

            oPara6.Range.InsertBefore("ahoja ");
            oPara6.Range.InsertBefore("ahoja ");
            oPara6.Range.InsertParagraphAfter();
           // oPara6.Range.Font.Bold = 1;
            oPara6.Range.InsertBefore("ahoja ");
            oPara6.Range.InsertBefore("ahoja ");
           // oPara6.Range.Font.Bold = 0;
            oPara6.Range.FormattedText.End = 0;
            oPara6.Range.FormattedText.Bold = 1;
            oPara6.Range.Text = "Vymezení jednotek v budovì";
            oPara6.Range.InsertAfter("ahoja ");
           // oPara6.Range.Font.Bold = 1;
            oPara6.Range.InsertBefore("ahoja ");
            oPara6.Range.InsertParagraphBefore();
            //oPara6.Range.Font.Bold = 0;

Regular Expressions

the_jat25-Jan-09 3:49

the_jat

25-Jan-09 3:49

Hi! everyone,

Regular Expression sometimes match empty strings, can someone tell me why it happens and what is the use of matching empty strings(why have the original designers made it that way)? Here are some examples:

In these examples, the "Pattern" is the Pattern used for matching and the "MatchWith" is the string that is evaluated. The "Count" is the number of hits, and finally "Occurrences" lists all of them. Following is the output of a console application.

Pattern: \d*
MatchWith: 34544
String: 34544,  Pattern: \d*,   Match: |TRUE|
M String: 34544,        Position: 0,    Count: 2,       S Length: 5
Occurences:
String: 34544,  Length: 5,      Position: 0,    Success: True
String: ,       Length: 0,      Position: 5,    Success: True
-------------------------------------------------------

The above example matches an empty string, why?

Pattern: \d*
MatchWith: dfgdr
String: dfgdr,  Pattern: \d*,   Match: |TRUE|
M String: ,     Position: 0,    Count: 6,       S Length: 5
Occurences:
String: ,       Length: 0,      Position: 0,    Success: True
String: ,       Length: 0,      Position: 1,    Success: True
String: ,       Length: 0,      Position: 2,    Success: True
String: ,       Length: 0,      Position: 3,    Success: True
String: ,       Length: 0,      Position: 4,    Success: True
String: ,       Length: 0,      Position: 5,    Success: True
-------------------------------------------------------

The above example matches 6 empty strings, more than the actual length of the input string, why?

Following are examples of Lookahead:

Pattern: (?=.*\d)
MatchWith: 44
String: 44,     Pattern: (?=.*\d),      Match: |TRUE|
M String: ,     Position: 0,    Count: 2,       S Length: 2
Occurences:
String: ,       Length: 0,      Position: 0,    Success: True
String: ,       Length: 0,      Position: 1,    Success: True
-------------------------------------------------------

Above: again an empty string.

Pattern: (?=.*\d)
MatchWith: dfg
String: dfg,    Pattern: (?=.*\d),      Match: |FALSE|
M String: ,     Position: 0,    Count: 0,       S Length: 3
Occurences:
-------------------------------------------------------

Above: same failed with strings as input: "FALSE"

Pattern: (?=.*\d)
MatchWith: fgd3
String: fgd3,   Pattern: (?=.*\d),      Match: |TRUE|
M String: ,     Position: 0,    Count: 4,       S Length: 4
Occurences:
String: ,       Length: 0,      Position: 0,    Success: True
String: ,       Length: 0,      Position: 1,    Success: True
String: ,       Length: 0,      Position: 2,    Success: True
String: ,       Length: 0,      Position: 3,    Success: True
-------------------------------------------------------

Above: same pattern, but now matches of empty string

Thats all
Thanks Smile | :)

Re: Regular Expressions

Guffa25-Jan-09 5:13

Guffa

25-Jan-09 5:13

Because you have specified that it should allow a zero count. The * is the same as {0,} which specifies that the pattern should match zero or more times.

Despite everything, the person most likely to be fooling you next is yourself.

diff in need of method overloading * cons overloading

Ali_10024-Jan-09 23:58

Ali_100

24-Jan-09 23:58

I m new in .net
wel i want to know the diff. between M.overloading & C.overloading

i think ,, we can use the method after cons.overloaded by only method overloading???

& mainly ,what is the need we use or prefer them,, ??

reply me in detail

kindly reply ,,
Regards waqar

Re: diff in need of method overloading * cons overloading

DaveyM6925-Jan-09 0:12

Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:12

Do you mean method overloading and constructor overloading?

They are much the same, except constructor overloading enables you to create your object instances from different signatures that cn be used for initialization. Method overloading enables different method implementations to be called depending on the signature.

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

fracalifa24-Jan-09 23:31

Re: Preventing filedestruction after saving richtextbox contents at program end

24-Jan-09 23:31

Hi all,

the last operation of my program is to store the contents of a richtextbox to a file.
Often the contents of the file will be destroyed.
Saving by hand (button) never destroys the contents.
So it seems that the saving task (asynchronious ???) will be finished too soon at the end of my program.
I inserted a sleeptime to prevent the destruction an to give the savetask the time it needs but that's no solution steadily.

How can I detect, the end of the savetask of the richtextbox before finishing the program ?

tnx
Frank

Wendelius25-Jan-09 0:05

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:05

Since the saving can be performed in numerous ways, it's impossible to pinpoint the problem without seeing the code. One reason could be that you don't close the stream, but as said, please post the code.

The need to optimize rises from a bad design.My articles[^]

fracalifa25-Jan-09 0:26

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:26

I am simply using the safefile method of the richtextbox control, that's all.

rtxt.SaveFile(Application.StartupPath + "\\log.rtf");

and rtxt is from type System.Windows.Forms.RichTextBox

I did'nt found a method for the RTB like .flush or .close to finish the stream securely.

tnx

DaveyM6925-Jan-09 0:32

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:32

Try this in your FormClosing event handler:

using (System.IO.Stream stream = new System.IO.FileStream(
    Application.StartupPath + @"\log.rtf", System.IO.FileMode.Create))
{
    rtxt.SaveFile(stream, RichTextBoxStreamType.RichText);
}

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

fracalifa25-Jan-09 0:59

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:59

Thank you,

that sounds good, I will try this.

tnx Frank

Wendelius25-Jan-09 0:35

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:35

That should work fine but at which point are you calling this? Is the contents of rtxt possibly destroyed?

The need to optimize rises from a bad design.My articles[^]

fracalifa25-Jan-09 0:56

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:56

I call the method as last instruction in the method main[].

tnx frank

Wendelius25-Jan-09 1:02

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 1:02

At that point you won't have anything to save. Use FormClosed event instead and save the contents of the control in that event.

The need to optimize rises from a bad design.My articles[^]

DaveyM6925-Jan-09 0:07