Re: Assign By Reference - C# Discussion Boards

OriginalGriff9-Oct-10 6:19

9-Oct-10 6:19

As DaveAuld says, go for the web service.
Presumably, you are using software activation as a way of securing your income and preventing piracy. If you expose your sql connection publicly so the WinForm app can access it, do you think that helps? Or creates a big security hole for naughty people to jump right through and pre-activate as many copies as they want?

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

Assign By Reference

thenutz729-Oct-10 4:08

thenutz72

9-Oct-10 4:08

Is there any way to assign an object by address in C#? (I want to use the word reference but it complicates the question). It's like you can have reference behaviour through functions that you cannot have WITHIN the function.

Example:

private MyClass m_MyClass;
public void MyFunction(ref MyClass objIn)
{
objIn = new MyClass() //Creates a new object in the function that called this procedure
}

But if did
private MyClass m_MyClass;
public void MyFunction(ref MyClass objIn)
{
m_MyClass = objIn;
}
public void SomeOtherFunction()
{
m_MyClass = new MyClass() //Now the calling function's object is forever unlinked
}

My question is:
//Is there some way to do something more like
m_Myclass = ref objIn; //????

I thank everyone who wants to be helpful but I am not looking for a workaround, I am trying to advance my understanding of .NET. Thanks again, All.

Re: Assign By Reference

PIEBALDconsult9-Oct-10 4:18

PIEBALDconsult

9-Oct-10 4:18

Ummm... what? It's hard to read that code; put it in pre tags (select it and click code block).

thenutz72 wrote:
It's like you can have reference behaviour through functions that you cannot have WITHIN the function.

C# (.net) is all about references.

thenutz72 wrote:
is forever unlinked

I don't know what that's supposed to mean.

thenutz72 wrote:
way to do something more like

No, that's silly.

Re: Assign By Reference

harold aptroot9-Oct-10 4:45

harold aptroot

9-Oct-10 4:45

This really doesn't make any sense to me.
What does this even mean?

thenutz72 wrote:
m_Myclass = ref objIn;

Re: Assign By Reference [modified]

Keith Barrow9-Oct-10 6:28

Keith Barrow

9-Oct-10 6:28

thenutz72 wrote:
It's like you can have reference behaviour through functions that you cannot have WITHIN the function.

Pretty much everything is done by reference:

MyObject foo = new MyObject();

foo is a reference to the object created by the constructor. When it gets used it is automatically de-referenced, see this[^] for the c# boxing and unboxing model. When you pass an object to a method it is passed as a reference by default, you have to tell the method if you want it passed by value.

If you need pointers you have to use ~~unmanaged~~unsafe code, where pointers are available, but in C# you rarely need it. I've being doing this for 10 years, and the only time I had to use pointers was during some interop work I was doing. Oh and a another time after I'd just graduated using c++ and didn't know how C# really worked, which was a bit embarrasing Smile | :)

Finally, please tag up your code with <pre> , it makes it easier to read. Otherwise you'll get responses of varying degrees of snottiness.

[edit]: When I said unmanaged code, I of course meant unsafe code. Better have a nice nap and a cup of tea, I'm getting old!

Sort of a cross between Lawrence of Arabia and Dilbert.[^]

modified on Saturday, October 9, 2010 1:03 PM

Re: Assign By Reference

thenutz729-Oct-10 8:45

thenutz72

9-Oct-10 8:45

Thanks Kieth,
But in my code examples you'll see the ref keyword does act like a pointer to an object. Where as the assignment operator just assigns a reference. In the former, there are two variables with the same address. The latter, two variables that only point to the same reference.

Use of the new keyword in each scenario will confirm the difference.

I just find it odd that a function parameter can make use of pointers to objects but there's no way to duplicate that behaviour inside of a function. I was able to use unsafe code and pointers to primitive types to share addresses across multple variables. But was unable to do the same with a class/object instance.

Re: Assign By Reference

PIEBALDconsult9-Oct-10 9:07

PIEBALDconsult

9-Oct-10 9:07

You still haven't explained your question clearly.

Re: Assign By Reference

Keith Barrow9-Oct-10 9:33

Keith Barrow

9-Oct-10 9:33

First, in your code, the ref keyword is redundant, the reference pointer is passed round on objects by default, not the value itself.
Second, I'm still really not clear on your question.

private MyClass 
public void MyFunction(MyClass objIn)
{
  m_MyClass = objIn;
}

public void SomeOtherFunction()
{
  m_MyClass = new MyClass() //*Now the calling function's object is forever unlinked*
  // Actually, it isn't just unlinked, the m_MyClass reference is replaced with the one
  // you have just instantiated, The original object is orphaned and ready up for Garbage 
  // collection as no reference to it exists any more. 
}
  
public void Main()
{
  MyFunction(new MyClass());
  SomeOtherFunction();
}

Which language are you used to using and what exactly are you trying to achieve? If you need pointers you are probably going about things the wrong way in C#.

Sort of a cross between Lawrence of Arabia and Dilbert.[^]

Re: Assign By Reference

Eddy Vluggen9-Oct-10 6:55

Eddy Vluggen

9-Oct-10 6:55

Unsafe code?

unsafe
{
	int i = 1;
	Console.WriteLine((long)&i);
}

Explained on MSDN[^]

I are Troll Suspicious | :suss:

Re: Assign By Reference

Bernhard Hiller10-Oct-10 23:14

Bernhard Hiller

10-Oct-10 23:14

I am not sure if I understand what you want to accomplish. I guess you could try the out keyword instead of the ref keyword.

encrypt App.config

Jassim Rahma9-Oct-10 2:55

Jassim Rahma

9-Oct-10 2:55

How can I encrypt the entire App.config instead of encrypting just the aaSetting or ConnectionStrings only?

Re: encrypt App.config

Abhinav S9-Oct-10 3:07

Abhinav S

9-Oct-10 3:07

There is an article here that talks about this.

The funniest thing about this particular signature is that by the time you realise it doesn't say anything it's too late to stop reading it.

My latest tip/trick

Visit the Hindi forum here.

Re: encrypt App.config

PIEBALDconsult9-Oct-10 3:41

PIEBALDconsult

9-Oct-10 3:41

It sounds like you don't want to use app.config at all*; find another solution.

* I write my own config files.

Re: encrypt App.config

Jassim Rahma9-Oct-10 4:04

Jassim Rahma

9-Oct-10 4:04

I love it but I don't want others to go, open it and play with the data there!

Re: encrypt App.config

PIEBALDconsult9-Oct-10 6:07

PIEBALDconsult

9-Oct-10 6:07

That's like saying you love your girlfriend, but don't want others to... oh, wait, maybe that's not a good analogy.

compile App.config in the EXE or as DLL

Jassim Rahma9-Oct-10 2:52

Jassim Rahma

9-Oct-10 2:52

is it possible to compile the App.config withing the EXE output or as a separate DLL? will I still be able to read and write to the appSetting in this case?

Want to move a object in a window

ranjan kumar saha8-Oct-10 10:43

ranjan kumar saha

8-Oct-10 10:43

Hi,

I am new to C shrap. I need help to design s software to move object in window. there can 4-5 object which will move in window and we can use mouse to catch all tht object. hope anyone will help me to do tht.

Re: Want to move a object in a window

Luc Pattyn8-Oct-10 16:50

Luc Pattyn

8-Oct-10 16:50

Hi,

you should learn to look around; make Google your friend, and use the CodeProject search facilities. Here[^] are some results.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

Re: Want to move a object in a window

ekba8910-Oct-10 5:52

ekba89

10-Oct-10 5:52

windows forms have a property named Location. By changing it you can move objects in the window.For example to move a button in the screen you say:

yourButtonName.Location = new Point(newX, newY);

RE: Save user's re-order grid preferences

roman_s8-Oct-10 7:32

roman_s

8-Oct-10 7:32

So I've set my grid to allowReorder ,

this causes persistence on the grid order but once the program is restarted it goes back to default

can someone let me know how I can save a user's re-order preference.
Thinking it can be a property? If not maybe build a method to take care of this

Re: RE: Save user's re-order grid preferences

Searril8-Oct-10 8:03

Searril

8-Oct-10 8:03

In your DataGridView look at the ColumnHeaderMouseClick event. You can gather DataGridView1.SortedColumn.Index to know which column is being sorted on and DataGridView1.SortOrder to see if ascending or descending. Then next time you refill the grid sort on that column and order.

Re: RE: Save user's re-order grid preferences

Richard Andrew x648-Oct-10 12:13

Richard Andrew x64

8-Oct-10 12:13

I think he was asking about the order that the columns appear, left to right.

Re: RE: Save user's re-order grid preferences

Searril9-Oct-10 6:53

Searril

9-Oct-10 6:53

Ugh, that's what I get for not reading thoroughly.

Re: RE: Save user's re-order grid preferences

PIEBALDconsult8-Oct-10 15:51

PIEBALDconsult

8-Oct-10 15:51

So persist it, big deal.

Re: RE: Save user's re-order grid preferences

Mycroft Holmes9-Oct-10 2:31

Mycroft Holmes

9-Oct-10 2:31

As piebald suggested persist the order for each user. I use XML and store that sort of thing in the users application data folder. ASP would use a cookie.

Never underestimate the power of human stupidity
RAH

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