asked on

c# 2010 winforms list of classes problem

Hi

I have a class, like this:

class MyClass
{

public int ID {get; set;}
public string[] Stuff = new string[10];

public MyClass(int ID, string[] Stuff)
{

this.ID = ID;
this.Stuff = Stuff;


}

}

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simple enough...

I have a list of this class, which I am adding to like so

List<MyClass> myStuff = new List<MyClass>();

myStuff.add(new MyClass(id,stuff));

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this is fine when I add the first entry, but for subsequent entries, the 'stuff' array is being applied to ALL entries in the list, not just the new one.

I am baffled as to why, I am sure someone can enlighten me.

cheers

CD

Carl Tawn

You mean you are passing the same instance of "stuff" to each MyClass object? What you are actually passing is a pointer to the array, not a copy.

You should look at creating a copy of the array inside each MyClass instance if you want them to remain separate.

cycledude

ASKER

well, its the same array structure as in

string[] stuff = new string[10]

but the contents of the string are different on each iteration

Carl Tawn

But are you overwriting the contents of the array in each iteration, or are you reinitializing the array each time.

i.e. Are you doing:

string[] stuff = new string[10];

for ( ... )
{
    stuff[0] = "something";
    stuff[1] = "something else";
    ...
}

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Or are you doing:

string[] stuff;

for ( ... )
{
    stuff = new string[10];
    stuff[0] = "something";
    stuff[1] = "something else";
    ...
}

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cycledude

ASKER

1st one ...

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Carl Tawn

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cycledude

ASKER

Hi

thanks, I will try to re-structure the code so that I can re-initialise the array on each iteration...

will let you know how i get on.

cycledude

ASKER

thanks, a little restructuring and it has worked a treat.