[RESOLVED] checkedlistbox remove

I'm trying to remove selected items. So far I'm at

Code:

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                        if(checkedListBox1->CheckedItems->Count != 0)
                        {
                                String ^ checked;
                                for(int i = 0; i < checkedListBox1->CheckedItems->Count; i++)
                                {
                                        checked = String::Concat(checked, checkedListBox1->CheckedItems[i],"\n");
                                        checkedListBox1->Items->Remove(checkedListBox1->CheckedItems[i]);
                                }
                                MessageBox::Show(checked, "Deleted from list");
                        }

---

But it deletes only HALF of selected items.
Seriously, wth is wrong here? (O.o)

This looks like C# code, but my guess is that checkedListBox1->CheckedItems->Count is decremented when you remove each item. Start at checkedListBox1->CheckedItems->Count and go to 0.

Viggy

Quote:

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Originally Posted by MrViggy

This looks like C# code [...].

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You're almost right: It's C++/CLI. But your proposed solution is right on the spot and should work. :)

Migeria, Your code is C++/CLI and we have a specific forum for this around here: http://www.codeguru.com/forum/forumdisplay.php?f=17. Your chance to get answers for questions about that language are better there.

But MrViggy already has correctly diagnosed your problem and made a suggestion that should work. Also, we recently had another thread about the same problem: http://www.codeguru.com/forum/showthread.php?t=507532. This is about the MFC CListCtrl though, but it contains some more alternative solutions that should apply to your case as well.

Ah, and... Welcome to CodeGuru! :)

Thanks for both of you :D Since I'm not native English speaking person, it took some time to get what I should do, but well... in the end I succeeded Y(^-^)Y

So thats how those drugs for headache are called xD C++/CLI. Thanks I will try to remember those random letters.

And here's reference for future generations:

Code:

---

if(checkedListBox1->CheckedItems->Count != 0)
{
        String ^ s;
        for(int x = 0; x < checkedListBox1->CheckedItems->Count; checkedListBox1->CheckedItems->Count)
        {
                s = String::Concat(s, checkedListBox1->CheckedItems[x],"\n");
                checkedListBox1->Items->Remove(checkedListBox1->CheckedItems[x]);
        }
        MessageBox::Show(s, "Istrinti is pasirinkimo saraso");
}

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Well, this code works, so this is primarily FYI, but it can be simplified considerably.

The part marked in red in the following line has no effect and can be omitted as well:

Code:

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        for(int x = 0; x < checkedListBox1->CheckedItems->Count; checkedListBox1->CheckedItems->Count)

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You certainly know that this code is meant to advance the loop variable (in this case x), and therefore x always remains 0 during the entire loop. (BTW, the equivalent in the for loop in post #1 actually did what it was supposed to do - and exactly that was what caused the problem.)

As a consequence of this, your code is equivalent to this:

Code:

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String ^ s;
while (checkedListBox1->CheckedItems->Count > 0)
{
        s = String::Concat(s, checkedListBox1->CheckedItems[0],"\n");
        checkedListBox1->Items->Remove(checkedListBox1->CheckedItems[0]);
}
MessageBox::Show(s, "Istrinti is pasirinkimo saraso");

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Well, strictly speaking it is not exactly equivalent. To make it that, you can wrap the whole thing in an uncontrolled {} to limit the lifetime of s.

BTW, forums like this one are also a great English training. :)

Quote:

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Originally Posted by Eri523

you can wrap the whole thing in an uncontrolled {} to limit the lifetime of s.

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could you explain or show example of what is "uncontrolled {}".
I think I got it wrong, but I can't find any reference on G**gle.

Quote:

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Originally Posted by Migeria

could you explain or show example of what is "uncontrolled {}".

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The "uncontrolled block" is the outermost pair of {} in the following code snippet, a modified version of the snippet from my last post:

Code:

---

{
        String ^ s;
        while (checkedListBox1->CheckedItems->Count > 0)
        {
                s = String::Concat(s, checkedListBox1->CheckedItems[0],"\n");
                checkedListBox1->Items->Remove(checkedListBox1->CheckedItems[0]);
        }
        MessageBox::Show(s, "Istrinti is pasirinkimo saraso");
}

---

I call it "uncotrolled" because it is not dependent on a loop construct or, like in your code in post #1, an if statement. Its use is, as I already memtioned above, while it doesn't influence the control flow as such, it limits the lifetime of the variable s.

Quote:

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I think I got it wrong, but I can't find any reference on G**gle.

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I'm not sure wether this term is "canonical" enough to be easily used as a search term for a search engine.

BTW "Google" is not one of the "evil words" here on GodeGuru (while the name of at least one other popular site is). To the contrary: It's a quite common recommendation here to try this before asking a question here.

Now that was easy to understand ^-^
I thought that {} could be used only with conditions, loops, function, classes, structures and so on~~~~

Quote:

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Originally Posted by Eri523

It's a quite common recommendation here to try this before asking a question here.

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G**gle word is evil itself =D 'cause sometimes it doesn't find what I need