Unchecked Items in CheckedListBox

[Jennifer84]

I have a CheckedListBox with 95 Checked Items and 5 Unchecked Items.
Every Checked and Unchecked Item has a "string" name.
What I am trying to do is to locate All the Unchecked Items in this box and put these strings into my vector with the pushback method: Unchecked.push_back();

The thing is that I am not sure how I will find all the Unchecked Items.
I have found ->CheckedItems but nothing that relate to Unchecked Items.
Perheps something with Checked == false could be used in any way here ?

std::vector<string> Unchecked;
CheckedListBox1->CheckedItems;

[Radical Edward]

The Items property gives you everything, and from there it's no trouble to get the checked state for each item.

[Jennifer84]

Thanks. I have tried to come up with this code that checks for Items that are unchecked.
There is 1 thing that I might wonder.
In this case I know that there is 100 Items, so I use a for loop < 100.
Is there any way to loop to the END of the ListBox ?

std::vector<string> UncheckedLines;
std::string temp;
			 
for(int i = 0; i < 101; i++)
{
	String^ Temp = CheckedListBox1->SetItemCheckState(i, CheckState::Unchecked);

	MarshalString(Temp, temp);
				 				
	
	UncheckedLines.push_back(temp);
			
}

The Items property gives you everything, and from there it's no trouble to get the checked state for each item.

[Radical Edward]

The Items property represents a collection. You can use the Count property of the collection to query how many items are in the CheckedListBox.

[Jennifer84]

I have tried to put the code like this and also used the Count Property to know how many Items there is in the box.
When running this code I get an Error Message: Invalid Null Pointer

I beleive I am looping through the ListBox and check for Unchecked Items.
When I find a Unchecked Item I put this to the String^ Temp.
I convert Temp to a std::string temp and push_back this into the vector UncheckedSymbols.
Any idéas why I get this Errormessage ?

std::vector<string> UncheckedSymbols;
std::string temp;
String^ Temp;
			 
for(int i = 0; i < (CheckedListBox1->Items->Count + 1); i++)
{
	if( CheckedListBox1->GetItemCheckState(i) == ::CheckState::Unchecked )
	{
	Temp = CheckedListBox1->Items->ToString(); 
	MessageBox::Show(Temp); //Just Show the Unchecked index
	}

 MarshalString(Temp, temp);
					 
 UncheckedSymbols.push_back(temp);
}

[Radical Edward]

You have an off by one error. Indexes for the Items collection are zero based, so your loop should look like this:

for(int i = 0; i < CheckedListBox1->Items->Count; i++)

[Jennifer84]

Thanks, I did change to: for(int i = 0; i < CheckedListBox1->Items->Count; i++)
2 strange things is still happening though.
In the ListBox I do now have 8 checked Items. If I now execute the code I will still have this Error.
If I Uncheck the First Item in the listBox, I will will have a MessageBox appear.
The message in the MessageBox says:

System.Windows.Forms.CheckedListBox+ObjectCollection

If I uncheck Item 2 and 3, I will have 2 Messages like that wich anyway tell that the loop in a way is working.

What I am also after is the string that the Unchecked Item has. The Items has names like below.
So I am trying to get these stringnames to appear in the MessageBox when showing:
A
AB
ABC
ABCD

etc....

You have an off by one error. Indexes for the Items collection are zero based, so your loop should look like this:

for(int i = 0; i < CheckedListBox1->Items->Count; i++)

[Jennifer84]

....

[Radical Edward]

> If I now execute the code I will still have this Error.
Sorry, Edward was too lazy to read your code closely. The error is caused because you're trying to marshal a string that doesn't exist. Pretend that no items are unchecked for a minute and the if statement can go away. That makes the error easier to see:

std::vector<string> UncheckedSymbols;
std::string temp;
String^ Temp;

for(int i = 0; i < CheckedListBox1->Items->Count; i++)
{
  MarshalString(Temp, temp);
  UncheckedSymbols.push_back(temp);
}

You don't initialize Temp to an object, so it remains null. Ed suggests moving those two lines into the if statement along with both of the temporaries:

std::vector<string> UncheckedSymbols;

for(int i = 0; i < CheckedListBox1->Items->Count; i++)
{
  if( CheckedListBox1->GetItemCheckState(i) == ::CheckState::Unchecked )
  {
    String^ Temp = CheckedListBox1->Items->ToString();
    std::string temp;

    MessageBox::Show(Temp); //Just Show the Unchecked index

    MarshalString(Temp, temp);
    UncheckedSymbols.push_back(temp);
  }
}

> System.Windows.Forms.CheckedListBox+ObjectCollection
That's expected. The ToString method usually won't give you the property you want, which Ed guesses is the text property of an individual list item. Try this instead:

std::vector<string> UncheckedSymbols;

for(int i = 0; i < CheckedListBox1->Items->Count; i++)
{
  if( CheckedListBox1->GetItemCheckState(i) == ::CheckState::Unchecked )
  {
    String^ Temp = CheckedListBox1->GetItemText(CheckedListBox1->Items[i]);
    std::string temp;

    MessageBox::Show(Temp); //Just Show the Unchecked index

    MarshalString(Temp, temp);
    UncheckedSymbols.push_back(temp);
  }
}

[Jennifer84]

Thank you for help !.

This did work very good...