ListBox SelectionMode Single multiple select
<p>I'm having a rather strange problem while working with a <code>ListBox</code> on a <code>WPF</code> program.
I've defined my <code>ListBox</code> <code>SelectionMode</code> as <code>Single</code>, but it appear that even if visually I cannot select multiples items, it happens in the code.
As can be seen here :
<a href="https://i.stack.imgur.com/63LgM.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/63LgM.jpg" alt="SelectionModeSingleWithMultipleSelected"></a></p>

<p>When trying to do a workaround, I tried to use the function UnselectAll, it rather strangly still leave an item selected :
<a href="https://i.stack.imgur.com/Tt6T7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Tt6T7.jpg" alt="UnselectAllStillSelected"></a></p>

<p>And as a last gift, once multiple items have been selected, if I try to click on my unselected visualy, selected in the code, item my application crash with a System.ArgumentException (I suppose it tries to select my item, that's already selected in fact, so it crashes because of adding a perfect duplicate ?)
<a href="https://i.stack.imgur.com/FVMDT.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FVMDT.jpg" alt="ApplicationCrashOnListBoxClick"></a></p>

<p>I looked into <a href="https://stackoverflow.com/questions/3843784/listbox-is-selecting-many-items-even-in-selectionmode-single">ListBox is selecting many items even in SelectionMode=&quot;Single&quot;</a> that had kindof the same problem, but in my case I cannot visually select multiples items, and my items are completly distinct so it doesn't really help.</p>

<p>I don't have any custom behavior on ListBox.Click that could mess with something ...</p>

<p>my <code>ListBox.ItemsSource</code> is bound to a list of Items.
I will decrement the value of a property of the selected Item when calling <code>useItem</code> on it, but it is still the same item (I don't recreate it/remove it then add it again)</p>

<p>Where is my problem coming from ?
How can I fix it ?</p>