C# checkedlistbox differentiate between ItemCheck via code and mouse click - winforms

Question

I'm using C# VS2008, WinForm application
I have a checkedlistbox control on my form (win-form application)
In the code I check some items in checkedlistbox using the SetItemChecked(index, false) method and it raise the event ItemCheck.
I also allow the user to check items in that checkedlistbox and it also raise the event ItemCheck when the user check or uncheck an item.
How can I find in the ItemCheck event how this event occur (via code or via user keyboard/mouse input)?
Thanks.

Answer 1

I think that there is no a simple way to differentiate the situation using code.
The only thing that comes to mind is through the use of a global form variable:
public class Form1:Form
{
bool _isCodeClick = false;
.....
// Somewhere in your code
_isCodeClick = true;
checkedListBox1.SetItemChecked(index, true);
_isCodeClick = false;
.....
private void CheckedListBox1_ItemCheck(Object sender, ItemCheckEventArgs e)
{
if(_isCodeClick == true)
{
// Do processing for click by code
}
else
{
// Do processing for click by user
}
}
}
If you go for this solution remember to take additional steps to correctly trap exceptions that could bypass the reset of the global variable to the false state.
Probably using advanced manipulation of keyboard and mouse events you could reach a reasonable way to identify what has caused the ItemCheck event, but sometime some solutions are too complex and not worth it.
EDIT: Reviewing my answer I feel the need to add a little change to reduce the maintaining problems that this esponse implies.
The code that set the boolean variable and call the SetItemChecked should be encapsulated in a separate function like this
private void SetItemCheckedFromCode(int index, bool toSet)
{
try
{
_isCodeClick = true;
checkedListBox1.SetItemChecked(index, true);
}
finally
{
_isCodeClick = false;
}
}