DataGridView's SelectionChange event firing twice on DataBinding even after removing event binding

Question

This Code triggers selection change event twice. how can I prevent it ? Currently im using a flag or focused property to prevent this. But what is the actual way ?

I am using it on winfoms

EDIT

My Mistake in writing Question, here is the correct code that i wanted to ask

private void frmGuestInfo_Load(object sender, EventArgs e)
{
this.dgvGuestInfo.SelectionChanged -= new System.EventHandler(this.dgvGuestInfo_SelectionChanged);
dgvGuestInfo.DataSource=dsFillControls.Tables["tblName"];
this.dgvGuestInfo.SelectionChanged += new System.EventHandler(this.dgvGuestInfo_SelectionChanged);
}

private void dgvGuestInfo_SelectionChanged(object sender, EventArgs e)
{
//this function is raised twice, i was expecting that this will not be raised 
}

Answer 1

The event will fire each time you set the DataSource property.

\n

You should only set DataSource once.

You might be adding the same event handler twice.
Right-click on dgvGuestInfo_SelectionChanged and click Find All References.

Also, check the call stack in the event handler.

Answer 2

I have your very same problem: sometimes deregistering from SelectionChanged works, sometimes not.

And I'm unregistering/reregistering in a try/finally construct:

            this.SelectionChanged -= ManageSelectionChanged;

            try
            {
                // code that could fire this.SelectionChanged
            }
            finally
            {                    
                this.SelectionChanged += ManageSelectionChanged;                 
            }

I've choosen to use a private flag too, but... I'm still curious.