Checking if a datarowview is null?

Question

I'm facing an issue when trying to verify if a cell of a wpf datagrid is null, I always get a null reference exception even when I try to verify if it's null, can anyone help me here?

code bellow

for (int i = 0; i < commandeDataGrid.Items.Count; i++)
        {

            DataRowView row = commandeDataGrid.Items[i] as DataRowView;

            if (row["Prix Total TTC"]!=null)
            {
               count = count + Convert.ToInt16(row["Prix Total TTC"]);
            }

        }

Answer 1

You should check whether the as operator actually returns a DataRowView:

for (int i = 0; i < commandeDataGrid.Items.Count; i++)
{
    DataRowView row = commandeDataGrid.Items[i] as DataRowView;
    if (row != null && row["Prix Total TTC"] != null)
    {
        count = count + Convert.ToInt16(row["Prix Total TTC"]);
    }
}

Or better yet iterate through the ItemsSource:

DataView dataView = commandeDataGrid.ItemsSource as DataView;
if (dataView != null)
{
    foreach (DataRowView row in dataView)
    {
        if (row["Prix Total TTC"] != null)
        {
            count = count + Convert.ToInt16(row["Prix Total TTC"]);
        }
    }
}