How to loop through multiple comboboxes for initial value in wpf

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C#

WPF

Hi all,

Can anybodytell me how to loop through multiple comboboxes added on a form grid & check for their initial values in wpf. If the initial value of any of the combobox is null then i should pop up a message.

I tried this, but i get error in the foreach expression:

foreach (Control c in this.Controls)
               {
                   if (c is ComboBox)
                   {
                       ComboBox textBox = c as ComboBox;
                       if (textBox.SelectedValue == null)
                       {
                           MessageBox.Show("please fill all fields");
                           break;
                       }
                   }
               }

Thanks in advance.