title: Selected Text of The ComboBox
body: <p>how can I get the selected text on the SelectionChanged event of the comboBox
  here is my code</p>
  
  <pre><code>&lt;ComboBox x:Name="cboRecordType" Margin="2,0" Height="23" Grid.Column="1" VerticalAlignment="Center" SelectionChanged="ComboBox_SelectionChanged"&gt;
              &lt;ComboBoxItem Content="Weight"/&gt;
              &lt;ComboBoxItem Content="Height"/&gt;
              &lt;ComboBoxItem Content="Blood Pressure"/&gt;
              &lt;ComboBoxItem Content="Blood Gulocose"/&gt;
          &lt;/ComboBox&gt;
  </code></pre>
  
  <p>cboRecordType.Text is empty, didn't cantain the selected Text, how to get that</p>