TextBoxBase.TextChanged=”Cmb_OnTextChanged”
<ComboBox x:Name="cmb" Grid.Row="0" Grid.Column="0" IsEditable="True" IsTextSearchCaseSensitive="False" IsTextSearchEnabled="True" FontSize="30" TextBoxBase.TextChanged="Cmb_OnTextChanged">
private void Cmb_OnTextChanged(object sender, System.Windows.Controls.TextChangedEventArgs e)
{
}
https://www.cnblogs.com/Fred1987/p/5799209.html