title: C# how to set dropDownList default value for selectedValue = null
body: <p>I have a <code>dropdownlist1</code> that has has 6 collection items including <code>Select One</code>. What I want is this ddl is set to <code>Selectedvalue</code> = null. But what I am getting is my ddl always selecting <code>Select One</code> as its initial value. My ddl properties for <code>Select One</code> is selected:false. How to set this ddl to initial selected value = null?</p>
  
  <pre><code>&lt;asp:DropDownList ID="DropDownList1" runat="server" Visible="False" Width="146px"&gt;
       &lt;asp:ListItem&gt;Ceiling Speaker&lt;/asp:ListItem&gt;
       &lt;asp:ListItem&gt;Remote Microphone&lt;/asp:ListItem&gt;
       &lt;asp:ListItem&gt;Digital Source Player&lt;/asp:ListItem&gt;
       &lt;asp:ListItem&gt;Remote paging Console&lt;/asp:ListItem&gt;
       &lt;asp:ListItem&gt;Modular Mixer&lt;/asp:ListItem&gt;
       &lt;asp:ListItem&gt;Select One&lt;/asp:ListItem&gt;
  &lt;/asp:DropDownList&gt;
  
  
  if (String.IsNullOrEmpty(txtSearchProductname.Text))
  {
     if (DropDownList1.SelectedValue == null)
     {
         txtProductName.Text = "";
     }
     else
     {
         SqlProductmaster.InsertParameters["ProductName"].DefaultValue = DropDownList1.SelectedValue.ToString();
     }
  }
  else
  {
      SqlProductmaster.InsertParameters["ProductName"].DefaultValue = txtProductName.Text;
  }
  </code></pre>