ASP.NET DropDownList Part 2: Setting Default Value on First Page Load

In part one DropDownList Part 1: Bind a DataTable to A DropDownList we learned how to bind a DataTable to a DropDownList.  In this tutorial we will learn to set the default value of the DropDownList control on the page's first load that is before there is a post back to the page.  This behavior is commonly used when you want to default the drop down list to a particular selection.  Such as the "United States" in a list of countries drop down list.

To set a default value in the DropDownList control follow the steps below.

1. Add the SetDefaultSelectItem method to the code behind file.

protected void SetDefaultSelectItem(string txtSelect)
{
   DropDownList1.Items.FindByText(txtSelect).Selected = true;
}

2. Add a condition to only set the default value on the first page load

protected void Page_Load(object sender, EventArgs e)
{
    if(!Page.IsPostBack)
    {
        BindCategoriesList();
        SetDefaultSelectItem("Seafood");
    }
}

3. If you run the application you will now see that "Seafood" is the default selection on the DropDownList control, when the page first load

1. Bind a DataTable To A DropDownList
2. (DropDownList) Setting Default Value on First Page Load
3. Use The DropDownList Control To Populate GridView
4. Bind DropDownList To A List Of Objects