how to set the default value to the drop down list control?

Question

I have a drop down list control on my web page. I have bind the datatable to the dropdownlist control as follows -

lstDepartment.DataTextField = "DepartmentName";
    lstDepartment.DataValueField = "DepartmentID";
    lstDepartment.DataSource = dtDept;
    lstDepartment.DataBind();

in the page load event i want to set the default value to the drop down list control from my other table field.

how to do this?

Answer 1

After your DataBind():

lstDepartment.SelectedIndex = 0;  //first item

or

lstDepartment.SelectedValue = "Yourvalue"

or 
//add error checking, just an example, FindByValue may return null
lstDepartment.Items.FindByValue("Yourvalue").Selected = true;

or
//add error checking, just an example, FindByText may return null
lstDepartment.Items.FindByText("Yourvalue").Selected = true;

Answer 2

if you know the index of the item of default value,just

lstDepartment.SelectedIndex = 1;//the second item

or if you know the value you want to set, just

lstDepartment.SelectedValue = "the value you want to set";