(Asp.net c #) Two Methods for displaying corresponding items after DropDownList is bound

Method 1:

Implementation CodeCopy codeThe Code is as follows: DropDownList1.DataSource = listSort;
DropDownList1.DataTextField = "LogSortName ";
DropDownList1.DataValueField = "LogSortID ";
DropDownList1.DataBind ();
DropDownList1.SelectedIndex = ddl. Items. IndexOf (DropDownList1.Items. FindByValue ("I "));
// I need to obtain the id of the item you want to display by myself.

Method 2: I pasted some code

After obtaining the data, pair the items you want based on the value.

But the for in the figure is changed to do... While should be easier.
In fact, both methods have the same idea. They all use id pairs...