How to fill DropDownList Dinamyc

How to fill DropDownList Dinamyc

I have some Asp.net dropdownList control, List docs have 3 properties :
DocID , UniqueIdentifier, Name. How to fill DDL only with this record
which goes across "IF" condition. It's a pseudo code.
List<IR_DocumentType> docs = IR_DocumentType.getDocType();
foreach (IR_DocumentType item in docs)
{
if (item.DocID ==1)
{
}
}
//dropdownList
DDL.DataSoure = docs;
DDL.Bind();