Need generic utility C# method for populating ASP.NET DropDownList

Question

I have a method like the following in a utility class. I would like to change the parameter dataSource to accept any type of data source, that is, DataSet, DataView, List<T>, DataTable, and ArrayList.

Is this possible? How would I change the method signature (and parameters and types) to allow me the flexibility of passing in any acceptable datasource for binding?

public void FillCombo(DropDownList ddl, DataTable dataSource, string textField, string valueField, bool addSelect) {
    ddl.DataValueField = valueField;
    ddl.DataTextField = textField;
    ddl.DataSource = dataSource;
    ddl.DataBind();
    if (addSelect) 
        AddSelectCombo(ddl, "Select", -1);
}

Answer 1

Well, since the DataSource property on a DropDownList has type object you could change your method signature to accept an object. That would not make your method generic (in the .NET sense), but maybe it would be enough anyway.

Answer 2

I believe the following is what you're looking for.

public void FillCombo<TSource>(DropDownList ddl, TSource dataSource, string textField, string valueField, bool addSelect) {

    ddl.DataValueField = valueField;
    ddl.DataTextField = textField;
    ddl.DataSource = dataSource;
    ddl.DataBind();

    if (addSelect) AddSelectCombo(ddl, "Select", -1);

}