如何过滤ShellListView(50分)

如何过滤ShellListView,让它显示某种规定的文件类型

procedure TForm1.shViewAddFolder(Sender: TObject; AFolder: TShellFolder;<br>&nbsp; var CanAdd: Boolean);<br>var<br>&nbsp; s:string;<br>begin<br>&nbsp; s:=copy(afolder.PathName,length(afolder.PathName)-2,length(afolder.PathName));<br>&nbsp; if UpperCase(s)='EXE' then<br>&nbsp; &nbsp; canadd:=true<br>&nbsp; else<br>&nbsp; &nbsp; canadd:=false;<br>end;