Delphi OpenDialog使用方法

var  OpenDlg: TOpenDialog;  strFileName: string;begin  OpenDlg := TOpenDialog.Create(nil);  try    OpenDlg.Filter := '协议文件(*.EXE)|*.EXE|全部文件(*.*)|*.*';    OpenDlg.DefaultExt := '*.EXE';    if OpenDlg.Execute then    begin      strFileName := Trim(OpenDlg.FileName);      if strFileName <> '' then      begin        edtProtocolApplication.Text := strFileName;      end;    end;  finally    FreeAndNil(OpenDlg);  end;end;