procedure TForm1.Button4Click(Sender: TObject);

const

  PFNS_PAREN = $000;  //e.g. 1)

  PFNS_PARENS = $100;  //e.g. (1)

  PFNS_PERIOD = $200;  //e.g. 1.

  PFNS_PLAIN = $300;

  PFNS_NONUMBER = $400;

const

  PFN_NONE     = $00000000;  //无

  PFN_BULLET   = $00000001;  //黑色实心圆点

  PFN_ARABIC   = $00000002;  //0,1,2

  PFN_LCLETTER = $00000003;  //a,b,c

  PFN_UCLETTER = $00000004;  //A,B,C

  PFN_LCROMAN  = $00000005;  //i,ii,iii

  PFN_UCROMAN  = $00000006;  //I,II,III

  var

  pf: PARAFORMAT2;

begin

  FillChar(pf, sizeof(paraformat2), #0);

  pf.cbSize := SizeOf(paraformat2);

  //PFM_NUMBERING: wNumbering 值有效

  //PFM_NUMBERINGSTYLE: wNumberingStyle值有效

  //PFM_NUMBERINGSTART: wNumberingStart值有效

  //PFM_STARTINDENT: dxStartIndent值有效

  pf.dwMask := PFM_NUMBERING or PFM_NUMBERINGSTYLE or PFM_NUMBERINGSTART or PFM_STARTINDENT;//or PFM_OFFSET;

  pf.wNumberingStyle := PFNS_PERIOD;  //设置行号的样式，可以为“)”，“.”，“()”

  pf.wNumberingStart := 1;            //设置行号起始值

  pf.wNumbering := PFN_ARABIC;        //设置行号的格式，可以为阿拉伯数字或者英文字母等格式

  pf.dxStartIndent := 60;             //设置行首缩进值

  RichEdit1.SelectAll;

  SendMessage(RichEdit1.Handle, EM_SETPARAFORMAT, 0, LPARAM(@pf));

  RichEdit1.SelStart := 0;

  RichEdit1.SelLength := 0;

end;