Delphi Richedit代码语法加亮显示

procedure CodeColors(Form : TForm;Style : String; RichE : TRichedit;InVisible : Boolean);
const
  // symbols...
  CodeC1: array[0..20] of String = ('#','$','(',')','*',',',
          '.','/',':',';','[',']','{','}','<','>',
          '-','=','+','''','@');
  // reserved words...
  CodeC2: array[0..44] of String = ('and','as','begin',
          'case','char','class','const','downto',
          'else','end','except','finally','for',
          'forward','function','if','implementation','interface',
          'is','nil','or','private','procedure','public','raise',
          'repeat','string','to','try','type','unit','uses','var',
          'while','external','stdcall','do','until','array','of',
          'in','shr','shl','cos','div');
var
  FoundAt : LongInt;
  StartPos, ToEnd, i : integer;
  OldCap,T : String;
  FontC, BackC, C1, C2 ,C3 ,strC, strC1 : TColor;
begin
  OldCap := Form.Caption;
  with RichE do
  begin
    Font.Name := 'Courier New';
    Font.Size := 10;
    if WordWrap then WordWrap := false;
    SelectAll;
    SelAttributes.color := clBlack;
    SelAttributes.Style := [];
    SelStart := 0;
    if InVisible then
    begin
      Visible := False;
      Form.Caption := 'Executing Code Coloring...';
    end;
  end; 

  BackC := clWhite; FontC := clBlack;
  C1 := clBlack; C2 := clBlack; C3 := clBlack;
  strC := clBlue; strC1 := clSilver; 

  if Style = 'Twilight' then
  begin
    BackC := clBlack; FontC := clWhite;
    C1 := clLime; C2 := clSilver; C3 := clAqua;
    strC := clYellow; strC1 := clRed;
  end
  else
  if Style = 'Default' then
  begin
    BackC := clWhite; FontC := clBlack;
    C1 := clTeal; C2 := clMaroon; C3 := clBlue;
    strC := clMaroon; strC1 := clSilver;
  end
  else
  if Style = 'Ocean' then
  begin
    BackC := $00FFFF80; FontC := clBlack;
    C1 := clMaroon; C2 := clBlack; C3 := clBlue;
    strC := clTeal; strC1 := clBlack;
  end
  else
  if Style = 'Classic' then
  begin
    BackC := clNavy; FontC := clYellow;
    C1 := clLime; C2 := clSilver; C3 := clWhite;
    strC := clAqua; strC1 := clSilver;
  end
  else
  begin
    with RichE do
    begin
      T := '{'+Style+' = Invalid Style [Default,Classic,Twilight,Ocean] ONLY! }';
      Lines.Insert(0,T);
      StartPos := 0;
      ToEnd := Length(Text) - StartPos;
      FoundAt := FindText(T, StartPos, ToEnd, [stWholeWord]);
      SelStart := FoundAt;
      SelLength := Length(T);
      SelAttributes.Color := clRed;
      SelAttributes.Style := [fsBold];
      StartPos := 0;
      ToEnd := Length(Text) - StartPos;
      FoundAt := FindText('ONLY!', StartPos, ToEnd, [stWholeWord]);
      SelStart := FoundAt;
      SelLength := 4;
      SelAttributes.Color := clRed;
      SelAttributes.Style := [fsBold,fsUnderLine];
    end;
  end; 

  RichE.SelectAll;
  RichE.color := BackC;
  RichE.SelAttributes.color := FontC; 

  for i := 0 to 100 do
  begin
    with RichE do
    begin
      StartPos := 0;
      ToEnd := Length(Text) - StartPos;
      FoundAt := FindText(IntToStr(i), StartPos, ToEnd, [stWholeWord]);
      while (FoundAt <> -1) do
      begin
        SelStart := FoundAt;
        SelLength := Length(IntToStr(i));
        SelAttributes.Color := C1;
        SelAttributes.Style := [];
        StartPos := FoundAt + Length(IntToStr(i));
        FoundAt := FindText(IntToStr(i), StartPos, ToEnd, [stWholeWord]);
      end;
    end;
  end;
  for i := 0 to 20 do
  begin
    with RichE do
    begin
      StartPos := 0;
      ToEnd := Length(Text) - StartPos;
      FoundAt := FindText(CodeC1[i], StartPos, ToEnd, []);
      while (FoundAt <> -1) do
      begin
        SelStart := FoundAt;
        SelLength := Length(CodeC1[i]);
        SelAttributes.Color := C2;
        StartPos := FoundAt + Length(CodeC1[i]);
        FoundAt := FindText(CodeC1[i], StartPos, ToEnd, []);
      end;
    end;
  end;
  for i := 0 to 44 do
  begin
    with RichE do
    begin
      StartPos := 0;
      ToEnd := Length(Text) - StartPos;
      FoundAt := FindText(CodeC2[i], StartPos, ToEnd, [stWholeWord]);
      while (FoundAt <> -1) do
      begin
        SelStart := FoundAt;
        SelLength := Length(CodeC2[i]);
        SelAttributes.Color := C3;
        SelAttributes.Style := [fsBold];
        StartPos := FoundAt + Length(CodeC2[i]);
        FoundAt := FindText(CodeC2[i], StartPos, ToEnd, [stWholeWord]);
      end;
    end;
  end;
  Startpos := 0;
  with RichE do
  begin
    FoundAt := FindText('''', StartPos, Length(Text), []);
    while FoundAt <> -1 do
    begin
      SelStart := FoundAt;
      Startpos := FoundAt+1;
      FoundAt := FindText('''', StartPos, Length(Text), []);
      if FoundAt <> -1 then
      begin
        SelLength := (FoundAt - selstart)+1;
        SelAttributes.Style := [];
        SelAttributes.Color := strC;
        StartPos := FoundAt+1;
        FoundAt := FindText('''', StartPos, Length(Text), []);
      end;
    end;
  end; 

  Startpos := 0;
  with RichE do
  begin
    FoundAt := FindText('{', StartPos, Length(Text), []);
    while FoundAt <> -1 do
    begin
      SelStart := FoundAt;
      Startpos := FoundAt+1;
      FoundAt := FindText('}', StartPos, Length(Text), []);
      if FoundAt <> -1 then
      begin
        SelLength := (FoundAt - selstart)+1;
        SelAttributes.Style := [];
        SelAttributes.Color := strC1;
        StartPos := FoundAt+1;
        FoundAt := FindText('{', StartPos, Length(Text), []);
      end;
    end;
  end;   

  if InVisible then
  begin
    RichE.Visible := True;
    Form.Caption := OldCap;
  end;
  RichE.SelStart := 0;
end;

procedure TFrmain.BitBtn1Click(Sender: TObject);
begin
  CodeColors(Self, 'ss', RichEdit1, True);
end;