delphi在TMemo中实现高亮文字

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delphi在TMemo中实现高亮文字
在memo中实现类似IDE的效果，对数字及自定义的关键字高亮显示，并自定义关键字

unit Unit1;

 

interface

 

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;

type

  TMemo = class(stdctrls.TMemo)

  private

    procedure WMPaint(var Message: TWMPaint); message WM_PAINT;

    procedure WMSize(var Message: TWMSize); message WM_SIZE;

    procedure WMMove(var Message: TWMMove); message WM_MOVE;

    procedure WMVScroll(var Message: TWMMove); message WM_VSCROLL;

    procedure WMMousewheel(var Message: TWMMove); message WM_MOUSEWHEEL;

  protected

    procedure Change; override;

    procedure KeyDown(var Key: Word; Shift: TShiftState); override;

    procedure KeyUp(var Key: Word; Shift: TShiftState); override;

    procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

      override;

    procedure MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

      override;

  public

    PosLabel: TLabel;

    procedure Update_label;

    procedure GotoXY(mCol, mLine: Integer);

    function Line: Integer;

    function Col: Integer;

    function TopLine: Integer;

    function VisibleLines: Integer;

  end;

type

  TForm1 = class(TForm)

    Label1: TLabel;

    GroupBox1: TGroupBox;

    KeywordList: TListBox;

    GroupBox2: TGroupBox;

    GroupBox3: TGroupBox;

    Memo1: TMemo;

    Label2: TLabel;

    procedure FormCreate(Sender: TObject);

    procedure FormClose(Sender: TObject; var Action: TCloseAction);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

 

var

  Form1: TForm1;

 

implementation

 

{$R *.dfm}

//分隔符，如有特殊需要自己添加

function IsSeparator(Car: Char): Boolean;

begin

  case Car of

    '.', ';', ',', ':', '?', '!', '"', '''',' ', '^', '+', '-', '*', '/', '\', '`', '[', ']', '(', ')', 'o', 'a', '{', '}', '%', '=': Result := True;

  else

    Result := False;

  end;

end;

////////////////////////////////////////////////////////////////////////////////

 

function NextWord(var s: string; var PrevWord: string): string;

begin

  Result := '';

  PrevWord := '';

  if s = '' then Exit;

  while (s <> '') and IsSeparator(s[1]) do

  begin

    PrevWord := PrevWord + s[1];

    Delete(s, 1, 1);

  end;

  while (s <> '') and not IsSeparator(s[1]) do

  begin

    Result := Result + s[1];

    Delete(s, 1, 1);

  end;

end;

////////////////////////////////////////////////////////////////////////////////

 

function IsKeyWord(s: string): Boolean;

begin

  Result := False;

  if s = '' then Exit;

  Result := Form1.KeywordList.Items.IndexOf(lowercase(s)) <> -1;

end;

////////////////////////////////////////////////////////////////////////////////

 

function IsNumber(s: string): Boolean;

var

  i: Integer;

begin

  Result := False;

  for i := 1 to Length(s) do

    case s[i] of

      '0'..'9': ;

    else

      Exit;

    end;

  Result := True;

end;

////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////

// New or overrided methods and properties for TMemo using Interjected Class ///

// Technique ///////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////

 

function TMemo.VisibleLines: Integer;

begin

  Result := Height div (Abs(Self.Font.Height) + 2);

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.GotoXY(mCol, mLine: Integer);

begin

  Dec(mLine);

  SelStart := 0;

  SelLength := 0;

  SelStart := mCol + Self.Perform(EM_LINEINDEX, mLine, 0);

  SelLength := 0;

  SetFocus;

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.Update_label;

begin

  if PosLabel = nil then Exit;

  PosLabel.Caption := '(' + IntToStr(Line + 1) + ',' + IntToStr(Col) + ')';

end;

////////////////////////////////////////////////////////////////////////////////

 

function TMemo.TopLine: Integer;

begin

  Result := SendMessage(Self.Handle, EM_GETFIRSTVISIBLELINE, 0, 0);

end;

////////////////////////////////////////////////////////////////////////////////

 

function TMemo.Line: Integer;

begin

  Result := SendMessage(Self.Handle, EM_LINEFROMCHAR, Self.SelStart, 0);

end;

////////////////////////////////////////////////////////////////////////////////

 

function TMemo.Col: Integer;

begin

  Result := Self.SelStart - SendMessage(Self.Handle, EM_LINEINDEX,

    SendMessage(Self.Handle,

    EM_LINEFROMCHAR, Self.SelStart, 0), 0);

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.WMVScroll(var Message: TWMMove);

begin

  Update_label;

  Invalidate;

  inherited;

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.WMSize(var Message: TWMSize);

begin

  Invalidate;

  inherited;

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.WMMove(var Message: TWMMove);

begin

  Invalidate;

  inherited;

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.WMMousewheel(var Message: TWMMove);

begin

  Invalidate;

  inherited;

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.Change;

begin

  Update_label;

  Invalidate;

  inherited Change;

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.KeyDown(var Key: Word; Shift: TShiftState);

begin

  Update_label;

  inherited KeyDown(Key, Shift);

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.KeyUp(var Key: Word; Shift: TShiftState);

begin

  Update_label;

  inherited KeyUp(Key, Shift);

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

begin

  Update_label;

  inherited MouseDown(Button, Shift, X, Y);

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

begin

  Update_label;

  inherited MouseUp(Button, Shift, X, Y);

end;

////////////////////////////////////////////////////////////////////////////////

 

procedure TMemo.WMPaint(var Message: TWMPaint);

var

  PS: TPaintStruct;

  DC: HDC;

  Canvas: TCanvas;

  i: Integer;

  X, Y: Integer;

  OldColor: TColor;

  Size: TSize;

  Max: Integer;

  s, Palabra, PrevWord: string;

begin

  DC := Message.DC;

  if DC = 0 then DC := BeginPaint(Handle, PS);

  Canvas := TCanvas.Create;

  try

    OldColor := Font.Color;

    Canvas.Handle := DC;

    Canvas.Font.Name := Font.Name;

    Canvas.Font.Size := Font.Size;

    with Canvas do

    begin

      Max := TopLine + VisibleLines;

      if Max > Pred(Lines.Count) then Max := Pred(Lines.Count);

 

      //Limpio la sección visible

      Brush.Color := Self.Color;

      FillRect(Self.ClientRect);

      Y := 1;

      for i := TopLine to Max do

      begin

        X := 2;

        s := Lines[i];

 

        //Detecto todas las palabras de esta línea

        Palabra := NextWord(s, PrevWord);

        while Palabra <> '' do

        begin

          Font.Color := OldColor;

          TextOut(X, Y, PrevWord);

          GetTextExtentPoint32(DC, PChar(PrevWord), Length(PrevWord), Size);

          Inc(X, Size.cx);

 

          Font.Color := clBlack;

          if IsKeyWord(Palabra) then

          begin

            Font.Color := clHighlight;

 

            TextOut(X, Y, Palabra);

             {

             //Draw dot underline

             Pen.Color := clHighlight;

             Pen.Style := psDot;

             PolyLine([ Point(X,Y+13), Point(X+TextWidth(Palabra),Y+13)]);

             }

          end

          else if IsNumber(Palabra) then

          begin

            Font.Color := $000000DD;

            TextOut(X, Y, Palabra);

          end

          else

          begin

 

            TextOut(X, Y, Palabra);

           end;

          GetTextExtentPoint32(DC, PChar(Palabra), Length(Palabra), Size);

          Inc(X, Size.cx);

 

          Palabra := NextWord(s, PrevWord);

          if (s = '') and (PrevWord <> '') then

          begin

            Font.Color := OldColor;

            TextOut(X, Y, PrevWord);

          end;

        end;

        if (s = '') and (PrevWord <> '') then

        begin

          Font.Color := OldColor;

          TextOut(X, Y, PrevWord);

        end;

 

        s := 'W';

        GetTextExtentPoint32(DC, PChar(s), Length(s), Size);

        Inc(Y, Size.cy);

      end;

    end;

  finally

    if Message.DC = 0 then EndPaint(Handle, PS);

  end;

  Canvas.Free;

  inherited;

end;

 

procedure TForm1.FormCreate(Sender: TObject);

begin

  Memo1.PosLabel := Label1;

  Memo1.Update_label;

end;

 

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);

begin

  Action := caFree;

end;

 

end.