Delphi操作RichEdit总结

发布: 2023-08-10 作者: admin 浏览: 74 评论: 0 分类: C++ 标签: RichEdit

uses RichEdit;

1. 设置RichEdit的行间距，代码如下
```cpp
	procedure TForm1.Button3Click(Sender: TObject);
	var
	  pf: PARAFORMAT2;
	begin
	  FillChar(pf, sizeof(paraformat2), #0);
	  pf.cbSize := SizeOf(paraformat2);
	  pf.dwMask := PFM_LINESPACING  ;   //需要设置上 PFM_LINESPACING 标志，bLineSpacingRule和dyLineSpacing才可能有效

//  pf.bLineSpacingRule := 0;   //单倍行距，dyLineSpacing的值将被忽略
	//  pf.bLineSpacingRule := 1;   //1.5倍行距，dyLineSpacing的值将被忽略
	//  pf.bLineSpacingRule := 2;   //两倍行距，dyLineSpacing的值将被忽略
	//  pf.bLineSpacingRule := 3;   //用dyLineSpacing以缇为单位指定行间距，当此值小于单倍行距时，效果为单倍行距
	//  pf.bLineSpacingRule := 5;   //用dyLineSpacing/20指定行间距

pf.bLineSpacingRule := 4;   //用dyLineSpacing以缇为单位指定行间距
	  pf.dyLineSpacing := RichEdit1.Font.Size * 20 + 20 * 4; //这是笔者大概计算的，可以根据字体大小调节的，行间最小距离，大字体时可能出现上下行重叠，可以设置为300或者自己计算

RichEdit1.SelectAll;   //只对选择的文本有效，***重要***
	  SendMessage(RichEdit1.Handle, EM_SETPARAFORMAT, 0, LPARAM(@pf));
	  RichEdit1.SelStart := 0;
	  RichEdit1.SelLength := 0;
	end;
```

------------

2. 为RichEdit设置行号，代码如下：
```cpp
	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;
```

------------

3. 根据鼠标位置定位光标的方法。
当RichEdit为可用状态时，是不用代码控制此操作的，TRichEdit本身就可以定位光标。但是当RichEdit开始不可用时，则此方法就可能用到了。本例中RichEdit1开始时是不可用的，当在ApplicationEvents1中接收到RichEdit1被双击时则设置RichEdit1的Enable := true;并且定位光标。
```cpp
	unit Unit1;

interface

uses
	  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
	  Dialogs, StdCtrls, ComCtrls, RichEdit, AppEvnts;

type
	  TForm1 = class(TForm)
		RichEdit1: TRichEdit;
		ApplicationEvents1: TApplicationEvents;
		procedure EnableRichEdit;
		procedure ApplicationEvents1Message(var Msg: tagMSG; var Handled: Boolean);
	  private
		{ Private declarations }
	  public
		{ Public declarations }
	  end;

var
	  Form1: TForm1;
	  FLastMousePos: TPoint;

implementation

{$R *.dfm}

procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG;
	  var Handled: Boolean);
	var
	  mPos: TPoint;
	begin
	  if msg.message = WM_LBUTTONDBLCLK then begin
		if msg.hwnd = RichEdit1.Parent.Handle then begin
		  GetCursorPos(FLastMousePos);
		  EnableRichEdit;
		end;
	  end ;
	end;

procedure TForm1.EnableRichEdit;
	var
	  cPos: TPoint;
	  retCode: integer;
	  mR, mC: Word;
	begin
	  RichEdit1.Enabled := True;
	  RichEdit1.SetFocus ;
	  RichEdit1.SelStart := 0;

if (FLastMousePos.X = 0) and (FLastMousePos.Y = 0) then
		GetCursorPos(FLastMousePos);
	  FLastMousePos := RichEdit1.ScreenToClient(FLastMousePos);
	  retCode := SendMessage(RichEdit1.Handle, EM_CHARFROMPOS, 0, LPARAM(@FLastMousePos));
	  mR := HiWord(retCode);
	  mC := Loword(retCode);
	  cPos.X := mC ;
	  cPos.Y := mR ;
	  RichEdit1.CaretPos := cPos;

FLastMousePos.X := 0;
	  FLastMousePos.Y := 0;
	end;

end.
```

------------

4. 使Richedit中的链接可以点击
```cpp
	unit Unit1;

interface

uses
	  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
	  Dialogs, StdCtrls, ComCtrls, RichEdit, ShellAPI;

type
	  TForm1 = class(TForm)
		RichEdit1: TRichEdit;
		procedure FormCreate(Sender: TObject);
	  private
		{ Private declarations }
	  public
		procedure WndProc(var Msg: TMessage); override;
	  end;

var
	  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
	var
	  mask: Word;
	begin
	  mask := SendMessage(RichEdit1.Handle, EM_GETEVENTMASK, 0, 0);
	  SendMessage(RichEdit1.Handle, EM_SETEVENTMASK, 0, mask or ENM_LINK);
	  SendMessage(RichEdit1.Handle, EM_AUTOURLDETECT, Integer(True), 0);
	end;

procedure TForm1.WndProc(var Msg: TMessage);
	var
	  p: TENLink;
	  sURL: string;
	  CE : TRichEdit;
	begin
	  if (Msg.Msg = WM_NOTIFY) then
	  begin
		if (PNMHDR(Msg.lParam).code = EN_LINK) then
		begin
		  p := TENLink(Pointer(TWMNotify(Msg).NMHdr)^);
		  if (p.Msg = WM_LBUTTONDOWN) then
		  begin
			try
			  CE := tRichEdit(Self.ActiveControl);
			  SendMessage(CE.Handle, EM_EXSETSEL, 0, Longint(@(p.chrg)));
			  sURL := CE.SelText;
			  ShellExecute(0, 'open', PChar(sURL), 0, 0, SW_SHOWNORMAL);
			except
			end;
		  end;
		end;
	  end;
	  inherited;
	end;

end.
```