怎么样才能使 richedit 透明? 100 分

[manjel]

如题

[manjel]

下面的代码是我抄来的.它实现了 memo 的透明效果 直接把 Tmemo 换成 Trichedit 也能透明
可惜的是不能显示文本.不知道那位大侠能帮帮小弟.不胜感激.


TTransMemo = class(Tmemo)
private
FAlignText: TAlignment;
FTransparent: Boolean;
FPainting: Boolean;
procedure SetAlignText(Value: TAlignment);
procedure SetTransparent(Value: Boolean);
procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
procedure WMNCPaint (var Message: TMessage); message WM_NCPAINT;
procedure WMEraseBkGnd(var Message: TWMEraseBkGnd); message WM_ERASEBKGND;
procedure CNCtlColorEdit(var Message: TWMCtlColorEdit); message CN_CTLCOLOREDIT;
procedure CNCtlColorStatic(var Message: TWMCtlColorStatic); message CN_CTLCOLORSTATIC;
procedure CMParentColorChanged(var Message: TMessage); message CM_PARENTCOLORCHANGED;
procedure WMSize(var Message: TWMSize); message WM_SIZE;
procedure WMMove(var Message: TWMMove); message WM_MOVE;
protected
procedure RepaintWindow;
procedure CreateParams(var Params: TCreateParams); override;
procedure Change; override;
procedure SetParent(AParent: TWinControl); override;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
published
property AlignText: TAlignment read FAlignText write SetAlignText default taLeftJustify;
property Transparent: Boolean read FTransparent write SetTransparent default false;
end;

// Transparent Memo
constructor TTransMemo.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FAlignText := taLeftJustify;
FTransparent := false;
FPainting := false;
end;

destructor TTransMemo.Destroy;
begin
inherited Destroy;
end;

procedure TTransMemo.SetAlignText(Value: TAlignment);
begin
if FAlignText <> Value then
begin
FAlignText := Value;
RecreateWnd;
Invalidate;
end;
end;

procedure TTransMemo.SetTransparent(Value: Boolean);
begin
if FTransparent <> Value then
begin
FTransparent := Value;
Invalidate;
end;
end;

procedure TTransMemo.WMEraseBkGnd(var Message: TWMEraseBkGnd);
var
DC: hDC;
i: integer;
p: TPoint;
begin
if FTransparent then
begin
if Assigned(Parent) then
begin
DC := Message.DC;
i := SaveDC(DC);
p := GetScreenClient(self);
p.x := -p.x;
p.y := -p.y;
MoveWindowOrg(DC, p.x, p.y);
SendMessage(Parent.Handle, $0014, DC, 0);
TCtrl(Parent).PaintControls(DC, nil);
RestoreDC(DC, i);
end;
end else inherited;
end;

procedure TTransMemo.WMPaint(var Message: TWMPaint);
begin
inherited;
if FTransparent then
if not FPainting then
RepaintWindow;
end;

procedure TTransMemo.WMNCPaint(var Message: TMessage);
begin
inherited;
end;

procedure TTransMemo.CNCtlColorEdit(var Message: TWMCtlColorEdit);
begin
inherited;
if FTransparent then
SetBkMode(Message.ChildDC, 1);
end;

procedure TTransMemo.CNCtlColorStatic(var Message: TWMCtlColorStatic);
begin
inherited;
if FTransparent then
SetBkMode(Message.ChildDC, 1);
end;

procedure TTransMemo.CMParentColorChanged(var Message: TMessage);
begin
inherited;
if FTransparent then
Invalidate;
end;

procedure TTransMemo.WMSize(var Message: TWMSize);
begin
inherited;
Invalidate;
end;

procedure TTransMemo.WMMove(var Message: TWMMove);
begin
inherited;
Invalidate;
end;

procedure TTransMemo.RepaintWindow;
var
DC: hDC;
TmpBitmap, Bitmap: hBitmap;
begin
if FTransparent then
begin
FPainting := true;
HideCaret(Handle);
DC := CreateCompatibleDC(GetDC(Handle));
TmpBitmap := CreateCompatibleBitmap(GetDC(Handle), Succ(ClientWidth), Succ(ClientHeight));
Bitmap := SelectObject(DC, TmpBitmap);
PaintTo(DC, 0, 0);
BitBlt(GetDC(Handle), BorderRec[BorderStyle], BorderRec[BorderStyle], ClientWidth, ClientHeight, DC, 1, 1, SRCCOPY);
SelectObject(DC, Bitmap);
DeleteDC(DC);
ReleaseDC(Handle, GetDC(Handle));
DeleteObject(TmpBitmap);
ShowCaret(Handle);
FPainting := false;
end;
end;

procedure TTransMemo.CreateParams(var Params: TCreateParams);
const
Alignments: array [TAlignment] of DWord = (ES_LEFT, ES_RIGHT, ES_CENTER);
begin
inherited CreateParams(Params);
Params.Style := Params.Style or ES_MULTILINE or Alignments[FAlignText];
end;

procedure TTransMemo.Change;
begin
RepaintWindow;
inherited Change;
end;

procedure TTransMemo.SetParent(AParent: TWinControl);
begin
inherited SetParent(AParent);
end;

[pankun]

转一个文章,可能对你有帮助

核心API函数就是SetLayeredWindowAttributes，以下的控件
代码是让你的窗口实现淡入淡出效果而设计，通过编程时动态改变AlphaValue值，您就
可以看到效果了。

unit TranForm; {DragonPC 2001.2.21 }

interface

uses

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs;

type

TTranForm = class(TComponent)

private

FAlphaValue : integer ;

FHandle : HWND ;

procedure SetFAlphaValue(Alpha:integer) ;

protected

procedure UpdateDisplay ;

public

constructor Create(AOwner: TComponent); override;

published

property AlphaValue : integer read FAlphaValue write SetFAlphaValue ;

end;

procedure Register;

function SetLayeredWindowAttributes

(Handle : HWND; COLORKEY : COLORREF; Alpha : BYTE; Flags : DWORD) :

Boolean;

stdcall; external 'USER32.DLL';

implementation

procedure Register;

begin

RegisterComponents('Standard', [TTranForm]);

end;

{ TTranForm }

procedure TTranForm.SetFAlphaValue(Alpha: integer);

begin

if (Alpha >= 0) and (Alpha < 256) then begin

FAlphaValue := Alpha ;

UpdateDisplay() ;

end else

ShowMessage('请输入0~255之间的值！') ;

end;

procedure TTranForm.UpdateDisplay;

begin

if not (csDesigning in ComponentState) then

SetLayeredWindowAttributes(FHandle, 0, FAlphaValue, 2);


end;

constructor TTranForm.Create(AOwner: TComponent);

begin

inherited;

FAlphaValue := 255 ;

FHandle := TForm(Owner).Handle ;

if not (csDesigning in ComponentState) then

SetWindowLong(FHandle,GWL_EXSTYLE, GetWindowLong(FHandle, GWL_EXSTYLE )

or $80000 );

{我屏蔽了设计期的显示效果，如果你愿意可以改改，建议设计时最好不要看到效果}

end;

end.

**************

const

WS_EX_LAYERED = $80000;

AC_SRC_OVER = $0;

AC_SRC_ALPHA = $1;

AC_SRC_NO_PREMULT_ALPHA = $1;

AC_SRC_NO_ALPHA = $2;

AC_DST_NO_PREMULT_ALPHA = $10;

AC_DST_NO_ALPHA = $20;

LWA_COLORKEY = $1;

LWA_ALPHA = $2;

ULW_COLORKEY = $1

ULW_ALPHA = $2

ULW_OPAQUE = $4

//新增加的常量定义

function SetLayeredWindowAttributes(hwnd:HWND; crKey:Longint; bAlpha:byte; dwFlags:longint ):longint; stdcall; external user32;//函数声明

　

procedure TForm1.FormCreate(Sender: TObject);

var l:longint;

begin

l:=getWindowLong(Handle, GWL_EXSTYLE);

l := l Or WS_EX_LAYERED;

SetWindowLong (handle, GWL_EXSTYLE, l);

SetLayeredWindowAttributes (handle, 0, 180, LWA_ALPHA);

//第二个参数是指定透明颜色

//第二个参数为0则使用第四个参数设置alpha值，从0到255，

end;

[manjel]

谢谢你 pankun(剑神一笑).

但它似乎只对窗口有效.不能用在 richedit上啊.

[manjel]

转贴---------------------------------------


type
TForm1 = class(TForm)
Image1: TImage;
BitBtn1: TBitBtn;
RichEdit1: TRichEdit;
procedure ClassWndProc(var Msg: TMessage);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public

{ Public declarations }
end;

var

Form1: TForm1;
wproc: pointer;
oldproc:TWndMethod;
bb:hBrush ;
implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
oldproc:=RichEdit1.WindowProc;
RichEdit1.WindowProc:=form1.ClassWndProc;
SetWindowLong(RichEdit1.Handle, GWL_EXSTYLE, GetWindowLong(RichEdit1.Handle,GWL_EXSTYLE) or WS_EX_TRANSPARENT);
end;


procedure Tform1.ClassWndProc(var Msg: TMessage);
begin
if msg.Msg= WM_ERASEBKGND then
msg. result:=1 else
if (msg.Msg = CN_CTLCOLORMSGBOX )or(msg.Msg = CN_CTLCOLORSTATIC ) then
begin
bb:=null;
msg. result :=bb
end else
oldproc(msg)
end;