我希望对 Delphi 7 中的透明 TMemo 控件有所帮助。我在网上找到了一些运行良好的代码,在某种程度上,刷新率有点垃圾,但我可以忍受。主要问题是未选择的文本看起来好像它实际上已被选中。
这是使用 SelectAll() 选择所有文本的地方;
这里实际上没有选择文本,但之前已经选择了,请注意浮线表示输入将发生在改进中的“p”之后。
最后是一张显示差异的图像。
我觉得很奇怪的是,例如,如果我按箭头键,错误的突出显示就会消失,但使用鼠标时却不会。
这个自定义 TMemo 的代码如下:
unit TrMemo;
interface
uses
Messages, Controls, StdCtrls, classes;
const TMWM__SpecialInvalidate=WM_USER+1111;
type
TTransparentMemo = class(TMemo)
private
procedure SpecialInvalidate(var Message:TMessage); message TMWM__SpecialInvalidate;
procedure WMHScroll(var Message: TWMHScroll); message WM_HSCROLL;
procedure WMVScroll(var Message: TWMVScroll); message WM_VSCROLL;
procedure WMSetText(var Message:TWMSetText); message WM_SETTEXT;
procedure CNCTLCOLOREDIT(var Message:TWMCTLCOLOREDIT); message CN_CTLCOLOREDIT;
procedure WMKeyDown(var Message: TWMKeyDown); message WM_KEYDOWN;
procedure WMEraseBkgnd(var Message: TWMEraseBkgnd); message WM_ERASEBKGND;
protected
procedure CreateParams(var Params: TCreateParams); override;
public
constructor Create(AOwner: TComponent); override;
end;
procedure Register;
implementation
uses Windows;
{ TTransparentMemo }
procedure TTransparentMemo.WMHScroll(var Message: TWMHScroll);
begin
inherited;
PostMessage(Handle,TMWM__SpecialInvalidate,0,0);
end;
procedure TTransparentMemo.WMVScroll(var Message: TWMVScroll);
begin
SendMessage(Handle,TMWM__SpecialInvalidate,0,0);
inherited;
PostMessage(Handle,TMWM__SpecialInvalidate,0,0);
end;
procedure TTransparentMemo.CNCTLCOLOREDIT(var Message:TWMCTLCOLOREDIT);
begin
with Message do
begin
SetBkMode(ChildDC,TRANSPARENT);
Result:=GetStockObject(HOLLOW_BRUSH)
end
end;
procedure TTransparentMemo.WMSetText(var Message:TWMSetText);
begin
inherited;
if not (csDesigning in ComponentState) then PostMessage(Handle,TMWM__SpecialInvalidate,0,0)
end;
procedure TTransparentMemo.SpecialInvalidate(var Message:TMessage);
var
r:TRect;
begin
if (Parent <> nil) then
begin
r:=ClientRect;
r.TopLeft:=Parent.ScreenToClient(ClientToScreen(r.TopLeft));
r.BottomRight:=Parent.ScreenToClient(ClientToScreen(r.BottomRight));
InvalidateRect(Parent.Handle,@r,true);
RedrawWindow(Handle,nil,0,RDW_FRAME+RDW_INVALIDATE);
end;
end;
procedure TTransparentMemo.WMKeyDown(var Message: TWMKeyDown);
begin
SendMessage(Handle,TMWM__SpecialInvalidate,0,0);
inherited;
PostMessage(Handle,TMWM__SpecialInvalidate,0,0);
end;
procedure TTransparentMemo.WMEraseBkgnd(var Message: TWMEraseBkgnd);
begin
Message.Result:=1
end;
constructor TTransparentMemo.Create(AOwner: TComponent);
begin
inherited;
ControlStyle:=[csCaptureMouse, csDesignInteractive, csClickEvents, csSetCaption, csOpaque, csDoubleClicks, csReplicatable, csNoStdEvents];
end;
procedure TTransparentMemo.CreateParams(var Params: TCreateParams);
begin
inherited CreateParams(Params);
with Params do
begin
ExStyle:=ExStyle or WS_EX_TRANSPARENT and not WS_EX_WINDOWEDGE
and not WS_EX_STATICEDGE and not WS_EX_DLGMODALFRAME and not
WS_EX_CLIENTEDGE;
end;
end;
procedure Register;
begin
RegisterComponents('Samples', [tTransparentMemo]);
end;
end.
任何提示/提示/答案将不胜感激!提前干杯!