Delphi自写组件:可设置颜色的按钮(改成BS_OWNERDRAW风格,然后CN_DRAWITEM)

时间:2021-02-12 21:05:40
unit ColorButton;

interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls,
StdCtrls;
type
TColorButton = class(TButton)
private
//添加Color属性,默认clWhite
{ Private declarations }
FColor:TColor;
FCanvas:TCanvas;
IsFocused:Boolean;
procedure SetColor(Value:Tcolor);
procedure CNDrawItem(var Message:TWMDrawItem);message CN_DRAWITEM;
protected
{ Protected declarations }
procedure CreateParams(var Params:TCreateParams);override;
procedure SetButtonStyle(ADefault:Boolean);override;
public
{ Public declarations }
constructor Create(AOwner:TComponent);override;
destructor Destroy;override;
published
{ Published declarations }
property Color:TColor read FColor write SetColor default clWhite;
end; procedure Register; implementation
//**********************************
//*** Borland/Delphi7/Source/Vcl/checklst.pas 可做参考
//**********************************
//系统自动添加的注册函数
procedure Register;
begin
RegisterComponents('Additional', [TColorButton]);
end;
//*********添加构造函数***************
constructor TColorButton.Create(AOwner:TComponent);
begin
inherited Create(AOwner);
FCanvas:=TCanvas.Create;
FColor:=clWhite; //设置默认颜色
end;
//*********添加析构函数***************
destructor TColorButton.Destroy;
begin
FCanvas.Free;
inherited Destroy;
end;
//****定义按钮样式,必须将该按钮重定义为自绘式按钮*****
procedure TColorButton.CreateParams(var Params:TCreateParams);
begin
inherited CreateParams(Params);
with Params do Style:=Style or BS_OWNERDRAW;
end;
//****属性写方法*****
procedure TColorButton.SetColor(Value:TColor);
begin
FColor:=Value;
Invalidate; //完全重画控件
end;
//****设置按钮状态*****
procedure TColorButton.SetButtonStyle(ADefault:Boolean);
begin
if ADefault<>IsFocused then
begin
IsFocused:=ADefault;
Refresh;
end;
end;
//****绘制按钮*****
procedure TColorButton.CNDrawItem(var Message: TWMDrawItem);
var
IsDown,IsDefault:Boolean;
ARect:TRect;
Flags:Longint;
DrawItemStruct:TDrawItemStruct;
wh:TSize;
begin
/////////////////////////////////////////
DrawItemStruct:=Message.DrawItemStruct^;
FCanvas.Handle := DrawItemStruct.hDC;
ARect := ClientRect;
with DrawItemStruct do
begin
IsDown := itemState and ODS_SELECTED <> ;
IsDefault := itemState and ODS_FOCUS <> ;
end;
Flags := DFCS_BUTTONPUSH or DFCS_ADJUSTRECT;
if IsDown then Flags := Flags or DFCS_PUSHED;
if DrawItemStruct.itemState and ODS_DISABLED <> then
Flags := Flags or DFCS_INACTIVE;
if IsFocused or IsDefault then
begin
//按钮得到焦点时的状态绘制
FCanvas.Pen.Color := clWindowFrame;
FCanvas.Pen.Width := ;
FCanvas.Brush.Style := bsClear;
FCanvas.Rectangle(ARect.Left, ARect.Top, ARect.Right, ARect.Bottom);
InflateRect(ARect, -, -);
end;
FCanvas.Pen.Color := clBtnShadow;
FCanvas.Pen.Width := ;
FCanvas.Brush.Color := FColor;
if IsDown then begin
//按钮被按下时的状态绘制
FCanvas.Rectangle(ARect.Left , ARect.Top, ARect.Right, ARect.Bottom);
InflateRect(ARect, -, -);
end else
//绘制一个未按下的按钮
DrawFrameControl(DrawItemStruct.hDC, ARect, DFC_BUTTON, Flags);
FCanvas.FillRect(ARect);
//绘制Caption文本内容
FCanvas.Font := Self.Font;
ARect:=ClientRect;
wh:=FCanvas.TextExtent(Caption);
FCanvas.Pen.Width := ;
FCanvas.Brush.Style := bsClear;
if not Enabled then
begin //按钮失效时应多绘一次Caption文本
FCanvas.Font.Color := clBtnHighlight;
FCanvas.TextOut((Width div )-(wh.cx div )+,
(height div )-(wh.cy div )+,
Caption);
FCanvas.Font.Color := clBtnShadow;
end;
FCanvas.TextOut((Width div )-(wh.cx div ),(height div )-(wh.cy div ),Caption);
//绘制得到焦点时的内框虚线
if IsFocused and IsDefault then
begin
ARect := ClientRect;
InflateRect(ARect, -, -);
FCanvas.Pen.Color := clWindowFrame;
FCanvas.Brush.Color := FColor;
DrawFocusRect(FCanvas.Handle, ARect);
end;
FCanvas.Handle := ;
end;
end.

http://blog.csdn.net/aroc_lo/article/details/3070530

http://www.fx114.net/qa-183-149306.aspx