美化你的菜單
發(fā)表時(shí)間：2024-06-19 來(lái)源：明輝站整理相關(guān)軟件相關(guān)文章人氣：
[摘要]Windows下的很多程序都有十分漂亮的菜單，例如Windows“開始”菜單左方從上到下的長(zhǎng)條形的Windows Banner 又或者是向Word那樣在每一個(gè)菜單條左邊都有一個(gè)小圖標(biāo)，看到這些很Cool的菜單，你是否覺得自己的菜單顯得單調(diào)乏味呢？不需要第三方控件，利用Delphi就可以實(shí)現(xiàn)上面的功...
Windows下的很多程序都有十分漂亮的菜單，例如Windows“開始”菜單左方從上到下的長(zhǎng)條形的Windows Banner 又或者是向Word那樣在每一個(gè)菜單條左邊都有一個(gè)小圖標(biāo)，看到這些很Cool的菜單，你是否覺得自己的菜單顯得單調(diào)乏味呢？不需要第三方控件，利用Delphi就可以實(shí)現(xiàn)上面的功能。
如果要實(shí)現(xiàn)自定義菜單就需要在繪制菜單時(shí)改變菜單的大小以適應(yīng)在菜單上繪制圖形，然后再在上面繪制自己所需要的菜單效果。在Delphi中，每一個(gè)菜單項(xiàng)對(duì)應(yīng)一個(gè)TmenuItem控件，這類控件都有兩個(gè)事件：OnDrawItem和OnMeasureItem，要實(shí)現(xiàn)自定義菜單，首先要介紹一下這兩個(gè)事件：
OnMeasureItem事件的定義如下：
type TMenuMeasureItemEvent = procedure (Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer) of object;
property OnMeasureItem: TMenuMeasureItemEvent;
該事件在菜單條監(jiān)測(cè)自身的尺寸時(shí)產(chǎn)生，其中參數(shù)Acanvas定義繪制的繪圖對(duì)象，參數(shù)Width、Height制定菜單項(xiàng)的默認(rèn)尺寸，注意到這兩個(gè)定義前的var了嗎，說(shuō)明你可以在OnMeasureItem事件處理函數(shù)中改變這兩個(gè)值，也就是改變菜單的大小。
OnDrawItem事件的定義如下：
type TMenuDrawItemEvent = procedure (Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean) of object;
property OnDrawItem: TMenuDrawItemEvent;
該事件在菜單繪制時(shí)引發(fā)，其中參數(shù)Acanvas定義菜單繪制對(duì)象，參數(shù)Arect制定菜單的繪制區(qū)域，參數(shù)Selected定義當(dāng)前菜單項(xiàng)是否被選中。
從上面的介紹可以看到，要實(shí)現(xiàn)自定義的菜單，只要在OnMeasureItem事件中編寫代碼改變菜單項(xiàng)的尺寸，然后在OnDrawItem事件中繪制自己需要的效果就可以了。
下面我痛過具體的范例來(lái)做說(shuō)明，這個(gè)范例是使自己的菜單實(shí)現(xiàn)象Windows開始菜單一樣的顯示Banner條的功能。同時(shí)這個(gè)程序還能實(shí)現(xiàn)對(duì)被選中的菜單條進(jìn)行漸變色填充（就象3721中文網(wǎng)址軟件的任務(wù)欄菜單那樣）。程序的思路是這樣的，首先建立一個(gè)長(zhǎng)條型的位圖，然后在每一個(gè)菜單條的OnMeasureItem事件中根據(jù)要顯示在菜單上的文本和圖像以及程序的需要改變菜單項(xiàng)的寬度和高度，然后在OnDrawItem事件中將位圖中的相應(yīng)部分拷貝到菜單項(xiàng)上。如果該菜單條被選中，首先要改變Acanvas參數(shù)的畫刷顏色，然后再依次填充菜單條上的相應(yīng)部分，這樣就實(shí)現(xiàn)了對(duì)選中的菜單條實(shí)現(xiàn)漸變色填充。最后將文本輸出到菜單條上。
下面來(lái)介紹具體的程序，首先利用圖像軟件建立一個(gè)長(zhǎng)條型的位圖文件（你可以根據(jù)你的需要設(shè)定圖像的高寬比，在我的圖像中是10:1）。在Delphi中建立一個(gè)新的工程，在Form1中加入一個(gè)TImage控件，將控件的AutoSize屬性設(shè)置為True。然后在Form1中加入一個(gè)TMainMenu控件，將它的OwnerDraw屬性設(shè)置為True（這一點(diǎn)很重要，否則程序無(wú)法實(shí)現(xiàn)）在該TMainMenu下加入6個(gè)TMenuItem對(duì)象（鼠標(biāo)右健點(diǎn)擊TMainMenu控件，然后點(diǎn)擊彈出菜單的Menu Designer 項(xiàng)，就可以在設(shè)計(jì)窗口中添加菜單條了），將它們的Name屬性分別設(shè)置為 Caption1、Caption2、…、Caption6。
下面是具體的程序清單：
unit OwnerMenu;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
Menus, ExtCtrls, StdCtrls, ImgList;
type
TForm1 = class(TForm)
MainMenu1: TMainMenu;
Main1: TMenuItem;
Caption1: TMenuItem;
Caption2: TMenuItem;
Caption3: TMenuItem;
Caption4: TMenuItem;
Caption5: TMenuItem;
Caption6: TMenuItem;
Image1: TImage;
procedure Caption1MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
procedure Caption2MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
procedure Caption3MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
procedure Caption4MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
procedure Caption5MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
procedure Caption6MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
procedure Caption1DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
procedure Caption2DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
procedure Caption3DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
procedure Caption4DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
procedure Caption5DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
procedure Caption6DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
private
{ Private declarations }
public
procedure DrawItem(Sender: TMenuItem; ACanvas: TCanvas;ARect: TRect;
Selected: Boolean;strOUt:String);
{ Public declarations }
end;
var
Form1: TForm1;
i,iH,Ind,iW,iRate:Integer;
rTemp:TRect;
iG1,iG2:Integer;
implementation
{$R *.DFM}
procedure TForm1.DrawItem(Sender: TMenuItem; ACanvas: TCanvas;ARect: TRect;
Selected: Boolean;strOut:String);
var
j:Integer;
begin
i:=ARect.Bottom -ARect.Top; //獲得貼圖的高度和寬度
Ind:=Sender.MenuIndex;
iH:=Round(Image1.Height/6*Ind); //獲得貼圖位置
//將Image上相應(yīng)位置的位圖復(fù)制到菜單上
StretchBlt(ACanvas.Handle,ARect.Left,ARect.Top,iW,i,Image1.Canvas.Handle,0,iH,
Image1.Width,Round(Image1.Height/6),SRCCOPY);
if Selected then begin //該菜單項(xiàng)被選中
ACanvas.Font.Color := clWhite;
rTemp:=ARect;
rTemp.Left := rTemp.left+iW;
iG1:=Round((rTemp.Right - rTemp.Left)/10);
rTemp.Right := rTemp.Left +iG1;
for j:= 0 to 9 do begin //通過循環(huán)設(shè)置色彩漸變效果
ACanvas.Brush.Color := RGB(0,0,j*25);
ACanvas.FillRect(rTemp);
rTemp.Left := rTemp.Left +iG1;
rTemp.Right := rTemp.Left +iG1;
end;
end
else begin //該菜單項(xiàng)沒有被選中
ACanvas.Brush.Color := cl3DLight; //設(shè)置背景色為淺灰
rTemp:=ARect;
rTemp.Left := rTemp.left+iW;
ACanvas.FillRect(rTemp);
ACanvas.Font.Color := clBlack;
end;
//設(shè)置Canvas的畫筆填充模式為透明
ACanvas.Brush.Style:=bsClear;
//在菜單上輸出文字
ACanvas.TextOut(ARect.Left+iW+5,ARect.Top,strOut);
end;
procedure TForm1.Caption1MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
begin
//在OnMeasureItem事件中改變菜單的寬度和高度，下面5個(gè)程序同
//改變菜單的寬度和高度以容納文本
Height:=ACanvas.TextHeight('Caption1')+5;
Width:=ACanvas.TextWidth('Caption1')+5;
iRate:=Round(Image1.Height/(Height*6));
iW:=Round(Image1.Width /iRate);
Width:=Width+iW; //根據(jù)計(jì)算改變菜單寬度以容納附加的文本
end;
procedure TForm1.Caption2MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
begin
Height:=ACanvas.TextHeight('Caption1')+5;
Width:=ACanvas.TextWidth('Caption1')+5;
iRate:=Round(Image1.Height/(Height*6));
iW:=Round(Image1.Width /iRate);
Width:=Width+iW;
end;
procedure TForm1.Caption3MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
begin
Height:=ACanvas.TextHeight('Caption1')+5;
Width:=ACanvas.TextWidth('Caption1')+5;
iRate:=Round(Image1.Height/(Height*6));
iW:=Round(Image1.Width /iRate);
Width:=Width+iW;
end;
procedure TForm1.Caption4MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
begin
Height:=ACanvas.TextHeight('Caption1')+5;
Width:=ACanvas.TextWidth('Caption1')+5;
iRate:=Round(Image1.Height/(Height*6));
iW:=Round(Image1.Width /iRate);
Width:=Width+iW;
end;
procedure TForm1.Caption5MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
begin
Height:=ACanvas.TextHeight('Caption1')+5;
Width:=ACanvas.TextWidth('Caption1')+5;
iRate:=Round(Image1.Height/(Height*6));
iW:=Round(Image1.Width /iRate);
Width:=Width+iW;
end;
procedure TForm1.Caption6MeasureItem(Sender: TObject; ACanvas: TCanvas;
var Width, Height: Integer);
begin
Height:=ACanvas.TextHeight('Caption1')+5;
Width:=ACanvas.TextWidth('Caption1')+5;
iRate:=Round(Image1.Height/(Height*6));
iW:=Round(Image1.Width /iRate);
Width:=Width+iW;
end;
procedure TForm1.Caption1DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
begin
DrawItem(TMenuItem(Sender),ACanvas,ARect,Selected,'Caption1');
end;
procedure TForm1.Caption2DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
begin
DrawItem(TMenuItem(Sender),ACanvas,ARect,Selected,'Caption2');
end;
procedure TForm1.Caption3DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
begin
DrawItem(TMenuItem(Sender),ACanvas,ARect,Selected,'Caption3');
end;
procedure TForm1.Caption4DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
begin
DrawItem(TMenuItem(Sender),ACanvas,ARect,Selected,'Caption4');
end;
procedure TForm1.Caption5DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
begin
DrawItem(TMenuItem(Sender),ACanvas,ARect,Selected,'Caption5');
end;
procedure TForm1.Caption6DrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; Selected: Boolean);
begin
DrawItem(TMenuItem(Sender),ACanvas,ARect,Selected,'Caption6');
end;
end.
