如何扩展VCL的hint

默认的Hint窗口展现如下：

这种情况下可以操作有窗口的背景颜色，字体样式

Application.Color

 

有的时候仅仅是文字满足不了我们的需求，比例如下格式：

这个时候就应该执行以下步骤：

1.新建一个单元，基层自：THintWindow;

2.重写THintWindow的PCPaint方法或者Paint方法来绘制自己想要的格式;

3.将全局变量HintWindowClass赋值为你所写的类（这步必须要在Application创建form之前）;

请参见如下代码：

自定义类

unit MyHintWindow;



interface

  uses

    Forms,Windows,Messages,Controls,Themes,Classes,Graphics;



type

  TMyHintWindow = class(THintWindow)

  protected

    procedure NCPaint(DC: HDC); override;

    procedure Paint; override;

  end;



  TMyHintWindowClass = class of TMyHintWindow;



implementation

var

  tempBmp:TBitMap;

  procedure init;

  begin

    tempBmp := TBitmap.Create;

    tempBmp.LoadFromFile('Chrysanthemum.bmp');

  end;

  { TMyHintWindow }





procedure TMyHintWindow.NCPaint(DC: HDC);

begin

  inherited;

  //在这里写入绘画非客户区的代码

end; 



procedure TMyHintWindow.Paint;

var

  clientRect:TRect;

begin

  Self.Width := 500;

  Self.Height := 500;

  clientRect:= GetClientRect;

  clientRect.Bottom := clientRect.Top + 3;

  Canvas.Brush.Color := clred;

  Canvas.FillRect(clientRect);

  Canvas.Brush.Color := clWhite;

  clientRect:= GetClientRect;

  clientRect.Top := clientRect.Top + 3;

  Canvas.FillRect(clientRect);

  Canvas.TextOut(100,3,Caption);

  Canvas.Draw(0,18,tempBmp);

end;



initialization

  init;

finalization

  tempBmp.Free;

end.

工程单元代码如下：

program Project1;



uses

  Forms,

  Unit1 in 'Unit1.pas' {Form1},

  MyHintWindow in 'MyHintWindow.pas';



{$R *.res}



begin

  Application.HintColor := $000000;

  Application.HintHidePause := 10000;

  HintWindowClass := TMyHintWindow;

  Application.Initialize;

  Application.CreateForm(TForm1, Form1);

  Application.Run;

end.