parabolawin.cpp

来自「C++Builder程序员编程手记《配书光盘》」· C++ 代码 · 共 85 行

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "ParabolaWin.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
Tparabola *parabola;
//---------------------------------------------------------------------------
__fastcall Tparabola::Tparabola(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------

void Tparabola::SetParabolaWin(HWND Window)
{
  HRGN ParabolaWin;
  TRect RectWin;
  TPoint vertexes[500];
  int i,step;
  double WinHeight,WinWidth,a,b;

  if(!SetWindowRgn(Window,0,false))
    ShowMessage("窗口初始化失败！");
  if(!GetWindowRect(Window,&RectWin))
    ShowMessage("取窗口信息失败！");
  WinHeight=RectWin.Bottom-RectWin.Top;
  WinWidth=RectWin.Right-RectWin.Left;
  step=WinWidth/3;
  a=-(4*WinHeight)/(WinWidth*WinWidth);
  b=(4*WinHeight)/WinWidth;

  vertexes[0].x=0;
  vertexes[0].y=0;
  vertexes[1].x=0;
  vertexes[1].y=GetSystemMetrics(SM_CYCAPTION);
  for(i=2;i<=step-2;i++)
  {
     vertexes[i].x=i*3;
     vertexes[i].y=(double)a*(i*3)*(i*3)+b*(i*3);
  }
  vertexes[step-2].x=RectWin.Right-RectWin.Left;
  vertexes[step-2].y=vertexes[1].y;
  vertexes[step-1].x=vertexes[step-2].x;
  vertexes[step-1].y=vertexes[0].y;

  ParabolaWin=CreatePolygonRgn(vertexes,step,WINDING);
  if(ParabolaWin==0)
    ShowMessage("创建窗体过程失败");
  else
    if(!SetWindowRgn(Window,ParabolaWin,true))
      ShowMessage("设置窗口失败！");
}
void __fastcall Tparabola::FormShow(TObject *Sender)
{
  SetParabolaWin(Handle);        
}
//---------------------------------------------------------------------------


//---------------------------------------------------------------------------

void __fastcall Tparabola::FormClose(TObject *Sender, TCloseAction &Action)
{
  SetWindowRgn(Handle,0,false);
}
//---------------------------------------------------------------------------

void __fastcall Tparabola::FormClick(TObject *Sender)
{
  Close();
}
//---------------------------------------------------------------------------

void __fastcall Tparabola::FormResize(TObject *Sender)
{
  SetParabolaWin(Handle);
  Invalidate();
}
//---------------------------------------------------------------------------