為什麼要折磨人呢?因為正被 programing 折磨吧?
再看看它的代碼,有 bug 的!
/**
* 初始化双缓冲区
*/
void CTestDoubleBufferAppView::InitDoubleBufferL()
{
iBufBmp = new(ELeave)CWsBitmap(CEikonEnv::Static()->WsSession());
CleanupStack::PushL(iBufBmp);
User::LeaveIfError(iBufBmp->Create(Rect().Size(), CEikonEnv::Static()->ScreenDevice()->DisplayMode()));
iBufDevice = CFbsBitmapDevice::NewL(iBufBmp);
CleanupStack::PushL(iBufDevice);
User::LeaveIfError(iBufDevice->CreateBitmapContext(iBufGc));
CleanupStack::Pop(2); // iDevice, iBufBmp
}
/**
* 测试在缓冲区上绘制
*/
void CTestDoubleBufferAppView::DoTestDraw()
{
iBufGc->Clear(Rect());
// 在buffer里画方块,而不是在屏幕上
for (int i=0; i<100;
i+=2){
DrawRect(TRect(TPoint(i, i), TSize(50, 50)));}
}
/**
* View的重绘事件
*/
void CTestDoubleBufferAppView::Draw(const TRect& /*aRect*/) const
{
// 以下代码忽略
// // Get the standard graphics context
// CWindowGc& gc = SystemGc();
//
// // Gets the control's extent
// TRect drawRect(Rect());
//
// // Clears the screen
// gc.Clear(drawRect);
SystemGc().BitBlt(TPoint(0, 0), iBufBmp);
}
No comments:
Post a Comment