分享程序员开发的那些事...
更新时间：2022-05-22 12:03:01
有时候为了制作透明的控件,特别是外边缘不规则的控件,可将控件背后的窗口图片复制到控件中,重绘.这样控件看起来就象透明的.
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
.h文件中声明变量CMemoryDC m_EmptyMemDC;//空白内存DC(另外封装的CDC的类)
CBitmap m_BmpBackground;void CLabel::CopyBackground(CDC * pDC)
{ CRect theRt;//获取控件大小(此处是自定义的控件,在控件内部执行)
GetWindowRect(&theRt);
CPoint pt(theRt.left, theRt.top);
::ScreenToClient(GetParent()->m_hWnd,&pt);
CClientDC clientDC(this->GetParent());
//创建兼容位图
m_BmpBackground.CreateCompatibleBitmap(&clientDC, m_rect.Width(), m_rect.Height());
HBITMAP hOldBitmap = (HBITMAP)m_EmptyMemDC.SelectObject(&m_BmpBackground);
::StretchBlt(m_EmptyMemDC, 0, 0, theRt.Width(), theRt.Height(), clientDC.m_hDC,
pt.x, pt.y, theRt.Width(), theRt.Height(), SRCCOPY);
pDC->BitBlt(0, 0, m_rect.Width(), m_rect.Height(), &m_EmptyMemDC, 0, 0, SRCCOPY);
m_EmptyMemDC.SelectObject(hOldBitmap);
m_BmpBackground.DeleteObject();
} |