设置默认选中一个单选按钮，OnInitDialog()函数中添加:

CheckRadioButton(IDC_RADIO1, IDC_RADIO2, IDC_RADIO2);

按钮事件处理

1 void CMFCApplication3Dlg::OnBnClickedChkBlue()
2 {
3 // 选中蓝色让对话框失效，触发清除背景
4 Invalidate();
5 }
6
7 void CMFCApplication3Dlg::OnBnClickedChkRed()
8 {
9 OnBnClickedChkBlue();
10 }
11
12 void CMFCApplication3Dlg::OnBnClickedChkGreen()
13 {
14 OnBnClickedChkBlue();
15 }
16
17 void CMFCApplication3Dlg::OnBnClickedRadio1()
18 {
19 OnBnClickedChkBlue();
20 }
21
22 //清除背景时画图
23 BOOL CMFCApplication3Dlg::OnEraseBkgnd(CDC* pDC)
24 {
25 // TODO: 在此添加消息处理程序代码和/或调用默认值
26 BOOL bRet = CDialogEx::OnEraseBkgnd(pDC);
27 int nRed, nGreen, nBlue;
28 nRed = m_chk_red.GetCheck() ? 255 : 0;
29 nGreen = m_chk_green.GetCheck() ? 255 : 0;
30 nBlue = m_chk_blue.GetCheck() ? 255 : 0;
31
32 COLORREF crFore = RGB(nRed, nGreen, nBlue);
33 CBrush brush;
34 brush.CreateSolidBrush(crFore);
35 CBrush *pOldBrush = pDC->SelectObject(&brush);
36
37 RECT rc = { 50,20,150,120 };
38 if (m_rd_rect.GetCheck()) {
39 pDC->Rectangle(&rc);
40 }
41 else {
42 pDC->Ellipse(&rc);
43 }
44 pDC->SelectObject(pOldBrush);
45
46 return bRet;
47 }