Question

C++谁能解释下每句的意思

第四题
CWnd*pWnd=GetDlgItem(IDC_DRAW);
pWnd->UpdateWindow();
CDC* pDC=pWnd->GetDC();
CBrush drawBrush;
drawBrush.CreateHatchBrush(m_nDrawPattern,RGB(170,
170,170));
CBrush*pOldBrush=pDC->SelectObject(&drawBrush);
CRect rcClient;
pWnd->GetClientRect(rcClient);
pDC->Rectangle(rcClient);
pDC->SelectObject(pOldBrush);

第六题
pDC->SetMapMode(MM_ISOTROPIC);//ANISOTROPIC,TEXT
pDC->SetWindowExt(1000,1000);
CRect rClient;
GetClientRect(&rClient);
pDC->SetViewportExt(rClient.right,rClient.bottom);
pDC->SetViewportOrg(rClient.right/2,rClient.bottom/2);
pDC->Ellipse(-500,-500,500,500);

LOGFONT lf;
memset(&lf,0,sizeof(LOGFONT));
lf.lfHeight=120;
lf.lfCharSet=GB2312_CHARSET;
lf.lfWeight=FW_BOLD;
wcscpy(lf.lfFaceName,_T("宋体"));
CFont font,*Oldfont;
font.CreateFontIndirect(&lf);
Oldfont=(CFont*)pDC->SelectObject(&lf);
pDC->TextOutW(-20,0,_T("椭圆"));
pDC->SelectObject(Oldfont);
font.DeleteObject();
ReleaseDC(pDC);

第七题
CheckRadioButton(IDC_AGE_L18,IDC_AGE_M38,IDC_AGE_18TO27);
CheckRadioButton(IDC_CM_ADSL,IDC_CM_OTHER,IDC_CM_LAN);
CButton* pBtn=(CButton*)GetDlgItem(IDC_CHECK_POP);
pBtn->SetCheck(1);

Answer 1

CWnd*pWnd=GetDlgItem(IDC_DRAW);//获取ID为IDC_DRAW控件窗口指针

pWnd->UpdateWindow();//更新窗口显示 

CDC* pDC=pWnd->GetDC();//获取设备DC

CBrush drawBrush;//构建画刷

drawBrush.CreateHatchBrush(m_nDrawPattern,RGB(170,

170,170));//设置画刷信息

CBrush*pOldBrush=pDC->SelectObject(&drawBrush);//将画刷选入设备DC

CRect rcClient;

pWnd->GetClientRect(rcClient);//获取窗口客户区范围

pDC->Rectangle(rcClient);//绘制矩形

pDC->SelectObject(pOldBrush);//还原旧画刷


第六题

pDC->SetMapMode(MM_ISOTROPIC);//ANISOTROPIC,TEXT

pDC->SetWindowExt(1000,1000);//设置窗口大小

CRect rClient;

GetClientRect(&rClient);

pDC->SetViewportExt(rClient.right,rClient.bottom);//设置视口范围

pDC->SetViewportOrg(rClient.right/2,rClient.bottom/2);//设置视口原点坐标

pDC->Ellipse(-500,-500,500,500);//画椭圆

 

LOGFONT lf;

memset(&lf,0,sizeof(LOGFONT));

lf.lfHeight=120;

lf.lfCharSet=GB2312_CHARSET;

lf.lfWeight=FW_BOLD;

wcscpy(lf.lfFaceName,_T("宋体"));

CFont font,*Oldfont;

font.CreateFontIndirect(&lf);//根据逻辑字体设置创建字体

Oldfont=(CFont*)pDC->SelectObject(&lf);//选择字体入DC

pDC->TextOutW(-20,0,_T("椭圆"));//使用选择字体在-20,0坐标输出“椭圆”

pDC->SelectObject(Oldfont);

font.DeleteObject();

ReleaseDC(pDC);


第七题

CheckRadioButton(IDC_AGE_L18,IDC_AGE_M38,IDC_AGE_18TO27);//从Radio按钮序列中选中ID为IDC_AGE_18T027的单选按钮

CheckRadioButton(IDC_CM_ADSL,IDC_CM_OTHER,IDC_CM_LAN); 

CButton* pBtn=(CButton*)GetDlgItem(IDC_CHECK_POP);//获取复选按钮指针

pBtn->SetCheck(1);//设置复选按钮为选中状态

Answer 2

第四题
CWnd*pWnd=GetDlgItem(IDC_DRAW);
pWnd->UpdateWindow();
CDC* pDC=pWnd->GetDC();
CBrush drawBrush;
drawBrush.CreateHatchBrush(m_nDrawPattern,RGB(170,
170,170));
CBrush*pOldBrush=pDC->SelectObject(&drawBrush);
CRect rcClient;
pWnd->GetClientRect(rcClient);
pDC->Rectangle(rcClient);
pDC->SelectObject(pOldBrush);

首先获得控件的窗口，然后获得内存绘图设备句柄，创建一个刷子对象，选中创建的刷子并保存原来的刷子，用新刷子刷新控件客户窗口范围，再恢复旧刷子。

第六题
pDC->SetMapMode(MM_ISOTROPIC);//ANISOTROPIC,TEXT
pDC->SetWindowExt(1000,1000);
CRect rClient;
GetClientRect(&rClient);
pDC->SetViewportExt(rClient.right,rClient.bottom);
pDC->SetViewportOrg(rClient.right/2,rClient.bottom/2);
pDC->Ellipse(-500,-500,500,500);

LOGFONT lf;
memset(&lf,0,sizeof(LOGFONT));
lf.lfHeight=120;
lf.lfCharSet=GB2312_CHARSET;
lf.lfWeight=FW_BOLD;
wcscpy(lf.lfFaceName,_T("宋体"));
CFont font,*Oldfont;
font.CreateFontIndirect(&lf);
Oldfont=(CFont*)pDC->SelectObject(&lf);
pDC->TextOutW(-20,0,_T("椭圆"));
pDC->SelectObject(Oldfont);
font.DeleteObject();
ReleaseDC(pDC);

设置映射模式为等比例轴模式。设置窗口大小，获得客户区域范围，设置视窗范围，绘制一个椭圆。创建一个字体，宋体120大小，选中新字体并保存旧字体，在坐标（-20，0）位置输出汉字“椭圆”，恢复旧字体，删除创建的新字体，释放内存设备句柄。

第七题
CheckRadioButton(IDC_AGE_L18,IDC_AGE_M38,IDC_AGE_18TO27);
CheckRadioButton(IDC_CM_ADSL,IDC_CM_OTHER,IDC_CM_LAN);
CButton* pBtn=(CButton*)GetDlgItem(IDC_CHECK_POP);
pBtn->SetCheck(1);

创建2个单选按钮组。
选中IDC-CHECK-POP按钮。

Answer 3

这三题都是mfc相关的编程，第一题是设置某个控件的颜色；第二题是用自定义的字体在界面上指定位置显示“椭圆”文本；第三题是设置一个单选框为选中状态。

Answer 4

msdn.microsoft.com去查这些函数什么意思.