案例2：可擴展的對話框2023/10/171案例2：可擴展的對話框需求與目標(biāo)這個功能類似QQ的顯示聊天記錄當(dāng)用戶要顯示一些過多的選擇時，對話框自動擴展其大小，將隱藏的部分顯示出來2023/10/172案例2：可擴展的對話框效果2023/10/173案例2：可擴展的對話框效果2023/10/174案例2：可擴展的對話框手段利用CDialog類的SetRect函數(shù)來設(shè)定對話框的大小2023/10/175案例2：可擴展的對話框手段利用CDialog類的SetRect函數(shù)來設(shè)定對話框的大小調(diào)用MoveWindow函數(shù)來實現(xiàn)改變對話框的大小2023/10/176案例2：可擴展的對話框編程步驟（1）使用AppWizard創(chuàng)建一個基于對話框的應(yīng)用程序2023/10/177案例2：可擴展的對話框編程步驟（2）為對話框添加一些控件2023/10/178案例2：可擴展的對話框編程步驟（2）2023/10/179案例2：可擴展的對話框編程步驟（2）2023/10/1710案例2：可擴展的對話框編程步驟（3）為對話框添加3個成員變量：BOOLm_bExpand;//記錄是否已經(jīng)擴展對話框UINTm_nExpandedHeight;//擴展后對話框的高度UINTm_nNormalHeight;//擴展前對話框的高度2023/10/1711案例2：可擴展的對話框BOOLtypedefintBOOL;typedeflongBOOL;ABooleanvalue.

2023/10/1712案例2：可擴展的對話框UINT

typedefunsignedintUINT;A16-bitunsignedintegeronWindowsversions3.0and3.1;a32-bitunsignedintegeronWin32.

2023/10/1713案例2：可擴展的對話框編程步驟（4）在對話框的OnInitDialog函數(shù)中加入以下代碼： m_bExpand=FALSE; CRectrcDlg,rcMarker; GetWindowRect(rcDlg); m_nExpandedHeight=rcDlg.Height(); GetDlgItem(IDC_BORDER)->GetWindowRect(rcMarker); m_nNormalHeight=(rcMarker.top-rcDlg.top); rcDlg.SetRect(rcDlg.left,rcDlg.top,rcDlg.left+rcDlg.Width(),rcDlg.top+m_nNormalHeight); MoveWindow(rcDlg,TRUE);2023/10/1714案例2：可擴展的對話框CWnd::GetWindowRectvoid

GetWindowRect(

LPRECT

lpRect

)

const;

lpRectPointstoaCRectobjectoraRECTstructurethatwillreceivethescreencoordinatesoftheupper-leftandlower-rightcorners.RemarksCopiesthedimensionsoftheboundingrectangleoftheCWndobjecttothestructurepointedtobylpRect.Thedimensionsaregiveninscreencoordinatesrelativetotheupper-leftcornerofthedisplayscreen.Thedimensionsofthecaption,border,andscrollbars,ifpresent,areincluded.2023/10/1715案例2：可擴展的對話框RECT、LPRECTtypedefstructtagRECT{LONGleft;LONGtop;LONGright;LONGbottom;}RECT,*PRECT,NEAR*NPRECT,FAR*LPRECT;2023/10/1716案例2：可擴展的對話框CRectclassCRect:publictagRECT{public:…… //retrievesthewidth intWidth()const; //returnstheheight intHeight()const;……}2023/10/1717案例2：可擴展的對話框CWnd::GetDlgItem

CWnd*

GetDlgItem(

int

nID

)

const;nIDSpecifiestheidentifierofthecontrolorchildwindowtoberetrieved.ReturnValueApointertothegivencontrolorchildwindow.IfnocontrolwiththeintegerIDgivenbythenIDparameterexists,thevalueisNULL.Thereturnedpointermaybetemporaryandshouldnotbestoredforlateruse.RemarksRetrievesapointertothespecifiedcontrolorchildwindowinadialogboxorotherwindow.ThepointerreturnedisusuallycasttothetypeofcontrolidentifiedbynID.2023/10/1718案例2：可擴展的對話框控件IDresource.h#defineIDC_BORDER1000#defineIDC_EXPAND10012023/10/1719案例2：可擴展的對話框CRect::SetRectvoid

SetRect(

int

x1,

int

y1,

int

x2,

int

y2

);x1Specifiesthex-coordinateoftheupper-leftcorner.y1Specifiesthey-coordinateoftheupper-leftcorner.x2Specifiesthex-coordinateofthelower-rightcorner.y2Specifiesthey-coordinateofthelower-rightcorner.RemarksSetsthedimensionsofCRecttothespecifiedcoordinates.2023/10/1720案例2：可擴展的對話框CWnd::MoveWindowvoid

MoveWindow(

LPCRECT

lpRect,BOOL

bRepaint=TRUE

);lpRectTheCRectobjectorRECTstructurethatspecifiesthenewsizeandposition.bRepaintSpecifieswhetherCWndistoberepainted.RemarksChangesthepositionanddimensions.Foratop-levelCWndobject,thexandyparametersarerelativetotheupper-leftcornerofthescreen.ForachildCWndobject,theyarerelativetotheupper-leftcorneroftheparentwindow’sclientarea.2023/10/1721案例2：可擴展的對話框編程步驟（5）為“隱藏”按鈕添加單擊響應(yīng)函數(shù)OnExpand：2023/10/1722案例2：可擴展的對話框編程步驟（5）為“隱藏”按鈕添加單擊響應(yīng)函數(shù)OnExpand：voidCExpandDlgDlg::OnExpand(){ m_bExpand=!m_bExpand;

CRectrcDlg; GetWindowRect(rcDlg);2023/10/1723案例2：可擴展的對話框編程步驟（5） if(m_bExpand) { rcDlg.SetRect(rcDlg.left,rcDlg.top,rcDlg.left+rcDlg.Width(),rcDlg.top+m_nExpandedHeight); m_expand.SetWindowText("隱藏"); } else { rcDlg.SetRect(rcDlg.left,rcDlg.top,rcDlg.left+rcDlg.Width(),rcDlg.top+m_nNormalHeight); m_expand.SetWindowText("顯示"); } MoveWindow(rcDlg,TRUE);}2023/10/1724案例2：可擴展的對話框CWnd::SetWindowTextvoid

SetWindowText(

LPCTSTR

lpszString

);lpszStringPointstoaCStringobjectornull-terminatedstringtobeusedasthenewtitleorcontroltext.RemarksSetsthewindow’stitletothespecifie