可扩展的对话框.pptx

2020 3 6 1 案例2 可扩展的对话框 2020 3 6 2 需求与目标 这个功能类似QQ的显示聊天记录当用户要显示一些过多的选择时 对话框自动扩展其大小 将隐藏的部分显示出来 2020 3 6 3 效果 2020 3 6 4 效果 2020 3 6 5 手段 利用CDialog类的SetRect函数来设定对话框的大小 2020 3 6 6 手段 利用CDialog类的SetRect函数来设定对话框的大小调用MoveWindow函数来实现改变对话框的大小 2020 3 6 7 编程步骤 1 使用AppWizard创建一个基于对话框的应用程序 2020 3 6 8 编程步骤 2 为对话框添加一些控件 2020 3 6 9 编程步骤 2 2020 3 6 10 编程步骤 2 2020 3 6 11 编程步骤 3 为对话框添加3个成员变量 BOOLm bExpand 记录是否已经扩展对话框UINTm nExpandedHeight 扩展后对话框的高度UINTm nNormalHeight 扩展前对话框的高度 2020 3 6 12 BOOL typedefintBOOL typedeflongBOOL ABooleanvalue 2020 3 6 13 UINT typedefunsignedintUINT A16 bitunsignedintegeronWindowsversions3 0and3 1 a32 bitunsignedintegeronWin32 2020 3 6 14 编程步骤 4 在对话框的OnInitDialog函数中加入以下代码 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 2020 3 6 15 CWnd GetWindowRect voidGetWindowRect LPRECTlpRect const lpRectPointstoaCRectobjectoraRECTstructurethatwillreceivethescreencoordinatesoftheupper leftandlower rightcorners RemarksCopiesthedimensionsoftheboundingrectangleoftheCWndobjecttothestructurepointedtobylpRect Thedimensionsaregiveninscreencoordinatesrelativetotheupper leftcornerofthedisplayscreen Thedimensionsofthecaption border andscrollbars ifpresent areincluded 2020 3 6 16 RECT LPRECT typedefstructtagRECT LONGleft LONGtop LONGright LONGbottom RECT PRECT NEAR NPRECT FAR LPRECT 2020 3 6 17 CRect classCRect publictagRECT public retrievesthewidthintWidth const returnstheheightintHeight const 2020 3 6 18 CWnd GetDlgItem CWnd GetDlgItem intnID const nIDSpecifiestheidentifierofthecontrolorchildwindowtoberetrieved ReturnValueApointertothegivencontrolorchildwindow IfnocontrolwiththeintegerIDgivenbythenIDparameterexists thevalueisNULL Thereturnedpointermaybetemporaryandshouldnotbestoredforlateruse RemarksRetrievesapointertothespecifiedcontrolorchildwindowinadialogboxorotherwindow ThepointerreturnedisusuallycasttothetypeofcontrolidentifiedbynID 2020 3 6 19 控件ID resource h defineIDC BORDER1000 defineIDC EXPAND1001 2020 3 6 20 CRect SetRect voidSetRect intx1 inty1 intx2 inty2 x1Specifiesthex coordinateoftheupper leftcorner y1Specifiesthey coordinateoftheupper leftcorner x2Specifiesthex coordinateofthelower rightcorner y2Specifiesthey coordinateofthelower rightcorner RemarksSetsthedimensionsofCRecttothespecifiedcoordinates 2020 3 6 21 CWnd MoveWindow voidMoveWindow LPCRECTlpRect BOOLbRepaint TRUE lpRectTheCRectobjectorRECTstructurethatspecifiesthenewsizeandposition bRepaintSpecifieswhetherCWndistoberepainted RemarksChangesthepositionanddimensions Foratop levelCWndobject thexandyparametersarerelativetotheupper leftcornerofthescreen ForachildCWndobject theyarerelativetotheupper leftcorneroftheparentwindow sclientarea 2020 3 6 22 编程步骤 5 为 隐藏 按钮添加单击响应函数OnExpand 2020 3 6 23 编程步骤 5 为 隐藏 按钮添加单击响应函数OnExpand voidCExpandDlgDlg OnExpand m bExpand m bExpand CRectrcDlg GetWindowRect rcDlg 2020 3 6 24 编程步骤 5 if m bExpand rcDlg SetRect rcDlg left rcDlg top rcDlg left rcDlg Width rcDlg top m nExpandedHeight m expand SetWindowText 隐藏 else rcDlg SetRect rcDlg left rcDlg top rcDlg left rcDlg Width rcDlg top m nNormalHeight m expand SetWindowText 显示 MoveWindow rcDlg TRUE 2020 3 6 25 CWnd SetWindowText voidSetWindowText LPCTSTRlpszString lpszStringPointstoaCStringobjectornull terminatedstringtobeusedasthenewtitleorcontroltext Remarks