有 BitMap 之Menu

【 tulaoshi.com - 编程语言 】

　　在Window API中，有一些名词要先清楚，假设有一功能表如下：

　　档案　 编辑 选项　-- hMenu　　(功能表)

　　+-------+

　　|复制　 |--------- hSubMenu (子功能表)

　　|贴上　 |

　　|减下 ------------- MenuID　 (功能表项目)

　　|　　　 |

　　+-------+

　　如果，我们使用vb的功能表编辑器做出上面的Menu，那 hMenu的取得使用GetMenu() API，而hSubMenu 的取得是 GetSubMenu，而GetSubMenu()的第二个叁数指的是功能表的第几个子功能表，以上例来说，编辑子功能表是第1个子功能表(以0为基准)，所以编辑子功能表的取得应用以下的呼叫 ：

　　hMenu = GetMenu(Me.hwnd)

　　hSubMenu = GetSubMenu(hMenu, 1) '取得编辑子功能表的hSubMenu

　　而功能表项目则由以下的呼叫取得，第二叁数指的是该子功能表的第几个项目(以0开始)，故复制 功能表项目 = 0　减下 = 2

　　MenuId = GetMenuItemID(hSubMenu, 0) '取得复制 的hMenuId接着便是以ModifyMenu来更动MenuId成BitMap的方式Set Pic1 = LoadPicture("E:cli.bmp")ModifyMenu hSubMenu, 0, MF_BITMAP Or MF_BYPOSITION, MenuId, pic1.HandleModifyMenu 第二个叁数　表示更动hSubMenu所指的子功能表中第几个功能表项目

　　第三个叁数　MF_BITMAP 表示用BitMap的方式显示

　　MF_STRING 表示用字串方式显示

　　MF_BYPOSITION 表示第二个叁数的值代表是依位置来算

　　第四个叁数　MenuId

　　第五个叁数　显示图的hBitMap

　　另外，如何做到MenuItem的左方有一小Bitmap，右方仍是字串呢，使用以下的API

SetMenuItemBitmaps(　　hSubMenu as Long , 　 // handle of 子功能表　　uItem　　as Long , 　 // 更动第几个Menu Item　　fuFlags as Long, 　 // menu item flags　　hbmUnchecked as Long,　// handle of unchecked bitmap　　hbmChecked as Long 　 // handle of checked bitmap　 )Set Pic2 = LoadPicture("e:cli2.BitMap")Call SetMenuItemBitmaps(hSubMenu, 1, MF_BYPOSITION,pic2.Handle, Pic2.Handle)

　　这里有一个地方要特别注意，到底hbmUnchecked/hbmchecked 所指的BitMap图有多大呢，

　　如果pic2所放入的BitMap太大，那不会出现我们想要的图，那得自己想办法缩图；而使

　　用以下的API可以取得Menu Item左边Bitmap图的大小(By Pixels)

　　i = GetMenuCheckMarkDimensions

　　wd5 = i Mod 2 ^ 16　'宽

　　hi5 = i / 2 ^ 16　　'高

　　而我们Load进来的图之宽 Me.ScaleX(pic2.Width, vbHimetric, vbPixels)

　　高 Me.ScaleY(pic2.Height, vbHimetric, vbPixels)

　　於是呢，我写了一个GetBitMapHandle 来取得hbmUnchecked/hbmchecked所需的BitMap

　　Handle，而且该hBitMap所指的图，大小刚好是系统内定的大小，而不必在乎原始的图

　　有多大，当然了，一定要使用BitMap图，不可使用icon/gif等之类的图，这是什麽原

　　因呢，这是因为我使用StdPicture物件来开启图形档，如果图形档是BitMap图，那麽，

　　stdPicture物件的Handle属性便是hBitmap。

以下在.basOption ExplicitPublic Const MF_BYCOMMAND = &H0&Public Const MF_BYPOSITION = &H400&Public Const MF_BITMAP = &H4&Public Const MF_STRING = &H0&Declare Function GetMenu Lib "user32" (ByVal hwnd As Long) As LongDeclare Function GetSubMenu Lib "user32" (ByVal hMenu As Long,_　　 ByVal nPos As Long) As LongDeclare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As LongDeclare Function GetMenuItemID Lib "user32" (ByVal hMenu As Long, _　　 ByVal nPos As Long) As LongDeclare Function ModifyMenu Lib "user32" Alias "ModifyMenuA" (ByVal _　　 hMenu As Long, ByVal nPosition As Long, _　　 ByVal wFlags As Long, ByVal wIDNewItem As Long,_　　 ByVal lpString As Any) As LongDeclare Function SetMenuItemBitmaps Lib "user32" (ByVal hMenu As Long,_　　 ByVal nPosition As Long, _　　 ByVal wFlags As Long, ByVal hBitmapUnchecked As Long, _　　 ByVal hBitmapChecked As Long) As LongDeclare Function GetMenuCheckMarkDimensions Lib "user32" () As LongDeclare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long,_　　 ByVal nWidth As Long, _　　　　 ByVal nHeight As Long) As LongDeclare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As LongDeclare Function SelectObject Lib "gdi32" (ByVal hdc As Long,_　　 ByVal hObject As Long) As LongDeclare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As LongDeclare Function StretchBlt Lib "gdi32" (ByVal hdc As Long,_　　 ByVal x As Long, ByVal y As Long, _　　 ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long,_　　 ByVal xSrc As Long,ByVal ySrc As Long, ByVal nSrcWidth As Long,_　　 ByVal nSrcHeight As Long, ByVal dwRop As Long) As LongConst SRCCOPY = &HCC0020Public TheForm As FormPublic Function GetBitMapHandle(ByVal FileName As String)Dim dstWidth As Long, dstHeight As LongDim srcWidth As Long, srcHeight As LongDim x As Long, y As LongDim pic As New StdPictureDim hDc5 As Long, i As LongDim hBitmap As LongDim hDstDc As LongSet pic = LoadPicture(FileName) 读取图形档hDc5 = CreateCompatibleDC(0) 建立Memory DCi = SelectObject(hDc5, pic.Handle) 在该memoryDC上放上bitmap图i = GetMenuCheckMarkDimensions 取得SetMenuItemBitmaps 所需Bitmap大小dstWidth = i Mod 2 ^ 16dstHeight = i / 2 ^ 16建一个大小为dstWidh * dstHeight大小的BitmaphBitmap = CreateCompatibleBitmap(TheForm.hdc, dstWidth, dstHeight)hDstDc = CreateCompatibleDC(TheForm.hdc) 建memory dc设该memory dc的绘图区大小=该bitmap大小，且在该memory dc上的绘图便是在该bitmap图上画图SelectObject hDstDc, hBitmapsrcHeight = TheForm.ScaleY(pic.Height, vbHimetric, vbPixels)srcWidth = TheForm.ScaleX(pic.Width, vbHimetric, vbPixels)Call StretchBlt(hDstDc, 0, 0, dstWidth, dstHeight, hDc5, 0, 0, _　　srcWidth, srcHeight, SRCCOPY)GetBitMapHandle = hBitmapCall DeleteDC(hDc5)Call DeleteDC(hDstDc)End Function以下在FormOption ExplicitPrivate hMenu As LongPrivate hSubMenu As LongPrivate MenuId As LongPrivate pic1 As New StdPicturePrivate pic2 As New StdPictureDim hBitmap As LongPrivate Sub Form_Load()Set TheForm = MeSet pic1 = LoadPicture("e:cli.bmp")hMenu = GetMenu(Me.hwnd)hSubMenu = GetSubMenu(hMenu, 1)MenuId = GetMenuItemID(hSubMenu, 1)ModifyMenu hSubMenu, 0, MF_BITMAP Or MF_BYPOSITION, MenuId, pic1.HandlehBitmap = GetBitMapHandle("e:cli.bmp")Call SetMenuItemBitmaps(hSubMenu, 1, MF_BYPOSITION, hBitmap, hBitmap)End SubPrivate Sub Form_Unload(Cancel As Integer)DeleteObject hBitmapEnd Sub