*API函数声明： Declare Function ReleaseCapture Lib "user32" () As Long Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long Public Const HTCAPTION = 2 Public Const WM_NCLBUTTONDOWN = &HA1 在 Form_MouseDown 事件中： Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single) ReleaseCapture SendMessage hwnd, WM_NCLBUTTONDOWN, HTCAPTION,0& End Sub
17、VB中如何使用延时函数？
*API函数声明： Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long) 调用： 注释：延时1秒 Call Sleep(1000)
18、调用修改屏幕保护口令的窗口：
Private Declare Function PwdChangePassword Lib "mpr" Alias "PwdChangePasswordA" (ByVal lpcRegkeyname As String, ByVal hwnd As Long, ByVal uiReserved1 As Long, ByVal uiReserved2 As Long) As Long 调用： Call PwdChangePassword("SCRSAVE", Me.hwnd, 0, 0)
19、使Windows开始屏幕保护： *API函数声明 Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long Const WM_SYSCOMMAND = &H112& Const SC_SCREENSAVE = &HF140& 注释：调用 Dim result As Long result = SendMessage(Form1.hWnd, WM_SYSCOMMAND, SC_SCREENSAVE, 0&)
20、如何改变Windows桌面背景？ *API函数声明 Const SPI_SETDESKWALLPAPER = 20 Const SPIF_UPDATEINIFILE = &H1 Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long 注释：调用 Call SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, "C:windowsClouds.bmp", SPIF_UPDATEINIFILE)
21、怎样确定系统是否安装了声卡？
*API函数声明： Declare Function waveOutGetNumDevs Lib "winmm.dll" Alias "waveOutGetNumDevs" () As Long 代码如下： Dim i As Integer i = waveOutGetNumDevs() If i > 0 Then MsgBox "你的系统可以播放声音。", vbInformation, "声卡检测" Else MsgBox "你的系统不能播放声音。", vbInformation, "声卡检测" End If
22、如何找到CD-ROM驱动器的盘号？ 下面的函数将检查你计算机所有的驱动器看是否是 CD-ROM，如果是就返回驱动器号，如果没有就返回空字符 Public Function GetCDROMDrive() As String Dim lType As Long,i As Integer,tmpDrive as String,found as Boolean On Error GoTo errL For i = 0 To 25 tmpDrive = Chr(65 + i) & ":" lType = GetDriveType(tmpDrive) 注释：Win32 API 函数 If (lType = DRIVE_CDROM) Then 注释：Win32 API 常数 found = True Exit For End If Next If Not found Then tmpDrive = "" BI_GetCDROMDrive = tmpDrive exit Function errL: msgbox error$ End Function
23、如何将文件放入回收站？
**API函数声明 Public Type SHFILEOPSTRUCT hwnd As Long wFunc As Long pFrom As String pTo As String fFlags As Integer fAnyOperationsAborted As Long hNameMappings As Long lpszProgressTitle As Long End Type Public Declare Function SHFileOperation Lib _ "shell32.dll" Alias "SHFileOperationA" (lpFileOp As SHFILEOPSTRUCT) As Long Public Const FO_DELETE = &H3 Public Const FOF_ALLOWUNDO = &H40 注释：调用 Dim SHop As SHFILEOPSTRUCT, strFile as string With SHop .wFunc = FO_DELETE .pFrom = strFile + Chr(0) .fFlags = FOF_ALLOWUNDO End With
24、VB中如何使用未安装的字体？ Declare Function AddFontResource Lib "gdi32" Alias "AddFontResourceA" (ByVal lpFileName As String) As Long Declare Function RemoveFontResource Lib "gdi32" Alias "RemoveFontResourceA" (ByVal lpFileName As String) As Long 增加字体： Dim lResult As Long lResult = AddFontResource("c:myAppmyFont.ttf") 删除字体： Dim lResult As Long lResult = RemoveFontResource("c:myAppmyFont.ttf")
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