（1） 假设你的COMMONDIALOG 控件叫CMDiag 用如下代码可以使你选择的打印机成为默认打印机"Printer" On Error Resume Next CMDiag.PrinterDefault = True CMDiag.CancelError = True CMDiag.ShowPrinter If Err.Number <> 0 Then Exit Sub （2） VB 里面， 原本改变预设打印机的方法是：(假设安装有两种打印机(驱动程式)) Set Printer = Printers(0) ' 将预设打印机设定成第一种打印机 Set Printer = Printers(1) ' 将预设打印机设定成第二种打印机 但实际上以上叙述有时候不会成功(原因不详)， 为了能够成功地改变预设打印机， 以下是呼叫Windows API 的方法：( 此一解决方案适用於 Windows 95,98) 1. API 的宣告： Const HWND_BROADCAST = &HFFFF& Const WM_WININICHANGE = &H1A Private Declare Function GetProfileString Lib "kernel32" Alias _ "GetProfileStringA" (ByVal lpAppName As String, ByVal lpKeyName As _ String, ByVal lpDefault As String, ByVal lpReturnedString As String, _ ByVal nSize As Long) As Long Private Declare Function WriteProfileString Lib "kernel32" Alias _ "WriteProfileStringA" (ByVal lpszSection As String, ByVal lpszKeyName _ As String, ByVal lpszString As String) As Long Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _ (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _ lParam As Any) As Long 2. 程式范例： PrinterName = "您想设定的打印机名称" Dim S As String, length As Long, hKey As Long S = String(80, Chr(0)) length = GetProfileString("devices", PrinterName, "", S, Len(S)) S = Left(S, length) Call WriteProfileString("windows", "device", PrinterName & "," & S) Call SendMessage(HWND_BROADCAST, WM_WININICHANGE, &H7FFF&, ByVal "windows") 至於改变 NT 预设打印机的方法， 则是改变登录资料库(Registry)打印机的设定， 在登录资料库中纪录 预设打印机的 Value 是: HKEY_CURRENT_USER \Software\Microsoft\WindowsNT\CurrentVersion\Windows subkey 的 Device value （3）VB中获取指定打印机的...
