VB中的getopenfilename函数(API)怎么用地？谢了

Question

最好举个例子，说得通欲易懂些，
谢了
不要到网上找一大堆的资料来充噢！

Answer 1

下面是GetOpenFileName的例子：
Option Explicit

Private Declare Function GetOpenFileName Lib "comdlg32.dll" Alias _
"GetOpenFileNameA" (pOpenfilename As OPENFILENAME) As Long

Private Type OPENFILENAME
lStructSize As Long
hwndOwner As Long
hInstance As Long
lpstrFilter As String
lpstrCustomFilter As String
nMaxCustFilter As Long
nFilterIndex As Long
lpstrFile As String
nMaxFile As Long
lpstrFileTitle As String
nMaxFileTitle As Long
lpstrInitialDir As String
lpstrTitle As String
flags As Long
nFileOffset As Integer
nFileExtension As Integer
lpstrDefExt As String
lCustData As Long
lpfnHook As Long
lpTemplateName As String
End Type

Private Sub Command1_Click()
Dim OpenFile As OPENFILENAME
Dim lReturn As Long
Dim sFilter As String
OpenFile.lStructSize = Len(OpenFile)
OpenFile.hwndOwner = Form1.hWnd
OpenFile.hInstance = App.hInstance
sFilter = "Batch Files (*.bat)" & Chr(0) & "*.BAT" & Chr(0)
OpenFile.lpstrFilter = sFilter
OpenFile.nFilterIndex = 1
OpenFile.lpstrFile = String(257, 0)
OpenFile.nMaxFile = Len(OpenFile.lpstrFile) - 1
OpenFile.lpstrFileTitle = OpenFile.lpstrFile
OpenFile.nMaxFileTitle = OpenFile.nMaxFile
OpenFile.lpstrInitialDir = "C:\"
OpenFile.lpstrTitle = "Use the Comdlg API not the OCX"
OpenFile.flags = 0
lReturn = GetOpenFileName(OpenFile)
If lReturn = 0 Then
MsgBox "The User pressed the Cancel Button"
Else
MsgBox "The user Chose " & Trim(OpenFile.lpstrFile)
End If
End Sub

选择颜色的函数是ChooseColor，选择字体的函数是ChooseFont。几个函数的用法类似，都是调用一个结构，结构的定义在Win32api.txt中可以找到，详细的说明在Win API的帮助中有。