本文整理匯總了VB.NET中Microsoft.Win32.SafeHandles.SafeFileHandle類的典型用法代碼示例。如果您正苦於以下問題：VB.NET SafeFileHandle類的具體用法？VB.NET SafeFileHandle怎麽用？VB.NET SafeFileHandle使用的例子？那麽, 這裏精選的類代碼示例或許可以為您提供幫助。
在下文中一共展示了SafeFileHandle類的1個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的VB.NET代碼示例。
示例1: SafeHandlesExample
' 導入命名空間
Imports Microsoft.Win32.SafeHandles
Imports System.Runtime.InteropServices
Imports System.ComponentModel
Module SafeHandlesExample
Sub Main()
Try
Dim loader As New UnmanagedFileLoader("example.xml")
Catch e As Exception
Console.WriteLine(e)
End Try
Console.ReadLine()
End Sub
End Module
Class UnmanagedFileLoader
Public Const FILE_ATTRIBUTE_NORMAL As Short = &H80
Public Const INVALID_HANDLE_VALUE As Short = -1
Public Const GENERIC_READ As Long = &H80000000
Public Const GENERIC_WRITE As UInteger = &H40000000
Public Const CREATE_NEW As UInteger = 1
Public Const CREATE_ALWAYS As UInteger = 2
Public Const OPEN_EXISTING As UInteger = 3
' Use interop to call the CreateFile function.
' For more information about CreateFile,
' see the unmanaged MSDN reference library.
<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Private Shared Function CreateFile(ByVal lpFileName As String, ByVal dwDesiredAccess As System.UInt32, ByVal dwShareMode As System.UInt32, ByVal lpSecurityAttributes As IntPtr, ByVal dwCreationDisposition As System.UInt32, ByVal dwFlagsAndAttributes As System.UInt32, ByVal hTemplateFile As IntPtr) As Microsoft.Win32.SafeHandles.SafeFileHandle
End Function
Private handleValue As Microsoft.Win32.SafeHandles.SafeFileHandle = Nothing
Public Sub New(ByVal Path As String)
Load(Path)
End Sub
Public Sub Load(ByVal Path As String)
If Path Is Nothing OrElse Path.Length = 0 Then
Throw New ArgumentNullException("Path")
End If
' Try to open the file.
handleValue = CreateFile(Path, GENERIC_WRITE, 0, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero)
' If the handle is invalid,
' get the last Win32 error
' and throw a Win32Exception.
If handleValue.IsInvalid Then
Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error())
End If
End Sub
Public ReadOnly Property Handle() As Microsoft.Win32.SafeHandles.SafeFileHandle
Get
' If the handle is valid,
' return it.
If Not handleValue.IsInvalid Then
Return handleValue
Else
Return Nothing
End If
End Get
End Property
End Class