本文整理匯總了VB.NET中System.Runtime.InteropServices.GCHandle.Alloc方法的典型用法代碼示例。如果您正苦於以下問題：VB.NET GCHandle.Alloc方法的具體用法？VB.NET GCHandle.Alloc怎麽用？VB.NET GCHandle.Alloc使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類System.Runtime.InteropServices.GCHandle的用法示例。
在下文中一共展示了GCHandle.Alloc方法的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: App
' 導入命名空間
Imports System.IO
Imports System.Threading
Imports System.Windows.Forms
Imports System.Runtime.InteropServices
Imports System.Security.Permissions
Public Delegate Function CallBack(ByVal handle As Integer, ByVal param As IntPtr) As Boolean
Friend Module NativeMethods
' passing managed object as LPARAM
' BOOL EnumWindows(WNDENUMPROC lpEnumFunc, LPARAM lParam);
<DllImport("user32.dll")>
Friend Function EnumWindows(ByVal cb As CallBack, ByVal param As IntPtr) As Boolean
End Function
End Module
Module App
Sub Main()
Run()
End Sub
<SecurityPermission(SecurityAction.Demand, UnmanagedCode:=True)>
Sub Run()
Dim tw As TextWriter = Console.Out
Dim gch As GCHandle = GCHandle.Alloc(tw)
Dim cewp As CallBack
cewp = AddressOf CaptureEnumWindowsProc
' platform invoke will prevent delegate to be garbage collected
' before call ends
NativeMethods.EnumWindows(cewp, GCHandle.ToIntPtr(gch))
gch.Free()
End Sub
Function CaptureEnumWindowsProc(ByVal handle As Integer, ByVal param As IntPtr) As Boolean
Dim gch As GCHandle = GCHandle.FromIntPtr(param)
Dim tw As TextWriter = CType(gch.Target, TextWriter)
tw.WriteLine(handle)
Return True
End Function
End Module