GCHandle.Alloc 메서드

정의

지정된 개체의 핸들을 할당합니다.Allocates a handle for the specified object.

오버로드

Alloc(Object)

지정된 개체의 Normal 핸들을 할당합니다.Allocates a Normal handle for the specified object.

Alloc(Object, GCHandleType)

지정된 개체에 특정 형식의 핸들을 할당합니다.Allocates a handle of the specified type for the specified object.

Alloc(Object)

지정된 개체의 Normal 핸들을 할당합니다.Allocates a Normal handle for the specified object.

public:
 static System::Runtime::InteropServices::GCHandle Alloc(System::Object ^ value);
[System.Security.SecurityCritical]
public static System.Runtime.InteropServices.GCHandle Alloc (object value);
public static System.Runtime.InteropServices.GCHandle Alloc (object value);
static member Alloc : obj -> System.Runtime.InteropServices.GCHandle
Public Shared Function Alloc (value As Object) As GCHandle

매개 변수

value
Object

GCHandle을 사용하는 개체입니다.The object that uses the GCHandle.

반환

GCHandle

개체를 가비지 수집하지 못하게 하는 새 GCHandle입니다.A new GCHandle that protects the object from garbage collection. GCHandle은 더 이상 필요하지 않을 때 Free()를 사용하여 해제해야 합니다.This GCHandle must be released with Free() when it is no longer needed.

특성

예제

다음 예제에서는 관리 되는 개체가 수집 되지 않도록 방지 하는 GCHandle.Alloc 메서드를 사용 하 여 관리 되는 개체에 대 한 핸들을 만드는 App 클래스를 보여 줍니다.The following example shows an App class that creates a handle to a managed object using the GCHandle.Alloc method, which prevents the managed object from being collected. EnumWindows 메서드를 호출 하면 대리자와 관리 되는 개체 (둘 다 관리 되는 형식으로 선언 되지만 표시 되지 않음)가 전달 되 고 핸들이 IntPtr으로 캐스팅 됩니다.A call to the EnumWindows method passes a delegate and a managed object (both declared as managed types, but not shown), and casts the handle to an IntPtr. 호출자에 게 형식 콜백 함수의 매개 변수로 전달 하는 관리 되지 않는 함수입니다.The unmanaged function passes the type back to the caller as a parameter of the callback function.

using System;
using System.IO;
using System.Threading;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Security.Permissions;

public delegate bool CallBack(int handle, IntPtr param);

internal static class NativeMethods
{
    // passing managed object as LPARAM
    // BOOL EnumWindows(WNDENUMPROC lpEnumFunc, LPARAM lParam);

    [DllImport("user32.dll")]
    internal static extern bool EnumWindows(CallBack cb, IntPtr param);
}

public class App
{
    public static void Main()
    {
        Run();
    }

    [SecurityPermission(SecurityAction.Demand, UnmanagedCode = true)]
    public static void Run()
    {
        TextWriter tw = Console.Out;
        GCHandle gch = GCHandle.Alloc(tw);

        CallBack cewp = new CallBack(CaptureEnumWindowsProc);

        // platform invoke will prevent delegate to be garbage collected
        // before call ends

        NativeMethods.EnumWindows(cewp, GCHandle.ToIntPtr(gch));
        gch.Free();
    }

    private static bool CaptureEnumWindowsProc(int handle, IntPtr param)
    {
        GCHandle gch = GCHandle.FromIntPtr(param);
        TextWriter tw = (TextWriter)gch.Target;
        tw.WriteLine(handle);
        return true;
    }
}
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

설명

Normal 핸들은 불투명 합니다. 즉, 핸들을 통해 포함 된 개체의 주소를 확인할 수 없습니다.Normal handles are opaque, which means that you cannot resolve the address of the object it contains through the handle.

추가 정보

Alloc(Object, GCHandleType)

지정된 개체에 특정 형식의 핸들을 할당합니다.Allocates a handle of the specified type for the specified object.

public:
 static System::Runtime::InteropServices::GCHandle Alloc(System::Object ^ value, System::Runtime::InteropServices::GCHandleType type);
[System.Security.SecurityCritical]
public static System.Runtime.InteropServices.GCHandle Alloc (object value, System.Runtime.InteropServices.GCHandleType type);
public static System.Runtime.InteropServices.GCHandle Alloc (object value, System.Runtime.InteropServices.GCHandleType type);
static member Alloc : obj * System.Runtime.InteropServices.GCHandleType -> System.Runtime.InteropServices.GCHandle
Public Shared Function Alloc (value As Object, type As GCHandleType) As GCHandle

매개 변수

value
Object

GCHandle을 사용하는 개체입니다.The object that uses the GCHandle.

type
GCHandleType

만들려는 GCHandleType의 형식을 나타내는 GCHandle 값 중 하나입니다.One of the GCHandleType values, indicating the type of GCHandle to create.

반환

GCHandle

지정한 형식의 새 GCHandle입니다.A new GCHandle of the specified type. GCHandle은 더 이상 필요하지 않을 때 Free()를 사용하여 해제해야 합니다.This GCHandle must be released with Free() when it is no longer needed.

특성

예외

기본 형식이 아닌 (blittable이 아닌) 멤버가 있는 인스턴스를 고정할 수 없습니다.An instance with nonprimitive (non-blittable) members cannot be pinned.

추가 정보

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