GCHandle.Alloc 메서드

Source:

GCHandle.cs

Source:

GCHandle.cs

Source:

GCHandle.cs

Source:

GCHandle.cs

Source:

GCHandle.cs

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);

public static System.Runtime.InteropServices.GCHandle Alloc(object value);

[<System.Security.SecurityCritical>]
static member Alloc : obj -> System.Runtime.InteropServices.GCHandle

static member Alloc : obj -> System.Runtime.InteropServices.GCHandle

Public Shared Function Alloc (value As Object) As GCHandle

매개 변수

반품

가비지 수집으로부터 개체를 보호하는 새 GCHandle 항목입니다. 더 GCHandle 이상 필요하지 않은 경우 릴리스 Free() 해야 합니다.

특성

SecurityCriticalAttribute

예제

다음 예제에서는 관리되는 개체가 수집되지 않도록 하는 메서드를 App 사용하여 관리되는 개체에 대한 핸들을 만드는 클래스를 보여 GCHandle.Alloc 줍니다. 메서드에 대한 EnumWindows 호출은 대리자와 관리되는 개체(둘 다 관리되는 형식으로 선언되었지만 표시되지 않음)를 전달하고 핸들을 IntPtr캐스팅합니다. 관리되지 않는 함수는 콜백 함수의 매개 변수로 형식을 호출자에게 다시 전달합니다.

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

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();
    }

    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 불투명하므로 핸들을 통해 포함하는 개체의 주소를 확인할 수 없습니다.

추가 정보

• GCHandleType

Source:

GCHandle.cs

Source:

GCHandle.cs

Source:

GCHandle.cs

Source:

GCHandle.cs

Source:

GCHandle.cs

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);

public static System.Runtime.InteropServices.GCHandle Alloc(object value, System.Runtime.InteropServices.GCHandleType type);

[<System.Security.SecurityCritical>]
static member Alloc : obj * System.Runtime.InteropServices.GCHandleType -> System.Runtime.InteropServices.GCHandle

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

반품

지정된 형식의 새 GCHandle 형식입니다. 더 GCHandle 이상 필요하지 않은 경우 릴리스 Free() 해야 합니다.

특성

SecurityCriticalAttribute

예외

추가 정보

• GCHandleType