static void FreeHGlobal(IntPtr hglobal);
[System.Security.SecurityCritical]
public static void FreeHGlobal (IntPtr hglobal);
public static void FreeHGlobal (IntPtr hglobal);
[<System.Security.SecurityCritical>]
static member FreeHGlobal : nativeint -> unit
static member FreeHGlobal : nativeint -> unit
Public Shared Sub FreeHGlobal (hglobal As IntPtr)
下列範例示範呼叫
FreeHGlobal
方法。 此程式代碼範例是提供給
Marshal
類別之較大範例的一部分。
// Demonstrate how to call GlobalAlloc and
// GlobalFree using the Marshal class.
IntPtr hglobal = Marshal::AllocHGlobal(100);
Marshal::FreeHGlobal(hglobal);
// Demonstrate how to call GlobalAlloc and
// GlobalFree using the Marshal class.
IntPtr hglobal = Marshal.AllocHGlobal(100);
Marshal.FreeHGlobal(hglobal);
' Demonstrate how to call GlobalAlloc and
' GlobalFree using the Marshal class.
Dim hglobal As IntPtr = Marshal.AllocHGlobal(100)
Marshal.FreeHGlobal(hglobal)
下列範例示範如何將Managed String 類別的內容轉換為 Unmanaged 記憶體,然後在完成時處置 Unmanaged 記憶體。
using namespace System;
using namespace System::Runtime::InteropServices;
#include <iostream> // for printf
int main()
// Create a managed string.
String^ managedString = "Hello unmanaged world (from the managed world).";
// Marshal the managed string to unmanaged memory.
char* stringPointer = (char*) Marshal::StringToHGlobalAnsi(managedString ).ToPointer();
printf("stringPointer = %s\n", stringPointer);
// Always free the unmanaged string.
Marshal::FreeHGlobal(IntPtr(stringPointer));
return 0;
using System;
using System.Runtime.InteropServices;
using System.Threading;
class MainFunction
static void Main()
Console.WriteLine("\nStringToGlobalAnsi\n");
// Create a managed string.
String managedString = "I am a managed String";
Console.WriteLine("1) managedString = " + managedString);
// Marshal the managed string to unmanaged memory.
IntPtr stringPointer = (IntPtr)Marshal.StringToHGlobalAnsi(managedString);
Console.WriteLine("2) stringPointer = {0}", stringPointer);
// Get the string back from unmanaged memory.
String RetrievedString = Marshal.PtrToStringAnsi(stringPointer);
Console.WriteLine("3) Retrieved from unmanaged memory = " + RetrievedString);
// Always free the unmanaged string.
Marshal.FreeHGlobal(stringPointer);
// IntPtr handle value is still the same:
Console.WriteLine("4) stringPointer = " + stringPointer);
// However, the data may be cleared after the memory is freed, depending on whether the memory allocated to stringPointer
// has been reclaimed or not. Uncommenting the following line (Thread.Sleep(1000)) increases the likelihood of the memory being reclaimed.
// Thread.Sleep(1000);
String RetrievedString2 = Marshal.PtrToStringAnsi(stringPointer);
Console.WriteLine("5) RetrievedString2 = " + RetrievedString2);
這個原生記憶體配置器是舊版 API,在 Windows 平臺上由特定 Win32 API 呼叫時,應該獨佔使用。 以 .NET 6 或更新版本為目標時,請在所有平臺上使用 NativeMemory 類別來配置原生記憶體。 以 .NET 6 或更早版本為目標時,請在所有平臺上使用 AllocCoTaskMem 來配置原生記憶體。
您可以使用 FreeHGlobal,從 AllocHGlobal、ReAllocHGlobal或任何對等的 Unmanaged API 方法所配置的全域堆積中釋放任何記憶體。 如果 hglobal
參數 IntPtr.Zero 方法不會執行任何動作。
FreeHGlobal 會從 Kernel32.DLL 公開 LocalFree 函式,這會釋放所有位元組,讓您無法再使用 hglobal
所指向的記憶體。
除了 FreeHGlobal之外,Marshal 類別還提供另外兩個記憶體解除分配 API 方法:DestroyStructure 和 FreeCoTaskMem。