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GC.Collect Method

Forces an immediate garbage collection of all generations.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public static void Collect()

Use this method to try to reclaim all memory that is inaccessible.

All objects, regardless of how long they have been in memory, are considered for collection; however, objects that are referenced in managed code are not collected. Use this method to force the system to try to reclaim the maximum amount of available memory.

The following example demonstrates how to use the Collect method to perform a collection on all generations of memory. The code generates a number of unused objects, and then calls the Collect method to clean them from memory.

using System;

namespace GCCollectExample
    class MyGCCollectClass
        private const int maxGarbage = 1000;

        static void Main()
            // Put some objects in memory.
            Console.WriteLine("Memory used before collection: {0}", GC.GetTotalMemory(false));

            // Collect all generations of memory.
            Console.WriteLine("Memory used after full collection: {0}", GC.GetTotalMemory(true));

        static void MakeSomeGarbage()
            Version vt;

            for(int i = 0; i < maxGarbage; i++)
                // Create objects and release them to fill up memory 
                // with unused objects.
                vt = new Version();

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0