[DllImport("kernel32.dll")]
        public static extern bool SetProcessWorkingSetSize(IntPtr process, int minSize, int maxSize);

public static void GarbageCollect()
        {
            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();
        }

        public static void FlushMemory()
        {
            GarbageCollect();

            if (Environment.OSVersion.Platform == PlatformID.Win32NT)
            {
                Win32.SetProcessWorkingSetSize(System.Diagnostics.Process.GetCurrentProcess().Handle, -1, -1);
            }
        }



NET里面还有一个类可以达到这个效果
   System.Diagnostics.Process.GetCurrentProcess().MinWorkingSet = new System.IntPtr(5);

采用定时释放+窗体打开的时候,效果很好,估计程序占的内存会在20,以下