C# unsafe 快速复制数组

     /// <summary>/// 复制内存/// </summary>/// <param name="dest">目标指针位置</param>/// <param name="src">源指针位置</param>/// <param name="count">字节长度</param>/// <returns></returns>[DllImport("msvcrt.dll")]public static extern IntPtr memcpy(IntPtr dest, IntPtr src, int count);unsafe static int[] MyCopy(int[] oriInts){int[] result = new int[oriInts.Length];int lenth= oriInts.Length;fixed (int* pOri= oriInts) //fixed语句获取指向任意值类型、任意值类型数组或字符串的指针{fixed (int* pResult = result){memcpy(new IntPtr(pResult), new IntPtr(pOri), sizeof(int) * lenth);//注意，第一个参数和第二个参数的顺序}}return result;}static int[] MyCopyB(int[] oriInts){int[] result = new int[oriInts.Length];for(int i=0;i<oriInts.Length;i++){result[i]= oriInts[i];}return result;}static void Main(string[] args){var a = sizeof(int);int[] ori = new int[100000000];for(int i = 0; i < ori.Length; i++){ori[i] = i;}Stopwatch sw = new Stopwatch();sw.Start();int[] copyA= MyCopy(ori);sw.Stop();Console.WriteLine(sw.ElapsedMilliseconds);sw.Restart();int[] copyB = MyCopyB(ori);sw.Stop();Console.WriteLine(sw.ElapsedMilliseconds);
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