使用Buffer.BlockCopy。它的全部目的是快速執(zhí)行（請(qǐng)參見(jiàn)Buffer）：
與System.Array類(lèi)中的類(lèi)似方法相比，此類(lèi)提供了更好的操作原始類(lèi)型的性能。
誠(chéng)然，我還沒(méi)有做過(guò)任何基準(zhǔn)測(cè)試，但這就是文檔。它也適用于多維數(shù)組。只需確保始終指定要復(fù)制的字節(jié)數(shù)，而不是指定多少個(gè)元素，并且確保您正在處理原始數(shù)組。
另外，我還沒(méi)有對(duì)此進(jìn)行測(cè)試，但是如果將委托綁定到并直接調(diào)用它，則可能會(huì)使系統(tǒng)的性能降低System.Buffer.memcpyimpl一點(diǎn)。簽名是：
internal static unsafe void memcpyimpl(byte* src, byte* dest, int len)
它確實(shí)需要指針，但是我相信它已針對(duì)可能的最高速度進(jìn)行了優(yōu)化，因此，即使您手頭有組裝，我也認(rèn)為沒(méi)有任何方法可以使速度更快。
更新：
由于要求（并滿足我的好奇心），我對(duì)此進(jìn)行了測(cè)試：
using System;
using System.Diagnostics;
using System.Reflection;
unsafe delegate void MemCpyImpl(byte* src, byte* dest, int len);
static class Temp
{
//There really should be a generic CreateDelegate<T>() method... -___-
static MemCpyImpl memcpyimpl = (MemCpyImpl)Delegate.CreateDelegate(
typeof(MemCpyImpl), typeof(Buffer).GetMethod("memcpyimpl",
BindingFlags.Static | BindingFlags.NonPublic));
const int COUNT = 32, SIZE = 32 << 20;
//Use different buffers to help avoid CPU cache effects
static byte[]
aSource = new byte[SIZE], aTarget = new byte[SIZE],
bSource = new byte[SIZE], bTarget = new byte[SIZE],
cSource = new byte[SIZE], cTarget = new byte[SIZE];
static unsafe void TestUnsafe()
{
Stopwatch sw = Stopwatch.StartNew();
fixed (byte* pSrc = aSource)
fixed (byte* pDest = aTarget)
for (int i = 0; i < COUNT; i++)
memcpyimpl(pSrc, pDest, SIZE);
sw.Stop();
Console.WriteLine("Buffer.memcpyimpl: {0:N0} ticks", sw.ElapsedTicks);
}
static void TestBlockCopy()
{
Stopwatch sw = Stopwatch.StartNew();
sw.Start();
for (int i = 0; i < COUNT; i++)
Buffer.BlockCopy(bSource, 0, bTarget, 0, SIZE);
sw.Stop();
Console.WriteLine("Buffer.BlockCopy: {0:N0} ticks",
sw.ElapsedTicks);
}
static void TestArrayCopy()
{
Stopwatch sw = Stopwatch.StartNew();
sw.Start();
for (int i = 0; i < COUNT; i++)
Array.Copy(cSource, 0, cTarget, 0, SIZE);
sw.Stop();
Console.WriteLine("Array.Copy: {0:N0} ticks", sw.ElapsedTicks);
}
static void Main(string[] args)
{
for (int i = 0; i < 10; i++)
{
TestArrayCopy();
TestBlockCopy();
TestUnsafe();
Console.WriteLine();
}
}
}
結(jié)果：
Buffer.BlockCopy: 469,151 ticks
Array.Copy: 469,972 ticks
Buffer.memcpyimpl: 496,541 ticks
Buffer.BlockCopy: 421,011 ticks
Array.Copy: 430,694 ticks
Buffer.memcpyimpl: 410,933 ticks
Buffer.BlockCopy: 425,112 ticks
Array.Copy: 420,839 ticks
Buffer.memcpyimpl: 411,520 ticks
Buffer.BlockCopy: 424,329 ticks
Array.Copy: 420,288 ticks
Buffer.memcpyimpl: 405,598 ticks
Buffer.BlockCopy: 422,410 ticks
Array.Copy: 427,826 ticks
Buffer.memcpyimpl: 414,394 ticks
現(xiàn)在更改順序：
Array.Copy: 419,750 ticks
Buffer.memcpyimpl: 408,919 ticks
Buffer.BlockCopy: 419,774 ticks
Array.Copy: 430,529 ticks
Buffer.memcpyimpl: 412,148 ticks
Buffer.BlockCopy: 424,900 ticks
Array.Copy: 424,706 ticks
Buffer.memcpyimpl: 427,861 ticks
Buffer.BlockCopy: 421,929 ticks
Array.Copy: 420,556 ticks
Buffer.memcpyimpl: 421,541 ticks
Buffer.BlockCopy: 436,430 ticks
Array.Copy: 435,297 ticks
Buffer.memcpyimpl: 432,505 ticks
Buffer.BlockCopy: 441,493 ticks
現(xiàn)在再次更改順序：
Buffer.memcpyimpl: 430,874 ticks
Buffer.BlockCopy: 429,730 ticks
Array.Copy: 432,746 ticks
Buffer.memcpyimpl: 415,943 ticks
Buffer.BlockCopy: 423,809 ticks
Array.Copy: 428,703 ticks
Buffer.memcpyimpl: 421,270 ticks
Buffer.BlockCopy: 428,262 ticks
Array.Copy: 434,940 ticks
Buffer.memcpyimpl: 423,506 ticks
Buffer.BlockCopy: 427,220 ticks
Array.Copy: 431,606 ticks
Buffer.memcpyimpl: 422,900 ticks
Buffer.BlockCopy: 439,280 ticks
Array.Copy: 432,649 ticks
或者換句話說(shuō)：他們很有競(jìng)爭(zhēng)力；一般而言，memcpyimpl速度最快，但不必?fù)?dān)心。
