项目-》属性-》生成-》允许不安全代码 点上 class TestCopy { // The unsafe keyword allows pointers to be used within the following method: static unsafe void Copy(byte[] src, int srcIndex, byte[] dst, int dstIndex, int count) { if (src == null || srcIndex < 0 || dst == null || dstIndex < 0 || count < 0) { throw new System.ArgumentException(); } int srcLen = src.Length; int dstLen = dst.Length; if (srcLen - srcIndex < count || dstLen - dstIndex < count) { throw new System.ArgumentException(); } // The following fixed statement pins the location of the src and dst objects // in memory so that they will not be moved by garbage collection. fixed (byte* pSrc = src, pDst = dst) { byte* ps = pSrc; byte* pd = pDst; // Loop over the count in blocks of 4 bytes, copying an integer (4 bytes) at a time: for (int i = 0 ; i < count / 4 ; i++) { *((int*)pd) = *((int*)ps); pd += 4; ps += 4; } // Complete the copy by moving any bytes that weren't moved in blocks of 4: for (int i = 0; i < count % 4 ; i++) { *pd = *ps; pd++; ps++; } } } static void Main() { byte[] a = new byte[100]; byte[] b = new byte[100]; for (int i = 0; i < 100; ++i) { a[i] = (byte)i; } Copy(a, 0, b, 0, 100); System.Console.WriteLine("The first 10 elements are:"); for (int i = 0; i < 10; ++i) { System.Console.Write(b[i] + " "); } System.Console.WriteLine("\n"); } }来自MSDN
class TestCopy
{
// The unsafe keyword allows pointers to be used within the following method:
static unsafe void Copy(byte[] src, int srcIndex, byte[] dst, int dstIndex, int count)
{
if (src == null || srcIndex < 0 ||
dst == null || dstIndex < 0 || count < 0)
{
throw new System.ArgumentException();
} int srcLen = src.Length;
int dstLen = dst.Length;
if (srcLen - srcIndex < count || dstLen - dstIndex < count)
{
throw new System.ArgumentException();
} // The following fixed statement pins the location of the src and dst objects
// in memory so that they will not be moved by garbage collection.
fixed (byte* pSrc = src, pDst = dst)
{
byte* ps = pSrc;
byte* pd = pDst; // Loop over the count in blocks of 4 bytes, copying an integer (4 bytes) at a time:
for (int i = 0 ; i < count / 4 ; i++)
{
*((int*)pd) = *((int*)ps);
pd += 4;
ps += 4;
} // Complete the copy by moving any bytes that weren't moved in blocks of 4:
for (int i = 0; i < count % 4 ; i++)
{
*pd = *ps;
pd++;
ps++;
}
}
} static void Main()
{
byte[] a = new byte[100];
byte[] b = new byte[100]; for (int i = 0; i < 100; ++i)
{
a[i] = (byte)i;
} Copy(a, 0, b, 0, 100);
System.Console.WriteLine("The first 10 elements are:"); for (int i = 0; i < 10; ++i)
{
System.Console.Write(b[i] + " ");
}
System.Console.WriteLine("\n");
}
}来自MSDN
为什么要用这么BT的定义呢....
先问清楚下在C++中 char **&ppcZHMSG 是不是等价于 char *ppcZHMSG ?
如果是
[DllImport("VCDLL.dll", EntryPoint="getAcctIDByNum",CallingConvention=CallingConvention.StdCall,CharSet=CharSet.Ansi)]
static extern short getAcctIDByNumstring pcDHHM, ref string ppcZHMSG, ref string ppcZHID);
应该就是正确的了