对于int，memcpy数组的C＃等价物是什么？

Question

EDIT: I'm considering this question different from the potential duplicate because none of the answers on that one contain the approach I went with which is the BitConverter class. In case me marking this as not a duplicate gets rid of the potential duplicate question link here it is .

I'm wondering what the c# equivalent of this code is considering each element in the array is a byte and it's getting copied to an int.

byte offsetdata[sizeof(int)] = { 0,0,0,0 };
offsetdata[0] = m_Response[responseIndex++];
offsetdata[1] = m_Response[responseIndex++];
offsetdata[2] = m_Response[responseIndex++];
offsetdata[3] = m_Response[responseIndex++];
int offset = 0;
memcpy(&offset, offsetdata, sizeof offset);
m_ZOffset = offset;

Answer 1

This is possibly a duplicate, but I don't know how to mark it. Here is the original post: memcpy function in c#

From the other post there appear to be several options:

1. Array.Copy
2. Object.MemberwiseClone
3. ICloneable Interface

Answer 2

It really seems you just want to use

• BitConverter.ToInt32 Method

Returns a 32-bit signed integer converted from four bytes at a specified position in a byte array

int offset =  BitConverter.ToInt32(somebyteData,0);

_{Note : Beware of the endianness}

Or you could just use the the shift operators

• << operator (C# Reference)

• <<= operator (C# Reference)

• >> operator (C# Reference)

• >>= operator (C# Reference)

Though if you want to use memcpy , It depends what overloads you need, you can just P/invoke it if you want

[DllImport("msvcrt.dll", EntryPoint = "memcpy", CallingConvention = CallingConvention.Cdecl, SetLastError = false)]
public static extern IntPtr memcpy(IntPtr dest, IntPtr src, UIntPtr count);

However, for pointers the last 2 are probably good equivalents, with Marshal.Copy having by far the most versatility

• Buffer.BlockCopy

Copies a specified number of bytes from a source array starting at a particular offset to a destination array starting at a particular offset.

• Array.Copy

Copies a range of elements in one Array to another Array and performs type casting and boxing as required.

• Unsafe.CopyBlock Method

Copies a number of bytes specified as a long integer value from one address in memory to another.

• Marshal.Copy

Copies data from a managed array to an unmanaged memory pointer, or from an unmanaged memory pointer to a managed array.

Answer 3

In c# you could do something like:

int offset = m_Response[responseIndex++];
offset <<= 8;
offset |= m_Response[responseIndex++];
offset <<= 8;
...

Finnally in offset you'll have every byte.