C# how to get Byte[] from IntPtr

c# byte bytearray intptr
Gabriel picture Gabriel · Mar 30, 2011 · Viewed 83.6k times · Source

I have a .dll(not my own) that has a delegate. This delegate Callback function is:
"CallBackFN(ushort opCOde, IntPtr payload, uint size, uint localIP)"

How can i convert IntPtr to Byte[]? I think that payload is actually Byte[]. If it's not Byte[] and it's something else would i lose some data?

Answer

jlew picture jlew · Mar 30, 2011

If it's a byte[] array:

 byte[] managedArray = new byte[size];
 Marshal.Copy(pnt, managedArray, 0, size);

If it's not byte[], the size parameter in of Marshal.Copy is the number of elements in the array, not the byte size. So, if you had an int[] array rather than a byte[] array, you would have to divide by 4 (bytes per int) to get the correct number of elements to copy, assuming your size parameter passed through the callback refers to # of bytes.

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