C# how to get Byte[] from IntPtr
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?
Solution 1:
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 the number of bytes.
Solution 2:
Have you looked into Marshal.Copy?
http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.marshal.copy.aspx
Solution 3:
If you need performance, use it directly:
unsafe {
byte *ptr = (byte *)buffer.ToPointer();
int offset = 0;
for (int i=0; i<height; i++)
{
for (int j=0; j<width; j++)
{
float b = (float)ptr[offset+0] / 255.0f;
float g = (float)ptr[offset+1] / 255.0f;
float r = (float)ptr[offset+2] / 255.0f;
float a = (float)ptr[offset+3] / 255.0f;
offset += 4;
UnityEngine.Color color = new UnityEngine.Color(r, g, b, a);
texture.SetPixel(j, height-i, color);
}
}
}