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Convert BitArray to byte

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Kabanga	5 Nov, 2009 - 10:42 PM Post #1
New D.I.C Head Joined: 5 Mar, 2009 Posts: 16	Hi everyone! I have a BitArray defined as follow: CODE //create an array of 256 boolean elements bool[] myStates = new bool[256]; //create BitArray from the array myStates BitArray myNewStates = new BitArray(myStates); and an array of bytes defined like that: CODE //create an array of 65 bytes Byte[] myBuffer = new byte[65]; //initialize the first 5 bytes myBuffer[0] = 0x00; myBuffer[1] = 0x01; myBuffer[2] = 0x02; myBuffer[3] = 0x03; myBuffer[4] = 0x04; //initialize array 38 to 65 for(int i=38; i<65; i++) { myBuffer[i] = oxFF; } Now I'd like to populate bytes 6 to 37 (a total of 32 bytes) of myBuffer array using the BitArray myNewStates. Since 256 bits (true, false states) is equivalent to 32 bytes, how to convert these boolean states into bytes? Best regards Kabanga
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djkitt	RE: Convert BitArray To Byte 6 Nov, 2009 - 07:32 AM Post #2
D.I.C Head Joined: 22 May, 2008 Posts: 174 Thanked: 24 times My Contributions	So, You could try the CopyTo method... CODE myNewStates.CopyTo(myBuffer, 6); Hope this helps, Kitt
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Momerath	RE: Convert BitArray To Byte 6 Nov, 2009 - 09:18 AM Post #3
D.I.C Addict Joined: 4 Oct, 2009 Posts: 509 Thanked: 52 times My Contributions	Depends on how you want to copy the bits over. For example in an 8 position BitArray, they are in this order 76543210. But it's possible that you want them in the Bytes in order from low to high, or in reverse order (where the last byte in the byte list is the lowest indexes).
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Kabanga	RE: Convert BitArray To Byte 6 Nov, 2009 - 11:12 PM Post #4
New D.I.C Head Joined: 5 Mar, 2009 Posts: 16	thanks guys, it was helpful! @ Momerath yeah, your are right: I'd like them to be in the order 01234567. How to do that?. In the Bytes I'd like the last byte in the list have the highest index. Best regards Kabanga
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Momerath

RE: Convert BitArray To Byte

6 Nov, 2009 - 11:30 PM

Post #5

D.I.C Addict

Joined: 4 Oct, 2009
Posts: 509

Thanked: 52 times
My Contributions

csharp

public byte[] BitArrayToByteArray(BitArray ba) {
	byte[] bytes;

	if (ba.Length % 8 == 0) {
		bytes = new byte[ba.Length / 8];
	} else {
		bytes = new byte[ba.Length / 8 + 1];
	}

	for (int i = 0; i < ba.Length; i += 8) {
		int pos = i / 8;

		for (int j = 0; j < 8; j++) {
			if (i + j < ba.Length) {
				if (ba[i + j] == true) {
					bytes[pos] &= 1;
				}
			}
			bytes[pos] <<= 1;
		}
	}

	return bytes;
}

This is off the top of my head, I can already see some ways to improve it

This post has been edited by Momerath: 6 Nov, 2009 - 11:33 PM

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Kabanga	RE: Convert BitArray To Byte 7 Nov, 2009 - 11:07 AM Post #6
New D.I.C Head Joined: 5 Mar, 2009 Posts: 16	thanks. I'll give it a try! Which improvements do you mean? Best regards Kabanga This post has been edited by Kabanga: 7 Nov, 2009 - 11:09 AM
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