Question

我有一个将字节转换为8位地址的函数，并返回参数中指定位置的位。

它的构建方式现在运行正常，但在我看来它是非常丑陋的，有一种方法可以用数学方法或那个方向做一些事情，我试着找另一个方法，但没有想出任何东西。

    private bool ConvertByteToBitAddres(byte byteToConvert, int bitToReturn)
    {
        bool[] address = new bool[8];
        int remaining = byteToConvert;


        if (remaining > 128)
        {
            remaining = remaining - remaining;
            address[7] = true;
        }
        if (remaining > 64 || remaining < 128)
        {
            remaining = remaining - remaining;
            address[6] = true;
        }
        if (remaining > 32)
        {
            remaining = remaining - remaining;
            address[5] = true;
        }
        if (remaining > 16)
        {
            remaining = remaining - remaining;
            address[4] = true;
        }
        if (remaining > 8)
        {
            remaining = remaining - remaining;
            address[3] = true;
        }
        if (remaining > 4)
        {
            remaining = remaining - remaining;
            address[2] = true;
        }
        if (remaining > 2)
        {
            remaining = remaining - remaining;
            address[1] = true;
        }
        if (remaining > 1)
        {
            remaining = remaining - remaining;
            address[0] = true;
        }

        if (remaining == 0)
        {
            return address[bitToReturn];
        }
        throw new Exception();
    }

提前致谢。

Answer 1

使用位掩码。

private bool ConvertByteToBitAddres(byte byteToConvert, int bitToReturn)
{
    int mask = 1 << bitToReturn;
    return (byteToConvert & mask) == mask;
}

Answer 2

使用按位运算;例如：

int mask = 1 << (bitToReturn - 1); // if "bitToReturn" is 1-based
// int mask = 1 << bitToReturn; // if "bitToReturn" is 0-based
return (byteToConvert & mask) != 0

或许更容易传递mask而不是bitToReturn。

Answer 3

另一个可能适用的选项是使用BitVector32：

byte b = 10;
var bv = new BitVector32(b);

for (int i = 0; i < 8; i++)
{
    Console.WriteLine($"Value of bit {i}:  {bv[1 << i]}");
}

//You could also declare consts for each bit and use that:
const int Bit0 = 1;
const int Bit1 = 2;
const int Bit2 = 4;
const int Bit3 = 8;

Console.WriteLine($"\r\nValue of bit 3:  {bv[Bit3]}");

输出：

Value of bit 0:  False
Value of bit 1:  True 
Value of bit 2:  False
Value of bit 3:  True 
Value of bit 4:  False 
Value of bit 5:  False
Value of bit 6:  False 
Value of bit 7:  False

Value of bit 3:  True

从字节值返回特定位作为布尔值

3 个答案: