class Program{

   static void Main(string[] args){

      try{

     int i = (int)Convert.ToInt64(args[0]);
         Console.WriteLine("\n{0} converted to Binary is {1}\n",i,ToBinary(i));

      }catch(Exception e){

         Console.WriteLine("\n{0}\n",e.Message);

      }

   }//end Main


        public static string ToBinary(Int64 Decimal)
        {
            // Declare a few variables we're going to need
            Int64 BinaryHolder;
            char[] BinaryArray;
            string BinaryResult = "";

            while (Decimal > 0)
            {
                BinaryHolder = Decimal % 2;
                BinaryResult += BinaryHolder;
                Decimal = Decimal / 2;
            }

            // The algoritm gives us the binary number in reverse order (mirrored)
            // We store it in an array so that we can reverse it back to normal
            BinaryArray = BinaryResult.ToCharArray();
            Array.Reverse(BinaryArray);
            BinaryResult = new string(BinaryArray);

            return BinaryResult;
        }


}//end class Program

这是一个有趣的阅读，我正在寻找一个快速复制粘贴。 我知道我很久以前用bitmath做过这件事。

以下是我的看法。

// i had this as a extension method in a static class (this int inValue);

public static string ToBinaryString(int inValue)
{
    string result = "";
    for (int bitIndexToTest = 0; bitIndexToTest < 32; bitIndexToTest++)
        result += ((inValue & (1 << (bitIndexToTest))) > 0) ? '1' : '0';
    return result;
}

你可以在循环中加入一些模数。

        // little bit of spacing
        if (((bitIndexToTest + 1) % spaceEvery) == 0)
            result += ' ';

你可能会使用或传入一个stringbuilder，并直接追加或索引，以避免释放，也可以绕过+=的使用;

使用Enumerable和LINQ的另一个可选的内联解决方案是:

int number = 25;
    
string binary = Enumerable.Range(0, (int)Math.Log(number, 2) + 1).Aggregate(string.Empty, (collected, bitshifts) => ((number >> bitshifts) & 1 ) + collected);

我知道这个答案看起来与这里的大多数答案相似，但我注意到它们几乎都没有使用for循环。这段代码可以工作，并且可以被认为是简单的，因为它不需要任何特殊的函数就可以工作，就像带参数的ToString()一样，而且也不太长。也许有些人更喜欢for-loop而不是while-loop，这可能适合他们。

public static string ByteConvert (int num)
{
    int[] p = new int[8];
    string pa = "";
    for (int ii = 0; ii<= 7;ii = ii +1)
    {
        p[7-ii] = num%2;
        num = num/2;
    }
    for (int ii = 0;ii <= 7; ii = ii + 1)
    {
        pa += p[ii].ToString();
    }
    return pa;
}

    int x=550;
    string s=" ";
    string y=" ";

    while (x>0)
    {

        s += x%2;
        x=x/2;
    }


    Console.WriteLine(Reverse(s));
}

public static string Reverse( string s )
{
    char[] charArray = s.ToCharArray();
    Array.Reverse( charArray );
    return new string( charArray );
}

using System;

class Program 
{
    static void Main(string[] args) {

        try {

            int i = (int) Convert.ToInt64(args[0]);
            Console.WriteLine("\n{0} converted to Binary is {1}\n", i, ToBinary(i));

        } catch(Exception e) {
            Console.WriteLine("\n{0}\n", e.Message);
        }
    }

    public static string ToBinary(Int64 Decimal) {
        // Declare a few variables we're going to need
        Int64 BinaryHolder;
        char[] BinaryArray;
        string BinaryResult = "";

        while (Decimal > 0) {
            BinaryHolder = Decimal % 2;
            BinaryResult += BinaryHolder;
            Decimal = Decimal / 2;
        }

        BinaryArray = BinaryResult.ToCharArray();
        Array.Reverse(BinaryArray);
        BinaryResult = new string(BinaryArray);

        return BinaryResult;
    }
}