转换。ToInt32(string, base)不会将基数转换为基数。它假设字符串包含一个以指定基数为底的有效数字，并转换为以10为基数。

所以你会得到一个错误，因为“8”不是一个以2为基数的有效数字。

String str = "1111";
String Ans = Convert.ToInt32(str, 2).ToString();

将显示15(1111以2为底= 15以10为底)

String str = "f000";
String Ans = Convert.ToInt32(str, 16).ToString();

将显示61440。

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;
    }
}

您的示例中有一个表示为字符串的整数。假设你的整数实际上是一个整数，你想把这个整数转换成二进制字符串。

int value = 8;
string binary = Convert.ToString(value, 2);

返回1000。

http://zamirsblog.blogspot.com/2011/10/convert-decimal-to-binary-in-c.html

    public string DecimalToBinary(string data)
    {
        string result = string.Empty;
        int rem = 0;
        try
        {
            if (!IsNumeric(data))
                error = "Invalid Value - This is not a numeric value";
            else
            {
                int num = int.Parse(data);
                while (num > 0)
                {
                    rem = num % 2;
                    num = num / 2;
                    result = rem.ToString() + result;
                }
            }
        }
        catch (Exception ex)
        {
            error = ex.Message;
        }
        return result;
    }

非常简单，没有额外的代码，只是输入，转换和输出。

using System;

namespace _01.Decimal_to_Binary
{
    class DecimalToBinary
    {
        static void Main(string[] args)
        {
            Console.Write("Decimal: ");
            int decimalNumber = int.Parse(Console.ReadLine());

            int remainder;
            string result = string.Empty;
            while (decimalNumber > 0)
            {
                remainder = decimalNumber % 2;
                decimalNumber /= 2;
                result = remainder.ToString() + result;
            }
            Console.WriteLine("Binary:  {0}",result);
        }
    }
}

在c#中从任何经典基转换为任何基

string number = "100";
int fromBase = 16;
int toBase = 10;

string result = Convert.ToString(Convert.ToInt32(number, fromBase), toBase);

// result == "256"

支持的基数是2,8,10和16

    // I use this function
    public static string ToBinary(long number)
    {
        string digit = Convert.ToString(number % 2);
        if (number >= 2)
        {
            long remaining = number / 2;
            string remainingString = ToBinary(remaining);
            return remainingString + digit;
        }
        return digit;
     }

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

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;
}

原始的方法:

public string ToBinary(int n)
{
    if (n < 2) return n.ToString();

    var divisor = n / 2;
    var remainder = n % 2;

    return ToBinary(divisor) + remainder;
}

class Program
{
    static void Main(string[] args)
    {
        var @decimal = 42;
        var binaryVal = ToBinary(@decimal, 2);

        var binary = "101010";
        var decimalVal = ToDecimal(binary, 2);

        Console.WriteLine("Binary value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of binary '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();

        @decimal = 6;
        binaryVal = ToBinary(@decimal, 3);

        binary = "20";
        decimalVal = ToDecimal(binary, 3);

        Console.WriteLine("Base3 value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of base3 '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();


        @decimal = 47;
        binaryVal = ToBinary(@decimal, 4);

        binary = "233";
        decimalVal = ToDecimal(binary, 4);

        Console.WriteLine("Base4 value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of base4 '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();

        @decimal = 99;
        binaryVal = ToBinary(@decimal, 5);

        binary = "344";
        decimalVal = ToDecimal(binary, 5);

        Console.WriteLine("Base5 value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of base5 '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();

        Console.WriteLine("And so forth.. excluding after base 10 (decimal) though :)");
        Console.WriteLine();


        @decimal = 16;
        binaryVal = ToBinary(@decimal, 11);

        binary = "b";
        decimalVal = ToDecimal(binary, 11);

        Console.WriteLine("Hexidecimal value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of Hexidecimal '{0}' is {1}", binary, decimalVal);
        Console.WriteLine();
        Console.WriteLine("Uh oh.. this aint right :( ... but let's cheat :P");
        Console.WriteLine();

        @decimal = 11;
        binaryVal = Convert.ToString(@decimal, 16);

        binary = "b";
        decimalVal = Convert.ToInt32(binary, 16);

        Console.WriteLine("Hexidecimal value of decimal {0} is '{1}'", @decimal, binaryVal);
        Console.WriteLine("Decimal value of Hexidecimal '{0}' is {1}", binary, decimalVal);

        Console.ReadLine();
    }


    static string ToBinary(decimal number, int @base)
    {
        var round = 0;
        var reverseBinary = string.Empty;

        while (number > 0)
        {
            var remainder = number % @base;
            reverseBinary += remainder;

            round = (int)(number / @base);
            number = round;
        }

        var binaryArray = reverseBinary.ToCharArray();
        Array.Reverse(binaryArray);

        var binary = new string(binaryArray);
        return binary;
    }

    static double ToDecimal(string binary, int @base)
    {
        var val = 0d;

        if (!binary.All(char.IsNumber))
            return 0d;

        for (int i = 0; i < binary.Length; i++)
        {
            var @char = Convert.ToDouble(binary[i].ToString());

            var pow = (binary.Length - 1) - i;
            val += Math.Pow(@base, pow) * @char;
        }

        return val;
    }
}

学习资源:

你需要知道的关于二进制的一切

包括算法转换十进制到二进制

        static void Main(string[] args) 
        {
        Console.WriteLine("Enter number for converting to binary numerical system!");
        int num = Convert.ToInt32(Console.ReadLine());
        int[] arr = new int[16];

        //for positive integers
        if (num > 0)
        {

            for (int i = 0; i < 16; i++)
            {
                if (num > 0)
                {
                    if ((num % 2) == 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 0;
                    }
                    else if ((num % 2) != 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 1;
                    }
                }
            }
            for (int y = 0; y < 16; y++)
            {
                Console.Write(arr[y]);
            }
            Console.ReadLine();
        }

        //for negative integers
        else if (num < 0)
        {
            num = (num + 1) * -1;

            for (int i = 0; i < 16; i++)
            {
                if (num > 0)
                {
                    if ((num % 2) == 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 0;
                    }
                    else if ((num % 2) != 0)
                    {
                        num = num / 2;
                        arr[16 - (i + 1)] = 1;
                    }
                }
            }

            for (int y = 0; y < 16; y++)
            {
                if (arr[y] != 0)
                {
                    arr[y] = 0;
                }
                else
                {
                    arr[y] = 1;
                }
                Console.Write(arr[y]);
            }
            Console.ReadLine();
        }           
    }

BCL提供转换。ToString(n, 2)是很好的，但如果你需要一个替代的实现比BCL提供的快几个节拍。

下面的自定义实现适用于所有整数(-ve和+ve)。 原始来源来自https://davidsekar.com/algorithms/csharp-program-to-convert-decimal-to-binary

static string ToBinary(int n)
{
    int j = 0;
    char[] output = new char[32];

    if (n == 0)
        output[j++] = '0';
    else
    {
        int checkBit = 1 << 30;
        bool skipInitialZeros = true;
        // Check the sign bit separately, as 1<<31 will cause
        // +ve integer overflow
        if ((n & int.MinValue) == int.MinValue)
        {
            output[j++] = '1';
            skipInitialZeros = false;
        }

        for (int i = 0; i < 31; i++, checkBit >>= 1)
        {
            if ((n & checkBit) == 0)
            {
                if (skipInitialZeros)
                    continue;
                else
                    output[j++] = '0';
            }
            else
            {
                skipInitialZeros = false;
                output[j++] = '1';
            }
        }
    }

    return new string(output, 0, j);
}

以上代码是我的实现。所以，我渴望听到任何反馈:)

    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 );
}

这个函数在c#中将整数转换为二进制:

public static string ToBinary(int N)
{
    int d = N;
    int q = -1;
    int r = -1;

    string binNumber = string.Empty;
    while (q != 1)
    {
        r = d % 2;
        q = d / 2;
        d = q;
        binNumber = r.ToString() + binNumber;
    }
    binNumber = q.ToString() + binNumber;
    return binNumber;
}

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);

如果你想要一个简洁的函数，你可以从你的主方法调用，在你的类中，这可能是有帮助的。如果你需要一个数字而不是字符串，你可能仍然需要调用int.Parse(toBinary(someint))，但我发现这个方法工作得很好。此外，如果您愿意，还可以调整为使用for循环而不是do-while循环。

    public static string toBinary(int base10)
    {
        string binary = "";
        do {
            binary = (base10 % 2) + binary;
            base10 /= 2;
        }
        while (base10 > 0);

        return binary;
    }

toBinary(10)返回字符串“1010”。

    static void convertToBinary(int n)
    {
        Stack<int> stack = new Stack<int>();
        stack.Push(n);
        // step 1 : Push the element on the stack
        while (n > 1)
        {
            n = n / 2;
            stack.Push(n);
        }

        // step 2 : Pop the element and print the value
        foreach(var val in stack)
        {
            Console.Write(val % 2);
        }
     }

我在一个编码挑战中遇到了这个问题，你必须将32位十进制转换为二进制，并找到子字符串的可能组合。

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Numerics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    class Program
    {

        public static void Main()
        {
            int numberofinputs = int.Parse(Console.ReadLine());
            List<BigInteger> inputdecimal = new List<BigInteger>();
            List<string> outputBinary = new List<string>();


            for (int i = 0; i < numberofinputs; i++)
            {
                inputdecimal.Add(BigInteger.Parse(Console.ReadLine(), CultureInfo.InvariantCulture));
            }
            //processing begins 

            foreach (var n in inputdecimal)
            {
                string binary = (binaryconveter(n));
                subString(binary, binary.Length);
            }

            foreach (var item in outputBinary)
            {
                Console.WriteLine(item);
            }

            string binaryconveter(BigInteger n)
            {
                int i;
                StringBuilder output = new StringBuilder();

                for (i = 0; n > 0; i++)
                {
                    output = output.Append(n % 2);
                    n = n / 2;
                }

                return output.ToString();
            }

            void subString(string str, int n)
            {
                int zeroodds = 0;
                int oneodds = 0;

                for (int len = 1; len <= n; len++)
                {

                    for (int i = 0; i <= n - len; i++)
                    {
                        int j = i + len - 1;

                        string substring = "";
                        for (int k = i; k <= j; k++)
                        {
                            substring = String.Concat(substring, str[k]);

                        }
                        var resultofstringanalysis = stringanalysis(substring);
                        if (resultofstringanalysis.Equals("both are odd"))
                        {
                            ++zeroodds;
                            ++oneodds;
                        }
                        else if (resultofstringanalysis.Equals("zeroes are odd"))
                        {
                            ++zeroodds;
                        }
                        else if (resultofstringanalysis.Equals("ones are odd"))
                        {
                            ++oneodds;
                        }

                    }
                }
                string outputtest = String.Concat(zeroodds.ToString(), ' ', oneodds.ToString());
                outputBinary.Add(outputtest);
            }

            string stringanalysis(string str)
            {
                int n = str.Length;

                int nofZeros = 0;
                int nofOnes = 0;

                for (int i = 0; i < n; i++)
                {
                    if (str[i] == '0')
                    {
                        ++nofZeros;
                    }
                    if (str[i] == '1')
                    {
                        ++nofOnes;
                    }

                }
                if ((nofZeros != 0 && nofZeros % 2 != 0) && (nofOnes != 0 && nofOnes % 2 != 0))
                {
                    return "both are odd";
                }
                else if (nofZeros != 0 && nofZeros % 2 != 0)
                {
                    return "zeroes are odd";
                }
                else if (nofOnes != 0 && nofOnes % 2 != 0)
                {
                    return "ones are odd";
                }
                else
                {
                    return "nothing";
                }

            }
            Console.ReadKey();
        }

    }
}

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;

var b = Convert.ToString(i,2).PadLeft(32,'0').ToCharArray().Reverse().ToArray();

8位的只有一行

Console.WriteLine(Convert.ToString(n, 2).PadLeft(8, '0'));

n在哪里