c＃如何将float转换为int

Question

I need to convert float to int (single precision, 32 bits) like:
'float: 2 (hex: 40000000) to int: 1073741824'. Any idea how to implement that?
I was looking for it in msdn help but with no result.

Answer 1

float f = ...;
int i = BitConverter.ToInt32(BitConverter.GetBytes(f), 0);

Answer 2

BitConverter.DoubleToInt64Bits , as per the accepted answer of this question .

If the above solution is no good for you (due to it acting upon double / Double rather than float / Single ) then see David Heffernan's answer .

Answer 3

David THANKS, that was a short answer of my long search of analogue for Java method: Float.floatToIntBits. Here is the entire code:

static void Main()
{

    float tempVar = -27.25f;

    int intBits = BitConverter.ToInt32(BitConverter.GetBytes(tempVar), 0);
    string input = Convert.ToString(intBits, 2);
    input = input.PadLeft(32, '0');
    string sign = input.Substring(0, 1);
    string exponent = input.Substring(1, 8);
    string mantissa = input.Substring(9, 23);

    Console.WriteLine();
    Console.WriteLine("Sign = {0}", sign);
    Console.WriteLine("Exponent = {0}", exponent);
    Console.WriteLine("Mantissa = {0}", mantissa);
}

Answer 4

If your aiming for versions less than .Net 4 where BitConverter isn't available, or you want to convert floats to 32 bit ints, use a memory stream:

using System;
using System.IO;

namespace Stream
{
  class Program
  {
    static void Main (string [] args)
    {
      float
        f = 1;

      int
        i;

      MemoryStream
        s = new MemoryStream ();

      BinaryWriter
        w = new BinaryWriter (s);

      w.Write (f);

      s.Position = 0;

      BinaryReader
        r = new BinaryReader (s);

      i = r.ReadInt32 ();

      s.Close ();

      Console.WriteLine ("Float " + f + " = int " + i);
    }
  }
}

It is a bit long winded though.