Got hit by an OverflowException

In the Method below on the last line I'm always getting an exception:

System.OverflowException: Value was either too large or too small for an Int32.

I can't really explain why because I'm checking explicitly for that:

private Int32 ConvertValue(double value)
{
   if (value > Int32.MaxValue)
   {
      Console.WriteLine("Couldn't convert value " + value + " to Int32");
      return Int32.MaxValue;
   }
   else if (value < Int32.MinValue)
   {
      Console.WriteLine("Couldn't convert value " + value + " to Int32");
      return Int32.MinVal开发者_运维问答ue;
   }
   else
   {
      return Convert.ToInt32(value);
   }
}

Also check double.IsNaN(value).

Compares with NaN always yield false.

Here's the source from Microsoft's Convert.cs:

public static int ToInt32(double value) {
    if (value >= 0) {
        if (value < 2147483647.5) {
            int result = (int)value; 
            double dif = value - result;
            if (dif > 0.5 || dif == 0.5 && (result & 1) != 0) result++; 
            return result; 
        }
    } 
    else {
        if (value >= -2147483648.5) {
            int result = (int)value;
            double dif = value - result; 
            if (dif < -0.5 || dif == -0.5 && (result & 1) != 0) result--;
            return result; 
        } 
    }
    throw new OverflowException(Environment.GetResourceString("Overflow_Int32")); 
}

I don't know what value you are feeding it, but the answer should be obvious now.

You get the exception every time you run this function with any double value?

It worked fine for me.

Edit: I created a program with the following code:

using System;
using System.Collections.Generic;
using System.Text;

namespace test1
{
    class Program
    {
        static void Main(string[] args)
        {
            Int32 myInt = ConvertValue(86389327923.678);
            Console.WriteLine(myInt);
                    myInt = ConvertValue(-86389327923.678);
            Console.WriteLine(myInt);
                    myInt = ConvertValue(8.678);
            Console.WriteLine(myInt);
            Console.ReadKey();
        }

        static private Int32 ConvertValue(double value)
        {
            if (value > Int32.MaxValue)
            {
                Console.WriteLine("Couldn't convert value " + value + " to Int32");
                return Int32.MaxValue;
            }
            else if (value < Int32.MinValue)
            {
                Console.WriteLine("Couldn't convert value " + value + " to Int32");
                return Int32.MinValue;
            }
            else
            {
                return Convert.ToInt32(value);
            }
        }
    }
}