C# Bug --强制类型转换

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下面是一段非常简单的C#源码，程序中首先定义单精度浮点数f，并对其进行赋值，运算后取整转换，最后输出计算结果，1.3*100取整后应为130，但程序给出的结果为129。

 

using System;

namespace testPro

{

    class Program

    {

        static void Main()

        {

            float f = 1.3F; //step 1

            int ret = (int)(f * 100); //step 2

            Console.WriteLine(ret);//step 3

//result is 129 !!!!!!!!!!! why??

        }

    }

}

如果将step  2分解为以下两条语句，则结果为130。

              float temp = f * 100;

        int ret = (int)temp;

 

测试环境：

Windows Server 2003

Visual Studio 2005(8.050727)

Microsoft .NET Framework 2.0.50727