Silverlight没有Math.Truncate!......这个等同的工作吗？

Question

Math.Truncate在大多数情况下,这是否相同:

double x = 1034.45
var truncated = x - Math.Floor(Math.Abs(x));

哪里truncated == 0.45？

更新中...

感谢输入人!这对我有用:

[TestMethod]
public void ShouldTruncateNumber()
{
    double x = -1034.068;
    double truncated = ((x < 0) ? -1 : 1) * Math.Floor(Math.Abs(x));

    Assert.AreEqual(Math.Truncate(x), truncated, "The expected truncated number is not here");
}

这个也是:

[TestMethod]
public void ShouldGetMantissa()
{
    double x = -1034.068;
    double mantissaValue = ((x < 0) ? -1 : 1) *
        (Math.Abs(x) - Math.Floor(Math.Abs(x)));
    mantissaValue = Math.Round(mantissaValue, 2);

    Assert.AreEqual(-0.07, mantissaValue, "The expected mantissa decimal is not here");
}

Answer 1

您truncated将无法获得负值的正确值x.

要使用Math.Floor像Truncate一样向零舍入,只需这样做;

static double Truncate(double d)
{
    return d > 0 ? Math.Floor(d) : -Math.Floor(-d);
}