VB.NET数学操作(大型添加)

Question

你好，我需要一些帮助，以尝试添加两个大数字：例如：我正在使用BigInteger进行操作，但是在值太大之后我会得到此错误：

这是我的代码：

    Dim one As System.Numerics.BigInteger = message.Text
    Dim two As System.Numerics.BigInteger = mykey.Text
    System.Numerics.BigInteger.TryParse(message.Text, two)
    sum.Text = (one + two).ToString

Answer 1

您的代码实际上没有意义。我刚刚测试了这样的两个BigInteger值的添加：

Dim one As BigInteger = BigInteger.Parse("99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999")
Dim two As BigInteger = BigInteger.Parse("9999999999999999999999999999999999999999999999999999999999999999999999999")
Console.WriteLine((one + two).ToString)
Console.ReadLine()

这样：

Dim str1 = "99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999"
Dim str2 = "9999999999999999999999999999999999999999999999999999999999999999999999999"
Dim one As BigInteger
Dim two As BigInteger
BigInteger.TryParse(str1, one)
BigInteger.TryParse(str2, two)
Console.WriteLine((one + two).ToString)
Console.ReadLine()

它的工作正常与预期的两次。

您确实需要转动Option Strict On，因为您的代码将String值分配给BigInteger变量，这几乎可以肯定是导致您的问题的原因。如果您有要转换为BigInteger的String，则在已知值有效时应使用BigInteger.Parse，或者当该值不为BigInteger.TryParse时。

您的代码并没有真正的意义，因为您首先假设隐式转换可以，但是随后您继续使用TryParse。它变得更加荒谬，因为您使用TryParse来填充看似错误的BigInteger变量。您需要了解您的代码在写作之前应该做什么，否则您最终会胡说八道，并且不知道它不做您不知道您想做的事情。