如何在vb.net窗口应用程序中切割数字？

Question

我想我的程序输入十进制将输出在4位小数通过不四舍五入在输入的号码

输入：0.6363636364

输出：0.6363

Answer 1

为了完整，因为OP请求VB解决方案，这里的基础上添劳埃德回答十进制扩展Truncate Two decimal places without rounding：

Module MyExtensions 
    <System.Runtime.CompilerServices.Extension> 
    Public Function TruncateDecimal(d As Decimal, decimals As Integer) As Decimal 
     Select Case True 
      Case decimals < 0 
       Throw New ArgumentOutOfRangeException("decimals", "Value must be in range 0-28.") 
      Case decimals > 28 
       Throw New ArgumentOutOfRangeException("decimals", "Value must be in range 0-28.") 
      Case decimals = 0 
       Return Math.Truncate(d) 
      Case Else 
       Dim IntegerPart As Decimal = Math.Truncate(d) 
       Dim ScalingFactor As Decimal = d - IntegerPart 
       Dim Multiplier As Decimal = Math.Pow(10, decimals) 

       ScalingFactor = Math.Truncate(ScalingFactor * Multiplier)/Multiplier 

       Return IntegerPart + ScalingFactor 
     End Select 
    End Function 
End Module 

用法：

Dim Value As Decimal = 0.6363636364 
Value = Value.TruncateDecimal(4)