将范围链接到集合中的项目

Question

我有一个这样的集合

Private Shared ReadOnly thermoPaths As New ReadOnlyCollection(Of String) _
({
   "thermometer_000_108x320.jpg",
   "thermometer_010_108x320.jpg",
   "thermometer_020_108x320.jpg",
   "thermometer_030_108x320.jpg",
   "thermometer_040_108x320.jpg",
   "thermometer_050_108x320.jpg",
   "thermometer_060_108x320.jpg",
   "thermometer_070_108x320.jpg",
   "thermometer_080_108x320.jpg",
   "thermometer_090_108x320.jpg",
   "thermometer_100_108x320.jpg"
})

，并希望将 1 到 100 之间的十进制值链接到我的集合中的相应项目。

所以基本上我想要实现的目标就是这个。

Select Case Decimal.Round(value)
    Case 1 To 9
        Dim x As String = thermoPaths(0)
    Case 10 To 19
        Dim x As String = thermoPaths(1)
    Case 20 To 29
        Dim x As String = thermoPaths(2)
    Case 30 To 39
        Dim x As String = thermoPaths(3)
    case ''AND SO ON
End Select

但我确信一定有一种“更干净”的方式来做到这一点？

Answer 1

只需除以四舍五入即可得到索引。

i = Math.Ceiling(value / 10)
If value >= 0 AndAlso i < thermoPaths.Count Then
    path = thermoPaths(i)
Else
    path = Nothing
End If

一些测试点：

value   i   path
 -1     0   <null> (because value < 0)
  0     0   thermometer_000_108x320.jpg
  1     1   thermometer_010_108x320.jpg
  5     1   thermometer_010_108x320.jpg
 10     1   thermometer_010_108x320.jpg
 49     5   thermometer_050_108x320.jpg
 51     6   thermometer_060_108x320.jpg
 90     9   thermometer_090_108x320.jpg
 91    10   thermometer_100_108x320.jpg
100    10   thermometer_100_108x320.jpg
101    11   <null> (because i > 10)

Answer 2

将值除以 10，然后得到该值的下限，应该会给出适当的指数。