Vb.net 简化select case语句以避免干燥

如何重构此代码以避免重复？特别是如果有更多的情况！我读过关于用词汇简化某些案例的书，但我不知道如何在这种情况下使用它。有什么建议吗

    Dim sPath As String = String.Empty
    Dim aThing As Decimal

    Select Case True
        Case (aThing < 7.5)
            sPath = "~/images/Grafik_7.5.png"
        Case (aThing >= 7.5 AndAlso aThing < 8.75)
            sPath = "~/images/Grafik_18.75.png"
        Case (aThing >= 58.75 AndAlso aThing < 60)
            sPath = "~/images/Grafik_60.png"
        Case (aThing >= 60 AndAlso aThing < 61.25)
            sPath = "~/images/Grafik_61.25.png"
        Case (aThing >= 61.25 AndAlso aThing < 62.5)
            sPath = "~/images/Grafik_62.5.png"
        Case (aThing >= 62.5 AndAlso aThing < 63.75)
            sPath = "~/images/Grafik_63.75.png"
        Case (aThing >= 63.75 AndAlso aThing < 65)
            sPath = "~/images/Grafik_65.png"
        Case (aThing >= 65 AndAlso aThing < 66.25)
            sPath = "~/images/Grafik_66.25.png"
        Case (aThing >= 66.25)
            sPath = "~/images/Grafik_67.5.png"
    End Select

Dim sPath As String=String.Empty
十进制的
选择Case True
病例（aThing<7.5）
sPath=“~/images/Grafik_7.5.png”
案例（aThing>=7.5，aThing<8.75）
sPath=“~/images/Grafik_18.75.png”
案例（aThing>=58.75，且aThing<60）
sPath=“~/images/Grafik_60.png”
案例（aThing>=60且aThing<61.25）
sPath=“~/images/Grafik_61.25.png”
案例（aThing>=61.25，且aThing<62.5）
sPath=“~/images/Grafik_62.5.png”
案例（aThing>=62.5，且aThing<63.75）
sPath=“~/images/Grafik_63.75.png”
案例（aThing>=63.75，且aThing<65）
sPath=“~/images/Grafik_65.png”
案例（aThing>=65，且aThing<66.25）
sPath=“~/images/Grafik_66.25.png”
案例（aThing>=66.25）
sPath=“~/images/Grafik_67.5.png”
结束选择

这可能需要根据最大数值的大小稍微改变，但我的想法是这样的：

    Dim values = {7.5D, 18.75D, 60D, 61.25D} 'etc.
    Dim value = values.First(Function(x) x > aThing)

    sPath = $"~images/Grafik_{value}.png

Dim conditions = new Dictionary(of Predicate(of Double), String) From
{
    {Function(a) a < 7.5, "Grafik_7.5.png"},
    {Function(a) a >= 7.5 AndAlso a <= 8.75, "Grafik_8.75.png"},
    {Function(a) a >= 58.75 AndAlso a < 60, "Grafik_60.png"} 
}

Dim aThing = 8.3
Dim result = conditions.Single(Function (c) c.Key(aThing)).Value

Dim sizes = new List(Of Double) From {7.5, 8.75, 60, 61.25} 

Dim InvC = System.Globalization.CultureInfo.InvariantCulture
DIm size = sizes.First(Function(s) s > aThing).ToString(InvC)

Dim result = "Grafik_" + size + ".png"

---

使用字典，您可以这样做：

    Dim values = {7.5D, 18.75D, 60D, 61.25D} 'etc.
    Dim value = values.First(Function(x) x > aThing)

    sPath = $"~images/Grafik_{value}.png

Dim conditions = new Dictionary(of Predicate(of Double), String) From
{
    {Function(a) a < 7.5, "Grafik_7.5.png"},
    {Function(a) a >= 7.5 AndAlso a <= 8.75, "Grafik_8.75.png"},
    {Function(a) a >= 58.75 AndAlso a < 60, "Grafik_60.png"} 
}

Dim aThing = 8.3
Dim result = conditions.Single(Function (c) c.Key(aThing)).Value

Dim sizes = new List(Of Double) From {7.5, 8.75, 60, 61.25} 

Dim InvC = System.Globalization.CultureInfo.InvariantCulture
DIm size = sizes.First(Function(s) s > aThing).ToString(InvC)

Dim result = "Grafik_" + size + ".png"

---

如果您确实想坚持使用

选择案例

，那么在每个

案例

上指定一个下限是没有意义的，因为您已经通过不匹配以前的任何案例来保证满足这一要求。您应该使用

不变量文化

；否则，根据此代码运行的机器的区域性设置，

sPath

可能是例如

…Grafik_18,75.png

而不是

…Grafik_18.75.png

这确实是真的，但我确实说过类似的话。