Question

vb.net 如何给变量（double类）赋空值

Dim R08 As Double
If InStr(1, Mid(fileLines(2), 1, InStr(1, fileLines(2), ")")), st(p)) <> 0 Then
R08 = "0.0"
Else
R08 = Nothing
End If
instr为0时，赋值R08为空值，但显示出结果是默认的 0，要如何给R08赋值空，

Answer 1

Dim R08 As Nullable(Of Double)
If InStr(1, Mid(fileLines(2), 1, InStr(1, fileLines(2), ")")), st(p)) <> 0 Then
                            R08 = 0
                        Else
                            R08 = Nothing
                        End If