Question

我有这个程序，你可以制作一系列动作。这些操作存储在本地SQLCe数据库中（一旦它工作，它将在真实的SQL Server中），并且每个操作可以有多个参数。这段代码目前有效，但我想知道用循环或锯齿状数组缩小它的最佳方法，这是我无法弄清楚的。

以下是代码：

Imports System.Data.SqlServerCe
Imports System.Text
Imports Microsoft.Win32

Public Class Form2
Dim conn As SqlCeConnection = New SqlCeConnection("Data Source=Database.sdf")

    Public Function Split(ByVal source As String) As Array

    Dim results() As String

    results = source.Split(",")

    Return results
    End Function

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim indexname As String = "Jagged Test"
    Dim scriptrestriction As String = ""
    Dim scriptid As String = ""
    Dim scripttype As String = ""

    Dim tempresult As String = ""

    Dim Arg0 As New List(Of String)()
    Dim Arg1 As New List(Of String)()
    Dim Arg2 As New List(Of String)()
    Dim Arg3 As New List(Of String)()
    Dim Arg4 As New List(Of String)()
    Dim Arg5 As New List(Of String)()
    Dim Arg6 As New List(Of String)()

    If conn.State = ConnectionState.Closed Then
        conn.Open()
    End If

    Dim sql As New SqlCeCommand("SELECT * FROM ScriptInfo WHERE Name = '" & indexname & "'", conn)
    Dim sdr As SqlCeDataReader = sql.ExecuteReader()

    While sdr.Read = True
        If Not IsDBNull(sdr.Item("Restriction")) Then
            scriptrestriction = sdr.Item("Restriction")
        End If
        If Not IsDBNull(sdr.Item("ID")) Then
            scriptid = sdr.Item("ID")
        End If
        If Not IsDBNull(sdr.Item("ScriptType")) Then
            scripttype = sdr.Item("ScriptType")
        End If

        tempresult = ""
        If Not IsDBNull(sdr.Item("Arg0")) Then
            tempresult = (sdr.Item("Arg0"))
            If tempresult.Contains(",") Then
                For Each s1 In (Split(tempresult))
                    Arg0.Add(s1)
                Next
            Else
                Arg0.Add(tempresult)
            End If
        End If

        tempresult = ""
        If Not IsDBNull(sdr.Item("Arg1")) Then
            tempresult = (sdr.Item("Arg1"))
            If tempresult.Contains(",") Then
                For Each s1 In (Split(tempresult))
                    Arg1.Add(s1)
                Next
            Else
                Arg1.Add(tempresult)
            End If
        End If

        tempresult = ""
        If Not IsDBNull(sdr.Item("Arg2")) Then
            tempresult = (sdr.Item("Arg2"))
            If tempresult.Contains(",") Then
                For Each s1 In (Split(tempresult))
                    Arg2.Add(s1)
                Next
            Else
                Arg2.Add(tempresult)
            End If
        End If

        tempresult = ""
        If Not IsDBNull(sdr.Item("Arg3")) Then
            tempresult = (sdr.Item("Arg3"))
            If tempresult.Contains(",") Then
                For Each s1 In (Split(tempresult))
                    Arg3.Add(s1)
                Next
            Else
                Arg3.Add(tempresult)
            End If
        End If

        tempresult = ""
        If Not IsDBNull(sdr.Item("Arg4")) Then
            tempresult = (sdr.Item("Arg4"))
            If tempresult.Contains(",") Then
                For Each s1 In (Split(tempresult))
                    Arg4.Add(s1)
                Next
            Else
                Arg4.Add(tempresult)
            End If
        End If

        tempresult = ""
        If Not IsDBNull(sdr.Item("Arg5")) Then
            tempresult = (sdr.Item("Arg5"))
            If tempresult.Contains(",") Then
                For Each s1 In (Split(tempresult))
                    Arg5.Add(s1)
                Next
            Else
                Arg5.Add(tempresult)
            End If
        End If

        tempresult = ""
        If Not IsDBNull(sdr.Item("Arg6")) Then
            tempresult = (sdr.Item("Arg6"))
            If tempresult.Contains(",") Then
                For Each s1 In (Split(tempresult))
                    Arg6.Add(s1)
                Next
            Else
                Arg6.Add(tempresult)
            End If
        End If

    End While

    If Not conn.State = ConnectionState.Closed Then
        conn.Close()
    End If

End Sub
End Class

你能帮我把这个更优化吗？

Answer 1

您可以做的一件事就是不要无休止地重复相同的代码：

    tempresult = ""
    If Not IsDBNull(sdr.Item("Arg0")) Then
        tempresult = (sdr.Item("Arg0"))
        If tempresult.Contains(",") Then
            For Each s1 In (Split(tempresult))
                Arg0.Add(s1)
            Next
        Else
            Arg0.Add(tempresult)
        End If
    End If

将其变成这样的函数：

Function SplitResults(ByVal Arg As String) As List(Of String)
    Dim Result As List(Of String) = New List(Of String)()
    If Not IsDbNull(Arg) Then
        If Arg.Contains(",") Then
            Result.AddRange(Split(Arg, ","))
        Else
            Result.Add(Arg)
        End If
    End If
    Return Result
End Function

你会这样称呼：

Arg1 = SplitResults(sdr.Item("Arg1"))

您还可以将单个List(Of String)变量转换为List(Of List(Of String))，这仍然会导致更容易循环或使用LINQ搜索的不规则列表。

VB.NET - Jagged Array，无法弄清楚如何使用它们

1 个答案: