遍历列表

Question

我正试图遍历这个列表，并一次获得一个医生的值。

在excel文档中，每个医生都有多个值，但我希望每次输出一个医生。

在excel文档中，它是HILL CANN HILL，这就是我现在要返回的内容。

但是我想迭代每个医生，所以它会去HILL CANN CANN

        Dim physname As New List(Of String)()

    'Get all of the data from tblPhysician that you will use and put into a list for searching the excel file
    Sql = "select * from tblPhysician "
    conn = New OdbcConnection(connectionString)
    conn.Open()
    comm = New OdbcCommand(Sql, conn)
    dr = comm.ExecuteReader()

    'Populate the physname list with the doctors names
    While (dr.Read())
        physname.Add(dr("PhysicianName").ToString())
    End While

range = oxlsheet.UsedRange
    For rcnt = 1 To range.Rows.Count
        For ccnt = 2 To 6
            varray = CType(range.Cells(rcnt, ccnt), Excel.Range)
            If (IsNumeric(varray.value)) Then
                temp = varray.value.ToString
            Else
                temp = varray.value
            End If

            'Iterate through physname list for each doctor in the list
            For Each doctor As String In physname

                If (rcnt > 8) Then
                    If (IsNumeric(varray.Columns(4).value)) Then
                        temp2 = varray.Columns(4).value.ToString
                    Else
                        temp2 = varray.Columns(4).value
                    End If

                    'If the name in the excel column matches, write out the name and value
                    If (temp2 = doctor) Then
                        Console.WriteLine(varray.Columns(4).value)
                        Console.WriteLine(varray.Columns(5).value)
                        Console.ReadLine()
                    End If


                End If

            Next

        Next
    Next

Answer 1

这里有一些使用LINQ的例子。我强烈建议您阅读它，因为其中有一些强大的东西。学习LINQ以及lambda表达式和匿名方法/函数会非常有帮助！

Imports System
IMports System.Collections.Generic
Imports System.Linq

Public Module Module1

    Public Sub Main()
        Dim physname as new List(Of String) From {"HILL", "CANN", "CANN", "HILL"}

        ' Output the raw list as a baseline...
        Console.WriteLine("Raw list of physicians:")
        For Each physician as string in physname
            Console.WriteLine(physician)
        next

        ' Using Distinct will select each physician once...
        Console.WriteLine()
        Console.WriteLine("Distinct physicians:")
        For Each physician as String in physname.Distinct()
            Console.WriteLine(physician)
        next

        ' Sort the list in place and then display...
        Console.WriteLine()
        Console.WriteLine("Raw physicians list ordered:")
        physname.Sort() 
        For Each physician as String in physname
            Console.WriteLine(physician)
        next
    End Sub
End Module

这个示例并没有以一种复制粘贴到项目中的方式直接解决您的问题，但是它演示了几种遍历泛型列表的方法。