VB：在尝试将 csv 读入数据网格时索引数组边界之外答案

【问题标题】：VB: Index outside bounds of array while trying to read csv into a datagridVB：在尝试将 csv 读入数据网格时索引数组边界之外
【发布时间】：2019-01-14 11:24:35
【问题描述】：

我正在尝试从 csv 文件在数据网格上打印，但在 PhNumber 列上出现“System.IndexOutOfRangeException: 'Index was outside the bounds of the array.'”错误。当我删除此列时，错误将移至“年龄”列。我在这里到底做错了什么？我认为这是我编写 csv 的方式有误，但我检查了一千次，我找不到任何东西。

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Public Class Form1
Dim TutorTable As New DataTable
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    With TutorTable
        .Columns.Add("Name", System.Type.GetType("System.String"))
        .Columns.Add("Age", System.Type.GetType("System.String"))
        .Columns.Add("Subjects", System.Type.GetType("System.String"))
        .Columns.Add("ATAR", System.Type.GetType("System.String"))
        .Columns.Add("Location", System.Type.GetType("System.String"))
        .Columns.Add("PhNumber", System.Type.GetType("System.String"))
    End With
End Sub


Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim Reader As New IO.StreamReader("D:\Users\user\Downloads\TutorData.csv", System.Text.Encoding.Default)
    Dim StringLine As String = ""
    Do
        StringLine = Reader.ReadLine
        If StringLine Is Nothing Then Exit Do
        Dim Columns() As String = StringLine.Split(",")
        Dim NewRow As DataRow = TutorTable.NewRow
        NewRow("Name") = Columns(0)
        NewRow("Age") = Columns(1)
        NewRow("Subjects") = Columns(2)
        NewRow("ATAR") = Columns(3)
        NewRow("Location") = Columns(4)
        NewRow("PhNumber") = Columns(5)
        TutorTable.Rows.Add(NewRow)
    Loop
    Reader.Close()

    DataGridView1.DataSource = TutorTable
    Me.Text = TutorTable.Rows.Count & "rows"
End Sub

【问题讨论】：

你试过调试你的程序吗？专栏的内容是什么？在Dim NewRow As DataRow = TutorTable.NewRow 行设置断点并告诉我们。
您提供的代码示例和数据对我来说绝对没问题。
您确定您的所有数据都没有缺少逗号吗？
BTW 提出了一个结构良好的问题，因此我们可以尝试重现正在发生的事情。
当您的代码挂起时，将鼠标悬停在 Dim Columns() As String = StringLine.Split(",") 行中的 Columns 数组上，以查看数组中有多少元素。

标签： arrays vb.net csv

【解决方案1】：

在 .Split 之后立即检查 Columns 的长度。分支到一个函数来修复数据。

Private Sub OPCode()
        Dim Columns() As String = StringLine.Split(",")
        If Columns.Length < 6 Then
            ReDim Preserve Columns(5)
            Columns = FixMissingData(Columns)
        End If
        Dim NewRow As DataRow = TutorTable.NewRow
        'and the rest of your code
End Sub
Private Function FixMissingData(arrColumns As String()) As String()
        'Code to parse fields, probably using RegEx
        'reassign values to correct Columns index, fill empty data columns with and empty string or default value
        'such as "missing data"
        Return arrColumns
End Function

【讨论】：