Arrays 使用streamreader将文件加载到数组中

Arrays 使用streamreader将文件加载到数组中,arrays,vb.net,streamreader,Arrays,Vb.net,Streamreader,我试图获取一个文件,并使用StreamReader对其进行迭代,然后将每一行加载到一个数组中。我知道该文件输入正确,它是一个文本文件,数据以行形式输入 Dim req As WebRequest = WebRequest.Create("http://www.blahahahaha.com/data/myfile.csv") Dim res As WebResponse = req.GetResponse() Dim stream As Stream = res.GetR

我试图获取一个文件,并使用StreamReader对其进行迭代,然后将每一行加载到一个数组中。我知道该文件输入正确,它是一个文本文件,数据以行形式输入

    Dim req As WebRequest = WebRequest.Create("http://www.blahahahaha.com/data/myfile.csv")
    Dim res As WebResponse = req.GetResponse()
    Dim stream As Stream = res.GetResponseStream()

    Dim lines2 As String()
    Using r As StreamReader = New StreamReader(stream, Encoding.ASCII)
        Dim line As String
        line = r.ReadLine
        Do While (Not line Is Nothing)
            lines2(lineCount2) = r.ReadLine
            lineCount2 += 1
        Loop
    End Using

但生成的数组是空的。我做错了什么以及如何修复它?

这将以字符串数组的形式返回6行,第一行是列名

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim csvAddress As String =
        "https://download.microsoft.com/download/4/C/8/4C830C0C-101F-4BF2-8FCB-32D9A8BA906A/Import_User_Sample_en.csv"

    Dim Lines As String() = GetCsvData(csvAddress)
    For Each line As String In Lines
        Console.WriteLine(line)
    Next
End Sub
Public Function GetCsvData(ByVal csvAddress As String) As String()
    Dim request As WebRequest = WebRequest.Create(csvAddress)
    request.Credentials = CredentialCache.DefaultCredentials
    Dim response As WebResponse = request.GetResponse()

    Dim dataStream As Stream = response.GetResponseStream()
    Dim LineList As New List(Of String)

    Using r As StreamReader = New StreamReader(dataStream, Encoding.ASCII)
        Dim currentLine As String = r.ReadLine
        Do While (Not String.IsNullOrWhiteSpace(currentLine))
            LineList.Add(currentLine)
            currentLine = r.ReadLine
        Loop
    End Using

    Return LineList.ToArray

End Function
这一行:

Dim lines2 As String()
只声明
lines2
将是一个字符串数组。阵列本身未初始化:

Dim lines2(9) As String     ' THIS one has elements
但由于您可能不知道将有多少行,请使用列表:

Dim Lines As New List(Of String)

Using r As StreamReader = New StreamReader(Stream, Encoding.ASCII)
    Dim line As String
    line = r.ReadLine
    Do Until String.IsNullOrEmpty(line)
        Lines.Add(line)
        line = r.ReadLine
    Loop
End Using
如果调用代码确实需要数组:

Return Lines.ToArray()

您从不初始化数组。将其更改为一个列表(字符串),因为您不知道将有多少行。我认为这会引发一个例外。我将Nothing测试更改为
String.IsNullOrEmpty()
Too您可以在代码中显示它吗?