Arrays 使用streamreader将文件加载到数组中
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
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?