Question

我试图从txt文件中读取，然后在相应的文本框中显示文件的内容，这些字段用逗号分隔。但是，它只是读取文件的第一行，我不知道如何纠正这一点。这是我的vb.net代码：

FileOpen(1, "MembersArea.txt", OpenMode.Input) 'OPEN FILE FOR READING'
    Dim crosscheck As String
    Dim flag As Boolean
    crosscheck = Val(txtCrosscheck.Text)
    flag = False
    While Not EOF(1) 'OPEN FILE AT BEGINNING'
        Input(1, Member_ID) 'READ LINE
        Input(1, Forename)
        Input(1, Surname)
        Input(1, Addressline1)
        Input(1, Addressline2)
        Input(1, Town)
        Input(1, County)
        Input(1, Postcode)
        If Member_ID = crosscheck Then
            flag = True
        Else
        End If
        Exit While
    End While
    If flag = True Then
        txtCrosscheck.Enabled = False
        btncrosscheck.Enabled = False
        btnaddlog.Enabled = True
        cmbevent.Enabled = True
        dtpevent.Enabled = True
        txtheartratebefore.Enabled = True
        txtheartrateafter.Enabled = True
        cmbevent.Focus()
    Else
        MsgBox("Member ID does not exist. Please enter an existing Member ID to add Training Log")
    End If

    nameconcat = Forename & " " & Surname


    FileClose(1)

谢谢你！

Answer 1

我不明白你的问题。我想我明白文件的第一行包含由＆＃34;，＆＃34;分隔的各种信息。像这样：＆＃34;一，二，三，四，五＆＃34;并且您想要提取这些字段并将它们放在单独的文本框中。将这些字段分开是足够的拆分命令

        Dim riga As String = "one,two,three,four,five"
        Dim fields() As String = riga.Split(",")

现在：

   fields(0)="one"
   fields(1)="two"
   fields(2)="three"
   fields(3)="four"
   fields(4)="five"

这样：

   textbox1.text=fields(0)
   etc.

Answer 2

正如John Koerner所写，你正在调用Exit While，它将在第一次迭代后退出。

另外，在VB.NET中，我认为最好为此目的使用streamreader。 编辑：注意，您需要为System.IO添加导入才能使用streamreader。

您可以在代码顶部使用此行添加该导入：

Imports System.IO

我在编写和阅读CSV方面没有太多经验，所以我创建了一个函数来读取直到下一个逗号。使用Private声明一个streamreader。

Private streamMembersArea As StreamReader

    Private Function ReadInfo()
    Dim strField As String = ""
    Do
        strField += streamMembersArea.Read()

    Loop Until strField.Contains(",")
    strField = strField.Remove(strField.Length - 1, 1)
    Return strField
End Function

这实际上应该不需要你打电话给Not EOF，但是如果你不确定所有字段都会输入到文件中，我建议你检查它......

你可以通过致电：

来做到这一点

While streamMembersArea.Peek <> -1 'Checks whether there is another character available, if not (like at the end of a file), it returns -1
... ' Place the following code here
...
End While

您可以通过以下方式执行此操作：

'Declare variables
    Dim crosscheck As String
    Dim flag As Boolean
    'Removed Dim for streamReader, now a private, above

    'crosscheck 
    crosscheck = Val(txtCrosscheck.Text)

    'flag
    flag = False

    'Open file for input
    streamMembersArea = IO.File.OpenText("MembersArea.txt")

    'Read info into variables
    Member_ID = ReadInfo()
    Forename = ReadInfo()
    Surname = ReadInfo()
    Addressline1 = ReadInfo()
    Addressline2 = ReadInfo()
    Town = ReadInfo()
    County = ReadInfo()
    Postcode = ReadInfo()

    'Close stream
    streamMembersArea.Close() ' Closes the file, make sure you include this.

    'Validate Member ID
    If Member_ID = crosscheck Then
        flag = True
    Else ' Not needed, but fine either way
    End If
    'Exit While <- Commented out, no more 'While' loop, unnecessary now
    'End While <- Not used anymore either

    If flag = True Then
        txtCrosscheck.Enabled = False
        btncrosscheck.Enabled = False
        btnaddlog.Enabled = True
        cmbevent.Enabled = True
        dtpevent.Enabled = True
        txtheartratebefore.Enabled = True
        txtheartrateafter.Enabled = True
        cmbevent.Focus()
    Else
        MsgBox("Member ID does not exist. Please enter an existing Member ID to add Training Log")
    End If

    nameconcat = Forename & " " & Surname


    'FileClose(1) <- No longer needed, closed stream earlier

如果您需要任何其他帮助，请与我们联系。

只读取文件的第一行

2 个答案: