Question

我无法在visual basic 2012中创建我的记录编号，我到目前为止的代码是覆盖以前保存的文件吗？

我的模块

Imports System.IO
Module AssModule
    Structure employee
        ' Public Name As String
        ' Public ID As String

        <VBFixedString(30)> Dim name As String ' vb fixed string
        <VBFixedString(5)> Dim id As String ' vb fixed string



    End Structure

    Structure transaction
        <VBFixedString(5)> Dim id As String ' vb fixed string
        Dim time As Date
        <VBFixedString(3)> Dim type As String ' vb fixed string
    End Structure

    ' Public fileSize As Integer = Len(index)
    ' Public Staff(100) As employee ' staff as new name for eployeee structure


    Public myEmployee As employee

    Public r As Integer = 5
    Public fileNumber As Integer = FreeFile()
    Public mySizerecordnumber As Integer = Len(myEmployee)
    Public recordNumber As Integer



    Public index As Byte



    Public Sub setRecordNumber()
        Dim n As Byte = 0
        FileOpen(fileNumber, "binData.dat", OpenMode.Random, OpenAccess.Read)
        While Not EOF(fileNumber)
            n = n + 1
            FileGet(fileNumber, myEmployee, n)
        End While
        recordNumber = n
        FileClose(fileNumber)
    End Sub



End Module

添加员工按钮

Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
    For n = 0 To 3
        FileOpen(fileNumber, "binData.dat", OpenMode.Random, OpenAccess.Write, , mySizerecordnumber)
        myEmployee.id = txtID.Text
        myEmployee.name = txtName.Text
        recordNumber = recordNumber + 1
        FilePut(fileNumber, myEmployee, recordNumber)
        FileClose(fileNumber)
    Next
    Me.Close()
End Sub

Answer 1

好的，让我们分解你的btnSave_Click功能。

对于0到3，每次，你：打开文件，读取文件，将结果放入myEmployee，然后将其放回文件中并关闭。

您想要做的（我认为）是将新员工保存在文件末尾

您应该打开文件，移到最后，然后保存新记录：

Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
    setRecordNumber()
    FileOpen(fileNumber, "binData.dat", OpenMode.Random, OpenAccess.Write, , mySizerecordnumber)
    myEmployee.id = txtID.Text
    myEmployee.name = txtName.Text
    FilePut(fileNumber, myEmployee, recordNumber)
    FileClose(fileNumber)
    Me.Close()
End Sub

随机访问文件visual basic 2012

1 个答案: