frm_changeadmpass.vb

是关于图书管理系统的用vb.net 和access开发的

Imports System.Data.OleDb
Public Class frm_ChangeAdmPass

    Dim myConnection As New OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; Data source=D:\library.mdb")
    Dim myCommand As OleDbCommand
    Dim myReader As OleDbDataReader

    Private Sub frm_ChangeAdmPass_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        admNotxt.Focus()
    End Sub

   
    Private Sub oldpasstxt_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles oldPasstxt.KeyPress
        If e.KeyChar = ChrW(System.Windows.Forms.Keys.Enter) Then

            checkValidAdm()
        End If
    End Sub
    Sub checkValidAdm()

        Dim admNo As String = ""
        Dim password As String = ""


        myConnection.Open()
        myCommand = New OleDbCommand("select * from Administrator where AdmNo = '" & admNotxt.Text & _
           "'", myConnection)
        myReader = myCommand.ExecuteReader()

        While myReader.Read
            admNo = myReader("AdmNo")
            password = myReader("Password")
        End While

        myConnection.Close()
        myReader.Close()
        myCommand.Dispose()

        If admNo = "" Then
            MsgBox("Invalid Administrator ID!")
            admNotxt.Clear()
            oldPasstxt.Clear()
            admNotxt.Focus()

        Else

            If password = oldPasstxt.Text Then
                newPasstxt.Focus()
            Else

                MsgBox("Invalid Administrator Password!")
                oldPasstxt.Focus()
                oldPasstxt.SelectAll()


            End If
        End If
    End Sub


    Private Sub newpasstxt_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles newPasstxt.KeyPress
        If e.KeyChar = ChrW(System.Windows.Forms.Keys.Enter) Then
            If newPasstxt.Text = "" Then
                MsgBox("password can not be empty!")
                newPasstxt.Focus()
            Else
                againtxt.Focus()

            End If
        End If
    End Sub



    Private Sub okbt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles okbt.Click
        If checkPasswordSame() Then
            changePassword()
        Else
            MsgBox("The 2nd input new password is not as same as the 1st one!")
            againtxt.Focus()
            againtxt.SelectAll()
        End If

    End Sub

    Function checkPasswordSame() As Boolean
        Dim firstStr As String = newPasstxt.Text
        Dim secondStr As String = againtxt.Text

        If firstStr.Equals(secondStr) Then
            Return True
        Else
            Return False
        End If
    End Function
    Sub changePassword()

        myConnection.Open()
        myCommand = New OleDbCommand("Update Administrator set [Password]='" & newPasstxt.Text & _
        "' where admNo='" & admNotxt.Text & "'", myConnection)


        myCommand.ExecuteNonQuery()
        MsgBox("Change password success!")



        myConnection.Close()
        myCommand.Dispose()
    End Sub

    Private Sub exitbt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles exitbt.Click
        Me.Close()

    End Sub

    Private Sub resetbt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles resetbt.Click
        admNotxt.Clear()
        oldPasstxt.Clear()
        newPasstxt.Clear()
        againtxt.Clear()

    End Sub
End Class