Question

我只需要一点帮助，我已经有一个登录，但我只是想创建一个提示，如果我输入错误的用户名和正确的密码，对话框显示只有用户名不正确，如果老虎钳反之，对话框显示密码不正确。如果用户名和密码都不正确，对话框显示用户名和密码不正确。它在MS ACCESS中连接，这是我的代码：

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim connection As New OleDbConnection

    connection = New OleDb.OleDbConnection
    connection.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;; Data Source=" & Application.StartupPath & "\Data.mdb"

    Dim cmd As OleDbCommand = New OleDbCommand("SELECT User,Password FROM tblUser where User=? and Password=?", connection)

    cmd.Parameters.AddWithValue("User", Me.TextBox1.Text)
    cmd.Parameters.AddWithValue("Password", Me.TextBox2.Text)

    Try
        connection.Open()
        Dim read As OleDbDataReader = cmd.ExecuteReader()

        If read.HasRows Then
            read.Read()

            If Me.TextBox1.Text.ToLower() = read.Item("user").ToString And Me.TextBox2.Text.ToLower = read.Item("Password").ToString Then
                MsgBox("Login successful")
                Me.Hide()
                Form2.Show()

            End If

        Else
            MsgBox("Login unsuccessful,no connection", MsgBoxStyle.OkOnly, "Invalid")
        End If

        read.Close()
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    Finally
        connection.Close()
    End Try

End Sub

Answer 1

试试这个：

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim connection As New OleDbConnection

    connection = New OleDb.OleDbConnection
    connection.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;; Data Source=" & Application.StartupPath & "\Data.mdb"

    Dim cmd As OleDbCommand = New OleDbCommand("SELECT User,Password FROM tblUser where User=?", connection)

    cmd.Parameters.AddWithValue("User", Me.TextBox1.Text)

    Try
        connection.Open()
        Dim read As OleDbDataReader = cmd.ExecuteReader()

        If read.HasRows Then
            read.Read()

            If Me.TextBox2.Text.ToLower = read.Item("Password").ToString Then
                MsgBox("Login successful")
                Me.Hide()
                Form2.Show()
            Else
                MsgBox("Login unsuccessful, Incorrect Password", MsgBoxStyle.OkOnly, "Invalid")
            End If

        Else
            MsgBox("Login unsuccessful, Invalid UserName", MsgBoxStyle.OkOnly, "Invalid")
        End If
        read.Close()
    Catch ex As OleDbException
        MsgBox("Login unsuccessful,no connection", MsgBoxStyle.OkOnly, "Invalid")
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    Finally
        connection.Close()
    End Try

End Sub

VB 2008使用MS ACCESS登录用户名和密码

1 个答案: