Question

我一直在练习和使用VB.NET和ASP.NET中的代码。我有一个程序，其中有一个GridView名称gvPerson。在GridView中，有一个人员列表及其详细信息，例如姓名，徽章编号，雇用日期等。在GridView顶部，我具有链接按钮控件：添加人员，发布人员设备，编辑人员和删除人员。因此，例如，当我从gridview中选择某人，然后单击“发行人员设备”时，所选人的姓名和ID将出现在出现的模式表单上。现在的问题是，当我运行代码时，出现一个错误，指出我的DataAdapter中没有任何内容。对此我有点陌生，我相信我的逻辑有些偏离，我可能错过了一些东西。这就是我所拥有的：

Dim strSelectedPersonID As String
Dim strSelectedPersonName As String
Dim strSelectPosition As String
Dim strBadgeNo As String

If e.CommandName = "Select" Then
    idx = Convert.ToInt32(e.CommandArgument)

    Dim row As GridViewRow = gvPerson.Rows(idx)

    strSelectedPersonID = row.Cells(1).Text

    Using conn As New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString2").ToString())
        conn.Open()
        Dim dsPerson As New DataSet()
        Dim dr As SqlDataReader
        Dim da As SqlDataAdapter

        Dim strSelectCmd As String = "SELECT * FROM Personnel WHERE SempID = @SempID "
        Dim cmd As New SqlCommand(strSelectCmd, conn)

        cmd.Parameters.AddWithValue("@SempID", strSelectedPersonID)
        cmd.Connection = conn
        da.SelectCommand = cmd
        dr = cmd.ExecuteReader()

        If dr.HasRows Then

            While (dr.Read())
                strSelectPosition = dr(3).ToString
                strBadgeNo = dr(4).ToString
            End While

        End If


        strSelectedPersonName = cmd.ExecuteScalar()
        tbEditPosition.Text = strSelectPosition
        tbEditBadge.Text = strBadgeNo
        conn.Close()

    End Using

End If

tbSecID.Text = strSelectedPersonID
tbSecName.Text = strSelectedPersonName

编辑：这是我使用DataAdapter的代码：

Try
        strconn.Open()

        Dim sQuery As String = "SELECT * FROM tblUsers WHERE Username = @Username AND Password = @Password AND Status= @Status"

        Dim datareader As SqlDataReader
        Dim adapter As New SqlDataAdapter
        Dim parameter As New SqlParameter
        Dim command As SqlCommand = New SqlCommand(sQuery, strconn)

        command.Parameters.AddWithValue("@Username", txtUsername.Text)
        command.Parameters.AddWithValue("@Password", txtPassword.Text)
        command.Parameters.AddWithValue("@Status", 1)

        command.Connection = strconn
        adapter.SelectCommand = command
        datareader = command.ExecuteReader()

        If datareader.HasRows Then

            While (datareader.Read())
                strUserID = datareader(0).ToString
                strUserFname = datareader(3).ToString
                strUserLname = datareader(4).ToString
            End While

            xPersonID = strUserID
            xPersonName = strUserFname + " " + strUserLname

            'MsgBox("Login Successfull!     ", vbInformation, vbOKOnly)

            Response.Redirect("http://localhost:00000/index.aspx")
            datareader.Close()
            LoginOk = True

        Else
            Response.Write("<SCRIPT LANGUAGE=""JavaScript"">  alert('Invalid Username or Password!');</script>")
            ' MsgBox("Invalid Username or Password!    ", vbInformation, vbOKOnly)
            txtUsername.Text = ""
            txtPassword.Text = ""
            txtUsername.Focus()
        End If
        datareader.Close()

    Catch ex As Exception
        'MsgBox(ex.Message)
    End Try

Answer 1

感谢大家的投入。我使用SqlDataReader浏览表并选择用户的详细信息。现在一切似乎都正常。这是我想出的：

    Dim strSelectedPersonID As String
    Dim strSelectedPersonName As String
    Dim strSelectPosition As String
    Dim strBadgeNo As String
    Dim strDateHired As String
    Dim strContactNo As String
    Dim strEmail As String
    Dim strEmerContactNo As String
    Dim strContactPerson As String
    Dim strRemarks As String

    If e.CommandName = "Select" Then
        idx = Convert.ToInt32(e.CommandArgument)

        Dim row As GridViewRow = gvPerson.Rows(idx)

        strSelectedPersonID = row.Cells(1).Text

        Using conn As New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString2").ToString())
            conn.Open()
            Dim dsPerson As New DataSet()
            Dim dr As SqlDataReader

            Dim strSelectCmd As String = "SELECT * FROM Personnel WHERE SempID = @SempID "
            Dim cmd As New SqlCommand(strSelectCmd, conn)

            cmd.Parameters.AddWithValue("@SempID", strSelectedPersonID)
            cmd.Connection = conn
            dr = cmd.ExecuteReader()

            If dr.HasRows Then

                While (dr.Read())
                    strSelectedPersonName = dr(1).ToString
                    strSelectPosition = dr(2).ToString
                    strBadgeNo = dr(3).ToString
                    strDateHired = dr(4).ToString
                    strContactNo = dr(5).ToString
                    strEmail = dr(6).ToString
                    strEmerContactNo = dr(7).ToString
                    strContactPerson = dr(8).ToString
                    strRemarks = dr(10).ToString
                End While

            End If


            'strSelectedPersonName = cmd.ExecuteScalar()
            tbSecName.Text = strSelectedPersonName
            tbEditPosition.Text = strSelectPosition
            tbEditBadge.Text = strBadgeNo
            tbEditHireDate.Text = strDateHired
            tbEditContactNo.Text = strContactNo
            tbEditEmail.Text = strEmail
            tbEmerNo.Text = strEmerContactNo
            tbEditContactPerson.Text = strContactPerson
            tbEditRemarks.Text = strRemarks
            conn.Close()

        End Using

    End If

    tbEditName.Text = strSelectedPersonName
    tbSecID.Text = strSelectedPersonID
    tbSecName.Text = strSelectedPersonName

使用数据阅读器选择和显示数据的问题

1 个答案: