Retrieving values using PreviousPage

Posted on 2008-10-02
Last Modified: 2008-10-24
I am new to asp.Net.  I am attempting to retrieve values from fields on a previous page assign their values to fields on the new page and insert those values into a table.  

When the page loads the previous page values do appear in the correct fields but I keep getting the following error: "Object reference not set to an instance of an object. "

The line of code identified is: Line 133:    Dim myPage As ContentPlaceHolder = PreviousPage.Master.FindControl("ContentPlaceHolder1")

Here is my code:

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Dim body As HtmlGenericControl = Master.FindControl("MasterBody")

        body.Attributes.Add("onkeydown", "HandleRefresh(event,'" & Request.RawUrl & "');")

        Dim myPage As ContentPlaceHolder = PreviousPage.Master.FindControl("ContentPlaceHolder1")

        Dim EmpName As DropDownList = myPage.FindControl("EmpNameCom")

        EN = EmpName.SelectedValue

        Dim RevName As DropDownList = myPage.FindControl("RevNameCom")

        Rev = RevName.SelectedValue

        Dim EmpPos As DropDownList = myPage.FindControl("EmpPosCom")

        Pos = EmpPos.SelectedValue

        Dim State As DropDownList = myPage.FindControl("StateCom")

        St = State.SelectedValue

        Dim SurveyType As DropDownList = myPage.FindControl("SurveyTypeCom")

        SurT = SurveyType.SelectedValue

    End Sub

    Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender

        'sets the FormView in the correct mode depending on the action

        Dim myPage As ContentPlaceHolder = Page.Master.FindControl("ContentPlaceholder1")

        Dim fv As FormView = myPage.FindControl("FormView1")

        If Request.QueryString("mode") = "3" Then


            'If IsPostBack Then

            '    getClaimRepData()

            'End If

        ElseIf Request.QueryString("mode") = "1" Then




            Dim txt As TextBox = fv.FindControl("SurveyDate")

            txt.Text = FormatDateTime(Now(), DateFormat.ShortDate)

            Dim txt1 As TextBox = fv.FindControl("EmpName")

            txt1.Text = EN

            Dim txt2 As TextBox = fv.FindControl("RevName")

            txt2.Text = Rev

            Dim txt3 As TextBox = fv.FindControl("EmpPos")

            txt3.Text = Pos

            Dim txt4 As DropDownList = fv.FindControl("State")

            txt4.SelectedValue = St

            Dim txt5 As TextBox = fv.FindControl("SurveyType")

            txt5.Text = SurT

        End If

    End Sub

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Question by:RedPhoenix3
LVL 18

Accepted Solution

Ajay Sharma earned 500 total points
Comment Utility
instead of using controls use the property to get data.

read this

Author Comment

Comment Utility
Thank you for this suggestion.  I omitted mentioning that I am working on a corporate system where we do not currently have use of Session State in .NET.  While I can see where this solution would work with the use of session state, I need another work around.  Any suggestions?

Thank you!

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