Solved

Retrieving values using PreviousPage

Posted on 2008-10-02
2
468 Views
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
            Me.FormView1.ChangeMode(FormViewMode.Edit)
            'If IsPostBack Then
            '    getClaimRepData()
            'End If
        ElseIf Request.QueryString("mode") = "1" Then
            Me.FormView1.ChangeMode(FormViewMode.ReadOnly)
        Else
            Me.FormView1.ChangeMode(FormViewMode.Insert)
            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

Open in new window

0
Comment
Question by:RedPhoenix3
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 18

Accepted Solution

by:
Ajay Sharma earned 500 total points
ID: 22632427
instead of using controls use the property to get data.

read this

http://msdn.microsoft.com/en-us/library/6c3yckfw.aspx

http://steveorr.net/faq/PassValues.aspx
0
 

Author Comment

by:RedPhoenix3
ID: 22654301
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!
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I recently went through the process of creating a Calendar Control of events with the basis of using a database to keep track of the dates that are selectable, one requirement was to have the selected date pop-up in a simple lightbox.  At first this…
In .NET 2.0, Microsoft introduced the Web Site.  This was the default way to create a web Project in Visual Studio 2005.  In Visual Studio 2008, the Web Application has been restored as the default web Project in Visual Studio/.NET 3.x The Web Si…
In this video, viewers are given an introduction to using the Windows 10 Snipping Tool, how to quickly locate it when it's needed and also how make it always available with a single click of a mouse button, by pinning it to the Desktop Task Bar. Int…
Add bar graphs to Access queries using Unicode block characters. Graphs appear on every record in the color you want. Give life to numbers. Hopes this gives you ideas on visualizing your data in new ways ~ Create a calculated field in a query: …

615 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question