ASP.NET

Re: How can I solve "Object Referance not set to an instance of an object" error problem?

6-Oct-08 4:47

Hi Jaffer,

The problem is dropdownboxes are not bind to any dataobjects. I was aimed to populate these boxes in runtime. However if I bind them to an objectdatasource, I am not able to define an event eg. (Dropdownbox_Clicked) because they are inside of th Formview control.

Therefore, I decided not to bind them and I don't use formview now. However now I am facing to another issue, How I am giong to assign their values as inputparameter to objectdatasource insert event below.

Here is the code sample. All I need to pass 5 doprdownboxes selectedvalue arguments to below procedure as inputparameters. When I click a button, these paramaters must be carried to following procedure.

<br />
    Private Sub ObjectDataSource1_Inserting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ObjectDataSourceMethodEventArgs) Handles ObjectDataSource1.Inserting<br />
<br />
        Dim ParamsFromPage As IDictionary = e.InputParameters<br />
<br />
        Dim NewObj As New property_availability(0, 0, 0, 0, "")<br />
<br />
        NewObj.Getyear = Int32.Parse(ParamsFromPage("GetYear")).ToString<br />
        NewObj.GetMonth = Int32.Parse(ParamsFromPage("GetMonth")).ToString<br />
        NewObj.GetDayFrom = Int32.Parse(ParamsFromPage("GetDayFrom")).ToString<br />
        NewObj.GetDayTo = Int32.Parse(ParamsFromPage("GetDayTo")).ToString<br />
        NewObj.GetStatus = ParamsFromPage("GetStatus").ToString<br />
<br />
        ParamsFromPage.Clear()<br />
<br />
        ParamsFromPage.Add("GetYear", NewObj.Getyear)<br />
        ParamsFromPage.Add("GetMonth", NewObj.GetMonth)<br />
        ParamsFromPage.Add("GetDayFrom", NewObj.GetDayFrom)<br />
        ParamsFromPage.Add("GetDayTo", NewObj.GetDayTo)<br />
        ParamsFromPage.Add("GetStatus", NewObj.GetStatus)<br />
<br />
    End Sub<br />
<br />

What a curious mind needs to discover knowledge is noting else than a pin-hole.

AlexeiXX36-Oct-08 5:03

AlexeiXX3

6-Oct-08 5:03

Instead of using the object datasource to insert, why dont you call your busines object's insert method directly??

Alexei Rodriguez

Re: How can I solve "Object Referance not set to an instance of an object" error problem?

JUNEYT6-Oct-08 5:28

Re: How can I solve "Object Referance not set to an instance of an object" error problem?

6-Oct-08 5:28

I use Business object's insert method actually. Please see the code below. However I decided not use Formview because in runtime I must control dropdownboxes and their events. Now I am not able to pass the values of these boxes to below procedure because this boxes are not bind to objectdatasource anymore. I have to externally bind them somehow but I don't knwo how to do that.

<br />
    Private Sub ObjectDataSource1_Inserting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ObjectDataSourceMethodEventArgs) Handles ObjectDataSource1.Inserting<br />
<br />
        Dim ParamsFromPage As IDictionary = e.InputParameters<br />
<br />
        Dim NewObj As New property_availability(0, 0, 0, 0, "")<br />
<br />
        NewObj.Getyear = Int32.Parse(ParamsFromPage("GetYear")).ToString<br />
        NewObj.GetMonth = Int32.Parse(ParamsFromPage("GetMonth")).ToString<br />
        NewObj.GetDayFrom = Int32.Parse(ParamsFromPage("GetDayFrom")).ToString<br />
        NewObj.GetDayTo = Int32.Parse(ParamsFromPage("GetDayTo")).ToString<br />
        NewObj.GetStatus = ParamsFromPage("GetStatus").ToString<br />
<br />
        ParamsFromPage.Clear()<br />
<br />
        ParamsFromPage.Add("GetYear", NewObj.Getyear)<br />
        ParamsFromPage.Add("GetMonth", NewObj.GetMonth)<br />
        ParamsFromPage.Add("GetDayFrom", NewObj.GetDayFrom)<br />
        ParamsFromPage.Add("GetDayTo", NewObj.GetDayTo)<br />
        ParamsFromPage.Add("GetStatus", NewObj.GetStatus)<br />
<br />
    End Sub<br />
<br />
<br />

What a curious mind needs to discover knowledge is noting else than a pin-hole.

AlexeiXX36-Oct-08 8:50

AlexeiXX3

6-Oct-08 8:50

Unless im missing something, i dont see any sense on this previous code

You read the values from e.insertparameters into ParamsFromPage
Yo add ParamsFromPage into a temp object
You clear ParamsFromPage
You add them back to ParamsFromPage

???
What are you doing?

Alexei Rodriguez

Re: How can I solve "Object Referance not set to an instance of an object" error problem?

JUNEYT6-Oct-08 9:05

Re: How can I solve "Object Referance not set to an instance of an object" error problem?

6-Oct-08 9:05

Actually I have paased this paramaters to a class object if you carefully examine the code and then I pass the paramaters to insert function of objectdatasource object. In back and there is a kist object what keep the all the values.

Thanks Alex.

What a curious mind needs to discover knowledge is noting else than a pin-hole.

AlexeiXX36-Oct-08 9:15

AlexeiXX3

6-Oct-08 9:15

NewObj.Getyear = Int32.Parse(ParamsFromPage("GetYear")).ToString
NewObj.GetMonth = Int32.Parse(ParamsFromPage("GetMonth")).ToString
NewObj.GetDayFrom = Int32.Parse(ParamsFromPage("GetDayFrom")).ToString
NewObj.GetDayTo = Int32.Parse(ParamsFromPage("GetDayTo")).ToString
NewObj.GetStatus = ParamsFromPage("GetStatus").ToString

ParamsFromPage.Clear()

ParamsFromPage.Add("GetYear", NewObj.Getyear)
ParamsFromPage.Add("GetMonth", NewObj.GetMonth)
ParamsFromPage.Add("GetDayFrom", NewObj.GetDayFrom)
ParamsFromPage.Add("GetDayTo", NewObj.GetDayTo)
ParamsFromPage.Add("GetStatus", NewObj.GetStatus)

What are you doing here??
paramsFromPage has the same values that i had in the beggining

By the way...
If carefully look at this:
NewObj.GetDayTo = Int32.Parse(ParamsFromPage("GetDayTo")).ToString
I think that getDayTo expects an int32, you are making extra conversions, you case the value to int32 and then to string with the tostring method and then the result is casted back to int32 when you assign it

Alexei Rodriguez

Re: How can I solve "Object Referance not set to an instance of an object" error problem?

JUNEYT6-Oct-08 11:15

Re: How can I solve "Object Referance not set to an instance of an object" error problem?

6-Oct-08 11:15

You are right Alex. I forgot to take it out actually. Thanks Smile | :)

What a curious mind needs to discover knowledge is noting else than a pin-hole.

ToddHileHoffer6-Oct-08 3:01

ToddHileHoffer

6-Oct-08 3:01

Well, if you are 100% sure the name is correct (including the case) try executing the code at a later stage in the page's life cycle. Perhaps the control will not be null in page_preRender event.

I didn't get any requirements for the signature

Does .Net Framwork needed?

Pedram Behroozi6-Oct-08 0:13

6-Oct-08 0:13

Hello,
I'm newbie in ASP.NET and I want to develop a website using it but does my visitors need to install .Net Framework to visit my website? Confused | :confused:

Thanks

While (true) { Human.isLearnable = true; }

J4amieC6-Oct-08 0:14

J4amieC

6-Oct-08 0:14

No, they just need a web browser, however the .NET framework is of course required on the server.

Pedram Behroozi6-Oct-08 0:18

6-Oct-08 0:18

Oh, I feel better now Smile | :)

Thanks

While (true) { Human.isLearnable = true; }

Re: Good Tutorial

eyeseetee6-Oct-08 0:21

eyeseetee

6-Oct-08 0:21

Check this out

http://quickstarts.asp.net/QuickStartv20/aspnet/

Deliver yesterday, code today, think tomorrow.
"http://www.heuse.com/cphumor.htm"

bagla6-Oct-08 2:09

bagla

6-Oct-08 2:09

its necessary to install .net frame work

N a v a n e e t h6-Oct-08 2:28

N a v a n e e t h

6-Oct-08 2:28

bagla wrote:
its necessary to install .net frame work

WOW !

Navaneeth

How to use google | Ask smart questions

Pedram Behroozi6-Oct-08 2:58

6-Oct-08 2:58

Really?

You mean in Server-Side? Or in Client-Side?
I understood that .Net Framework should install in Server and I know why, but in Client?
Joking me, Right? Laugh | :laugh:

While (true) { Human.isLearnable = true; }

J4amieC6-Oct-08 4:20

J4amieC

6-Oct-08 4:20

ignore the clueless answer you got here. I assure you that only the server requires the framework.

Pedram Behroozi6-Oct-08 4:31

6-Oct-08 4:31

:-bd

While (true) { Human.isLearnable = true; }

What about other OSs?

Pedram Behroozi6-Oct-08 8:54

Re: What about other OSs?

6-Oct-08 8:54

What about Linux (or any other OSs) users? Can they visit my website?

While (true) { Human.isLearnable = true; }

Adam Maras6-Oct-08 9:19

Adam Maras

6-Oct-08 9:19

Anybody with a working web browser can visit your website.

Re: What about other OSs?

Pedram Behroozi6-Oct-08 10:17