newbie - keeping my object data as page refreshes

Hi all

I have some experience in 'Windows' programming but I am new to Web
programming, I wonder if anyone can help.

I have a middle layer object that brings some data from a database class .
The class reprsents a Callout, has lots of methods and properties and
manages the business logic..

I then have a html page (GUI layer) that creates an instance of a callout,
and from the callout object, it displays some textfields, labour etc plus
some datagrids based on some collections it holds.

Everything works fine until the page refreshes, at which time the object
seems to be destroyed and then recreated.

I want to keep the object alive with its existing data, on the server, and
connect back to it , ie. not create a new object each time. I know I could
use my Callouts WriteDate event to persist the data back to the SQLServer,
and then just re load it, but this isn't what I really want. I would like to
keep the object live until all work has been completed.

I have read a few things about sessions states etc, but don't really know
where to start, and how to make the class persist.

initially I had

public partial class CallOutDetail : System.Web.UI.Page
{
ExistingCallout Currentcallout;
int m_CalloutPK = 0;

protected void Page_Load(object sender, EventArgs e)
{
m_CalloutPK = 1212;
Currentcallout = new ExistingCallout(m_CalloutPK);

I have tried putting the Currentcallout in not postback i.e.

public partial class CallOutDetail : System.Web.UI.Page
{
ExistingCallout Currentcallout;
int m_CalloutPK = 0;

protected void Page_Load(object sender, EventArgs e)
{
m_CalloutPK = 1212;
if (!IsPostBack)
{
// first time
Currentcallout = new ExistingCallout(m_CalloutPK);
SetLabour();
SetMaterials();
}

Any pointers would be welcome

thanks

Andycouple options...
both require that it be serialized

you can place it in the Page's viewstate...

private constant vs_callout="A";

protected CalloutType CurrentCallout{
get{return this.ViewState[vs_callout] as CalloutType;}
set{this.ViewState[vs_callout] = value;}
}

...or place it in the session
}

"AAJ" wrote:

Quote:

Originally Posted by

Hi all
>
I have some experience in 'Windows' programming but I am new to Web
programming, I wonder if anyone can help.
>
I have a middle layer object that brings some data from a database class .
The class reprsents a Callout, has lots of methods and properties and
manages the business logic..
>
I then have a html page (GUI layer) that creates an instance of a callout,
and from the callout object, it displays some textfields, labour etc plus
some datagrids based on some collections it holds.
>
Everything works fine until the page refreshes, at which time the object
seems to be destroyed and then recreated.
>
I want to keep the object alive with its existing data, on the server, and
connect back to it , ie. not create a new object each time. I know I could
use my Callouts WriteDate event to persist the data back to the SQLServer,
and then just re load it, but this isn't what I really want. I would like to
keep the object live until all work has been completed.
>
I have read a few things about sessions states etc, but don't really know
where to start, and how to make the class persist.
>
initially I had
>
public partial class CallOutDetail : System.Web.UI.Page
{
ExistingCallout Currentcallout;
int m_CalloutPK = 0;
>
protected void Page_Load(object sender, EventArgs e)
{
m_CalloutPK = 1212;
Currentcallout = new ExistingCallout(m_CalloutPK);
>
>
I have tried putting the Currentcallout in not postback i.e.
>
public partial class CallOutDetail : System.Web.UI.Page
{
ExistingCallout Currentcallout;
int m_CalloutPK = 0;
>
protected void Page_Load(object sender, EventArgs e)
{
m_CalloutPK = 1212;
if (!IsPostBack)
{
// first time
Currentcallout = new ExistingCallout(m_CalloutPK);
SetLabour();
SetMaterials();
}
>
>
Any pointers would be welcome
>
thanks
>
Andy
>
>
>

thanks David

"David Jessee" <DavidJessee@.discussions.microsoft.comwrote in message
news:CF0F5237-8616-4C4B-9DA9-252BA0946C1D@.microsoft.com...

Quote:

Originally Posted by

couple options...
both require that it be serialized
>
you can place it in the Page's viewstate...
>
private constant vs_callout="A";
>
protected CalloutType CurrentCallout{
get{return this.ViewState[vs_callout] as CalloutType;}
set{this.ViewState[vs_callout] = value;}
}
>
...or place it in the session
}
>
>
>
"AAJ" wrote:
>

Quote:

Originally Posted by

>Hi all
>>
>I have some experience in 'Windows' programming but I am new to Web
>programming, I wonder if anyone can help.
>>
>I have a middle layer object that brings some data from a database class
>.
>The class reprsents a Callout, has lots of methods and properties and
>manages the business logic..
>>
>I then have a html page (GUI layer) that creates an instance of a
>callout,
>and from the callout object, it displays some textfields, labour etc plus
>some datagrids based on some collections it holds.
>>
>Everything works fine until the page refreshes, at which time the object
>seems to be destroyed and then recreated.
>>
>I want to keep the object alive with its existing data, on the server,
>and
>connect back to it , ie. not create a new object each time. I know I
>could
>use my Callouts WriteDate event to persist the data back to the
>SQLServer,
>and then just re load it, but this isn't what I really want. I would like
>to
>keep the object live until all work has been completed.
>>
>I have read a few things about sessions states etc, but don't really know
>where to start, and how to make the class persist.
>>
>initially I had
>>
>public partial class CallOutDetail : System.Web.UI.Page
>{
>ExistingCallout Currentcallout;
>int m_CalloutPK = 0;
>>
>protected void Page_Load(object sender, EventArgs e)
>{
>m_CalloutPK = 1212;
>Currentcallout = new ExistingCallout(m_CalloutPK);
>>
>>
>I have tried putting the Currentcallout in not postback i.e.
>>
>public partial class CallOutDetail : System.Web.UI.Page
>{
>ExistingCallout Currentcallout;
>int m_CalloutPK = 0;
>>
>protected void Page_Load(object sender, EventArgs e)
>{
>m_CalloutPK = 1212;
>if (!IsPostBack)
>{
>// first time
>Currentcallout = new ExistingCallout(m_CalloutPK);
>SetLabour();
>SetMaterials();
>}
>>
>>
>Any pointers would be welcome
>>
>thanks
>>
>Andy
>>
>>
>>

NEWBIE - Working with Data in ASP.NET 2.0 :: Creating a Data Access Layer (Sample)

Hi all,

I am really new to ASP.net, so thought I would go through one of the samples on here.

I have started the Working with Data in ASP.NET 2.0 :: Creating a Data Access Layer sample, but I get stuck when i add the code to AllProducts.aspx.cs for some reason, I can add the directive 'using NorthwindTableAdapters' when I compile after adding this directive, I get an error ...

Error 143 The type or namespace name 'NorthWindTableAdapters' could not be found (are you missing a using directive or an assembly reference?) C:\data\tutorial\Default.aspx.cs 10 7 C:\data\tutorial\

Any ideas why I am getting this?

Thanks

Pete

Did u added the northwind database to app_data folder?

you need to add that at first.

Hi Crige,

I added the connection to data connections in the Solution explorer, and also added a dataset item to the project as per the tutorial.

How do I add the database to the app_data_folder, when I right click on app_data I get an add new option dialogue, when I look at the database icon in this dialogue, it shows 'empty database' the database I am using is an existing database on the server...

Pete

I am having the same problem. I'm using SQL 2000 instead of the App_Data approach. The document explains how to use this approach but does not explain that the Northwind database is REQUIRED to be in the App_Data folder. Are you sure that this is required? If not, then what else could be the problem?

Thanks,

Larry
You're not going to believe this...

The class name is case-sensitive... NorthwindTableAdapters must be entered as NorthWindTableAdapters (with a capital W). I noticed this by adding an ObjectDataSource to AllProducts.aspx and then selecting a business object in the 'configure data source' screen. The class name is displayed with a capital W.

At least this gets me past this error message... hope it does the same for you.

Thanks,

Larry
Apparently, I named my DataSet NorthWind, with a capital W. My previous post will only resolve the problem if you did the same...

Note that the tutorial did NOT use a capital W, so I introduced this 'bug' myself by naming the xsd file wrong.

At any rate, it's fixed now so it's time to move on.