Passing Values

Colonel Angus · August 12th, 2004, 10:52 AM

I can't believe I'm asking this, but...

Up until this point in my ASP.NET travels, I have only had to pass simple values from one page to another. Most of the time I have used the querystring to pass an ID value - rarely, I use a Session variable.

Before .NET, I would pass the values via form variables; hidden inputs and the like.

How do I accomplish this function without resorting to using the Session?

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In God we trust, everything else we test.

katsarosj · August 12th, 2004, 11:29 AM

If you are transferring to a different page, how about using "Server.Transfer("page_to_go_to.aspx", True)"?

I believe you can access the original's form data by setting the second argument(preserveForm) to true.

I believe you will have to also set the EnableViewStateMac attribute of the Page directive to false on the destination page. Otherwise, it will think that the ViewState of the new page has been tampered with.

J

planoie · August 12th, 2004, 01:22 PM

Colonel,

You can pass additional values on the querystring after the first with the &...

.aspx?id=1234&another=3423&yetanother=hello

They'll all end up in the Request.QueryString collection.

If you need the values to be hidden, I'd recommend the session. Because you can't (yet) have a form post to another page, it's not very easy to deal with hidden form values and the like. Plus, you then have to deal with manual extraction of the values from the Request.Form collection, and because of .NET's naming methods, the form element names could change.

Colonel Angus · August 13th, 2004, 07:24 AM

Yeah, I'm familiar with appending querystring values with &, but I need to avoid it in this case. In general, I like to keep the querystring pretty clean if I can.

Well it appears my best option is to set Session variables, use them and then remove them.

Thanks for your comments as always!

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In God we trust, everything else we test.

Hal Levy · August 13th, 2004, 09:14 AM

Is there a reason you are avoiding the session in this case? .NET sessions work much better than ASP sessions.

Hal Levy
Web Developer, PDI Inc.

NOT a Wiley/Wrox Employee

Colonel Angus · August 13th, 2004, 09:28 AM

You bring up a good point, Hal. The reason I would have avoided sessions before .NET was to preserve resources. I am not familiar with the difference in how .NET handles sessions. How is the use of sessions improved?

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In God we trust, everything else we test.

katsarosj · August 13th, 2004, 09:39 AM

While I agree that it isn't the best way to do it, I just very easily extracted a hidden value from one page to another using the method I described above.

Add a hidden field to your first page, right-click on it and click "Run As Server Control". .Net will automatically give it an ID and Name.

You should then be able to access this value from the second page.

It isn't pretty and I wouldn't do it unless I absolutely had to, but...

J

Hal Levy · August 13th, 2004, 10:08 AM

.NET, while still consuming memory resources, have made some great improvements on the session in that it can be stored to a DB, you can use cookieless sessions .. and more.. I'd suggest you read about them before you discount them.

http://www.411asp.net/home/tutorial/...c/web/sessions has a number of links to articles on the topic.

Hal Levy
Web Developer, PDI Inc.

NOT a Wiley/Wrox Employee

Colonel Angus · August 13th, 2004, 10:29 AM

Thanks!

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In God we trust, everything else we test.