ASP.NET

Re: Kind of out of place since theis is not an ASP.NET question, but it's ASP & VB script related

26-Sep-06 8:07

You could use the Eval function to do this, but it's really not efficient, and clearly not safe.

Instead you should rethink what you are doing, and see if there is a better way to do it.

If you need to do it that way, using Select to get the right array is a safe and efficient way:

Select Case Request.QueryString("grp")
   Case "dogs": astrList = astrDogs
   Case "cats": astrList = astrCats
   Case "rats": astrList = astrRats
   Case Else: Response.Write "Error: Unknown group." : Response.End
End Select

---
b { font-weight: normal; }

RoswellNX26-Sep-06 8:21

RoswellNX

26-Sep-06 8:21

Thanks...that's exactly what i was reading about just a second ago in the tizag.com ASP tutorial, something i haven't turned to until now... the method looked about right to me so i'm glad to see a more experienced coder suggest it as well...hopefully it will not see an distinction between the value of a string and the value of the array name

Roswell Smile | :)

"Angelinos -- excuse me. There will be civility today."
Antonio VillaRaigosa
City Mayor, Los Angeles, CA

Re: Kind of out of place since theis is not an ASP.NET question, but it's ASP & VB script related

Guffa26-Sep-06 8:59

Re: Kind of out of place since theis is not an ASP.NET question, but it's ASP & VB script related

26-Sep-06 8:59

RoswellNX wrote:
hopefully it will not see an distinction between the value of a string and the value of the array name

Curious about what you mean by that... A value from the query string is always a string. If the contents of the string happens to be the same as the name of a variable, they are still unrelated.

---
b { font-weight: normal; }

RoswellNX26-Sep-06 9:17

RoswellNX

26-Sep-06 9:17

if the two values are equal there's still a chance that it might not identify the array because from what i see VBScript interprets data as objects, and it might still read the string as nothing more than a string even as that is used to select an array by name...

At first i tried to see if it will be able to simply take the value of the query string and use that to select the corresponding array, but i see that it can not take a value of a string and interpret it as the name of an array when used in a function or when generating links. But it works if i simply name the array manually in the For - Next loop.

FYI, he main purpose of the script is to take a query string and identify the array that it corresponds with, containing string values that will be used to generate the links by the For - Next loop)

Roswell

"Angelinos -- excuse me. There will be civility today."
Antonio VillaRaigosa
City Mayor, Los Angeles, CA

Re: Kind of out of place since theis is not an ASP.NET question, but it's ASP & VB script related

Guffa26-Sep-06 9:51

Re: Kind of out of place since theis is not an ASP.NET question, but it's ASP & VB script related

26-Sep-06 9:51

The value of a string will never be identified as anything in the code. You can put anything in a string, and it won't cause anything to happen. For an example:

a = 42<br />
b = "a = -1"

The variable a still contains the value 42, the string in the variable b is only treated as text.

---
b { font-weight: normal; }

RoswellNX26-Sep-06 10:09

RoswellNX

26-Sep-06 10:09

Guffa wrote:
The value of a string will never be identified as anything in the code. You can put anything in a string, and it won't cause anything to happen. For an example:

a = 42
b = "a = -1"

The variable a still contains the value 42, the string in the variable b is only treated as text.

yeah, a string is in quotes...that's what makes it look like a string in the system i guess, and what i think my problem is that i somehow let it be classified as a string and keep the quotes, while i want to turn the string value into something of a keyword to pick the right array.

But chances are that 50% of the problem is that i'm wound up and nervous right now, and it makes it that much harder to understand all the material i try to memorize w/o making sense of it beforehand...i remember bits and pieces and i try to compare it to what i know of PHP, but some of it just escapes me

Roswell

"Angelinos -- excuse me. There will be civility today."
Antonio VillaRaigosa
City Mayor, Los Angeles, CA

Re: Kind of out of place since theis is not an ASP.NET question, but it's ASP & VB script related

Guffa26-Sep-06 11:24

26-Sep-06 11:24

A string literal is written between quotes, but once the string value is assigned to a variable, there are no quotes, it's just a string value. A string is a string, and you can not turn it into an identifier.

You can use the Eval function to evaluate a string as an expression, but I strongly advice against using that. If you evaluate a value from query string without validating it first, your code is wide open for a wide range of attacks. Also IMHO, Eval is Evil. Although it has it's uses in some very rare occasions, mostly it only promotes a backwards way of solving problems.

---
b { font-weight: normal; }

Works!

RoswellNX26-Sep-06 10:38

RoswellNX

26-Sep-06 10:38

It Works!

Thanks Alot Guffa Big Grin | :-D

, You've saved the day...or at least another 45 minutes it would've taken me to figure it out Laugh | :laugh:

...

As always quotes are my worst enemy... Blush | :O

every time something doesn't work it usually means i either have an extra set or i missed one in some obscure spot...or in this case quotes identify data as a string....now it's time for a good nap after 2 sleepless nights

Roswell Sleepy | :zzz:

[edit] The reason i have to use somewhat barbabian (from the point of view of more experienced coders, to others just odd)methods to get the script to do the job is that i was going to have the data all fed from a database, which would be much cleaner, but as it turned out the server guy did not have PHP on the right machine and i had to go with something other than the expected combination of PHP & MySQL... [/edit]

"Angelinos -- excuse me. There will be civility today."
Antonio VillaRaigosa
City Mayor, Los Angeles, CA

Event Handling

jorsh26-Sep-06 7:06

jorsh

26-Sep-06 7:06

Aside from dealing with UI events (such as OnClick for Buttons) and getting at DataItems in bound controls (such as OnItemDataBound for Repeaters), I'm having a difficult time understanding why one would implement event handlers.

I've spent the last few hours searching Google and the articles and forums in this site, and while I've found plenty of great resources on HOW to implement custom event handlers, I haven't found any that explain WHY I would want to.

For example, one article (in Visual Studio's Help) gave an example of an AlarmClock. The AlarmClock would raise an Alarm event and a listener for that event would execute some code. Why is this model better than simply calling a Ring() method of the AlarmClock class?

Why would this:

protected virtual void OnAlarm(AlarmEventArgs e)<br />
{<br />
    AlarmEventHandler handler = Alarm; <br />
    if (handler != null) <br />
    { <br />
        // Invokes the delegates. <br />
        handler(this, e); <br />
    }<br />
}

be better than this:

protected void Ring()<br />
{<br />
    // do what the delegates would have done.<br />
}

Any answers (including links to articles) would be very appreciated.

Thanks,
Jorsh

Re: Event Handling

minhpc_bk26-Sep-06 15:40

Asp.Net 2.0 RSS. Need advice.

26-Sep-06 15:40

I would say it's the Naming Convention, a couple of links below might give you more information:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpgenref/html/cpconEventNamingGuidelines.asp[^]
http://msdn2.microsoft.com/en-us/library/wkzf914z.aspx[^]

shapper26-Sep-06 5:33

shapper

26-Sep-06 5:33

Hello,

First of all let me say I never worked with RSS as a developer.

I am working on a web site where I am displaying news from a database.
This part is done.

Basically, I need to make those same news available as through RSS.

I believe I need to have a XML file available and updated from the
database?

And maybe the database fields should be the same as RSS 2.0 format?

Anyway, could someone advice me on this?

Thanks,
Miguel

Re: Asp.Net 2.0 RSS. Need advice.

minhpc_bk26-Sep-06 15:41

.NET2 Dispay data from SQL2005

26-Sep-06 15:41

You might want to check out the RSS Toolkit[^]

munklefish26-Sep-06 5:09

26-Sep-06 5:09

Hi,

I need to retrieve a single record from an SQL database and then store each field of the record as a set of variables, in order that i can then display this data on the page via the codebeind.

Im new to .Net 2.0 and am using Visual Studio 2005. I've already created a stored proceedure in SQL database and created an SQLDataSource to retrieve the information. However my problem is that i dont know how to then get the record fields from the SQLDataSource to save them as variables.

Please help.

Dayekh26-Sep-06 5:19

Dayekh

26-Sep-06 5:19

I know a long winded way in which you can do this ..

Created a number of distint and simple DataGrids, each which displays ONLY 1 field from that table. They you can toggle each datagrid's visibility on and off.

This method can also be varied in a number of ways using DataLists and what not.

Hope this helps. Smile | :)

munklefish26-Sep-06 5:23

26-Sep-06 5:23

Hi,

Thanks for the answer but this seems a bit too cumbersome and inefficient for the server.

Surely there is a better way to do it? Even if it means hand coding the data retrieval from the Database.

Any ideas?

Dayekh26-Sep-06 5:38

Dayekh

26-Sep-06 5:38

By posting this, I have put your hopes up, and for that, I apologise.

Just wanna say that I have no ideas, hope someone has. I would benefit from it too.

Happy Coding.. Smile | :)

munklefish26-Sep-06 5:42

26-Sep-06 5:42

Thanks for the idea though. I just need a more robust way to do it.

Anyone got any ideas on how to help?

Keith Barrow26-Sep-06 6:25

Keith Barrow

26-Sep-06 6:25

Unfortunately, you need to "unpack" the data by hand if you need to get to manipulate the data before displaying. If not, you could bind the information from the SQLDataSource to a form view or details view.

There is a quickstart at:

http://quickstarts.asp.net/QuickStartv20/aspnet/doc/ctrlref/data/formview.aspx[^]

Hope this helps.

munklefish26-Sep-06 6:34

26-Sep-06 6:34

Ok thanks.

I thought as much. With the advances made over .NEt 1.1 i thought 2.0 might have also dealt with issues like this.

Obviously not, but still it seems 2.0 is a vast improvement in having closed the gap between the ease of using wizards and the difficulty of being able to do stuff a little more complex than eating a banana.

minhpc_bk26-Sep-06 16:10

26-Sep-06 16:10

Hi there,
Just want to add some information to the above two guys, basically there are a couple of ways that you can use to display data in the web page. You can write your code to pull data out of DB then display it in the web page by either setting the UI control's property or bind it to the data-bound control, and at least you need to write two lines of code in the case of data binding:

Line 1: control.DataSource = datasource;//set the DataSource property
Line 2: control.DataBind;//call the DataBind method to cause the binding

However, the new version of the ASP.NET, you no longer need to write this code any more. And the new set of data source controls such as SqlDataSource , ObjectDataSource controls ... will handle that for you. Though you can use the datasource control in code to pull data for example calling the Select method the accessing the IEnumerable result, you'd normally use it with the data-bound controls that have the DataSourceID property like GridView, FormView .... That being said, in the case of the controls that do not have the DataSourceID property like TextBox ... you can use your code (or the datasource control) to pull data, then set to the right property of the control in code or use the data binding expression (and remember calling the DataBind method), another option is to choose a container for it like FormView control so that you can configure using a datasource control like SqlDataSource.

munklefish27-Sep-06 5:41

27-Sep-06 5:41

Hi,

I just want to retrieve the info from the SQLDataAdapter so i can store it in variables, and then put these variables into a text string displayed in a textbox.

I tried using a formView etc but tand am able to display the data in the textboxes. However i have to buttons associated with these textboxes. One clears all data from the textboxes whilst the other submits the information in the textboxes (form).

My problem here is that when i click either button an error is thrown up saying:

<code>Object reference not set to an instance of an object.</code> In relation to any TextBox i try working with. Even though i use <code>((TextBox)FindControl("TextBox1")).Text = ""</code> to find the TextBox and then empty it (in the case of the reset action / button clicked).

Any ideas why this is or how to overcome it?

THANKS

minhpc_bk27-Sep-06 15:37

27-Sep-06 15:37

munklefish wrote:
Object reference not set to an instance of an object.

Do you mean you get this error at the server side?

Because, the textbox is placed inside a FormView which is a naming container, so make sure that you call FormView1.FindControl("TextBox1") (assuming the FormView1 is the id of the FormView control). If you simply call the FindControl("TextBox1"), it's assumed that you call the method of the Page instance, and it only searchs for the textbox in the scope of the Page, not the FormView. For more information, see Accessing ASP.NET Controls Programmatically [^]

munklefish27-Sep-06 22:33

27-Sep-06 22:33

Hi,

I tried doing this in FormView and Repeater etc etc. However it still comes up with the same error. I have also tried to FindControl using the appropriate display method as the prefix eg Repeater1.FindControl("TextBox1") but it still says the object reference is invalid.

Could this be anything to do with the fact that im using the SQLDataSource wizard and binding it on 'Page_Load' ? Ie so effectively when i click the reset or submit button in my form, the page is reloaded and thus the referenced TextBox isnt actually available for this minute period of time during which the SQLDataSource reloads the Repeater / FormView data?

Is there anyway to add the equivalent of if(!Page.IsPostBack) to stop the Data rebinding on Postback / when a button is clicked?

Thanks.

THE SOLUTION

munklefish27-Sep-06 23:47