Dynamic DropDownList City,State in ASP.NET (VB) - asp.net

I have two dropdownlists, the first is State & the second is City. I have the State ddl populated, but I would like to populate the City ddl via the selection in the State ddl. I am using autoPostBack, so it goes through the motion of updating but nothing loads. I am sure it is in the code behind or in the databind. This operation seems simple enough, if anyone has any info or a good link on a way to accomplish this, it would be greatly appreciated.
Also, after the State & city are selected I have a select button that will send the user to a gridview page with all data. That part of the page I have working and tested. It is getting the data to pass that is the issue.
I am using Stored Procs, is there a easier way to accomplish this?
Thanks in advance.

This is very simple to do and there are plenty of articles out there with full source code.
http://csharpdotnetfreak.blogspot.com/2009/03/populate-dropdown-based-selection-other.html
If you want to use the Ajax Control Toolkit, there's even a control just for that.
http://www.asp.net/ajax/ajaxcontroltoolkit/samples/CascadingDropDown/CascadingDropDown.aspx
and there are plenty of other examples using the following Bing search:
http://www.bing.com/search?q=asp.net+cascading+dropdown&form=CMDTDF&pc=CMDTDF&src=IE-SearchBox

Related

ASP.NET how to pass a reference to a particular control

I'm generally an ASP.NET MVC guy, so the "standard" ASP.NET stuff is a little difficult for me to wrap my brain around. I've tried looking for the answer, but the keywords I'm using seem to be too generic... I get a lot of close answers, but not what I'm actually looking for.
I have a grid that is populated from a data set. One of the fields is a dropdown with 4 possible statuses. When the user selects a status, an event is fired in the codebehind to make the change in the db immediately.
There is a particular status that I need to confirm, because once it's selected, it's irreversible. Figuring out how to have the back end pop up a confirmation box was annoying, but I think I have that part done now.
The problem is, if the user confirms that the status they selected for the dropdown was intended, I need to disable any further changes to that dropdown, either by disabling the control or by removing the row altogether. With this requirement, I imagine I need to pass a reference to the specific control that fired the event back to the script, so that it can pass it through the postback, where I would need to consume it.
I have no idea how to pass a reference to the control (what can be used as a reference?) and I have no idea how to use that reference in the postback.
Any help would be greatly appreciated.
;p i was waiting for you to find my post on the issue lol.
but to put it simply, you postback to the page, all members are still available to you if you instantiated something in codebehind. if not, then use FindControl to pull them from DOM. here's the passing values stuff.
as long as you don't kill the lifecycle, you're fine: Passing dropdownlist selected value to another page's dropdown list
and here is the linkspam (full docs): How do I keep TCP/IP socket open in IIS?
probably the articles on session-state and page lifecycle will be of most use.
To prompt the user for confirm add this attribute to dropdownlist.
onchange="return confirm('Confirmation Message');"

Telerik RadGrid Manipulating data from data source before databinding an item

I am working with a Telerik Radgrid on an aspx page, which basically has to bind to a datatable, which gets populated by data returned from a web service. I need to be able to fill out some of the columns in the RADGRID based on the data returned by the web service.
For example, I need to be able to build the Hyperlink column based on the parts data returned by the web service. I need a way to access the datasource before the grid item gets populated and direct execution to a routine which builds the URL for the parts on a website.
Can anybody please suggest an efficient way to do this?
I highly appreciate any help/suggestions.
Thanks
Karthik
(Moving my comment to an answer, because I'm thinking this will work out for you.)
You could always cheat and bind it to the grid, allowing you to access the data, but then hide the columns so the users could never get the data.
Let me know how it works out.
EDIT:
My select statement is "select top 5 ProductName from products"
I then created a hyperlink column and assigned the properties under the data tab as such.
When run, it makes the data clickable and when clicked, it navigates to the url seen in the SS.
That what you need?

collecting data from checkboxlist

Pretty basic question, I have a checkboxlist inside of a wizard control. I need to collect the value of all items that are checked, as well as whatever value is inside of a textbox if "other" is checked, to insert into my database during the Wizard.FinishButtonClick event. How do I do this? I need this in VB, please.
We cannot give you complete code to implement the task you want to implement, but can provide some starting point. Please go through the articles given below. Get back to us if you still have problems in implementing what you want after reading these.
Wizard control in .net
Asp.net and Vb.net wizard
Wizard control
I found all these in a simple google search.

thoughts on asp.net grid controls

All, I am creating a web application and I need to give users the ability to add/edit/delete records in a grid type control. I can't use 3rd party controls so I am restricted to just whats in the box for asp.net (datagrid or gridview) or creating my own. Any thoughts on the best direction to go in. I'd like to keep the complexity level at a dull roar :)
thanks in advance
daniel
You should definitely use edit and insert templates. All you have to do is give the button/link the command name such as insert/delete/update and you can allow the Grid to do most of all the work.
Check out this link
I think you'll learn to love the gridviews because they are pretty powerful.
Gridviews have different item templates that you can use for editing and inserting data. That'd be an easy way to go about it.
As long as you set your datakeyid property to the primary key in the database, you should be able to make template fields based off of whether or not you're editing or inserting data. The command name of the button you use to fire the event will handle the statements required for updating/inserting data.
This is a good site for some examples.
the out of the box grid is not too bad.
Here are a few links on master detail records in asp.net this should get you started on the CRUD opperations.
http://www.exforsys.com/tutorials/asp.net-2.0/displaying-master-detail-data-on-the-same-page.html http://msdn.microsoft.com/en-us/library/aa581796.aspx
http://www.bing.com/search?q=asp.net+master+detail
this is the best site for what you are after
www.Asp.Net
Data Access Tutorials controls
Master/Detail Using a Selectable
Master GridView with a Details
DetailView
Using TemplateFields in the GridView
Control
Others
Beginners Guide to the GridView
Control
The GridView Control
IN-DEPTH LOOK AT THE GRIDVIEW CONTROL

DataTable and javascript

Is there a way to avoid postbacks with gridview every time a row is added to it?
In other words, can I store the DataTable on the client and pass it on to the server control when I am done to save, rather than do postbacks every time the row is added?
I searched and searched....all I could find was web services, JSON, and I have a feeling it's redundant here...it's a simple task I am sure everyone had to do at some point.
Can anyone shed some light on this?
There is no avoiding postbacks if you're dealing with a standard ASP.NET GridView that utilizes ViewState.
You can however, disable ViewState and manually (programmatically) render the control on every page load. This will let you control every aspect of row creation/removal/updates, but you'll have to do it all manually. And yes, you'll utilize AJAX to read from or update on the server.
I don't konw of anything that lets you do that with the gridview out of the box, except the UpdatePanel, but that doesn't really count. If you want to implement I a full AJAX grid I would look into using the ListView Control, which will give you much more control over the resulting html.
Heres a great article from MSDN Magazine http://msdn.microsoft.com/en-us/magazine/cc337898.aspx

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